Physiologia doi: 10.3390/physiologia6030050

Authors: Hamda Mahboub Mariam Alnaqbi Maryam Yateem Anova Elizabeth Sebastian Malik Nasir Afzal Khan Salonaz Abdelglil Najma Mohamed Ali Suhaila Alnuaimi Fatima Ahmed Al Marzouqi Mohammad Yousuf Bin Nashooq Shaikha Ahmad Al Falasi Hanan Alsuwaidi Nandu Goswami

Background: Changes in estrogen and progesterone during the menstrual cycle could potentially influence standing-induced hemodynamic and autonomic responses. Aims and Objectives: We aimed to explore the effects of menstrual cycle phases on cardiovascular and autonomic adaptations to a virtual reality International Space Station (ISS) environment used as a microgravity analogue across varying body positions. Method: A randomized repeated-measures pilot study was conducted with two protocols (supine and standing) in an International Space Station-themed virtual reality environment involving healthy young female (n = 11, mean age 20 ± 1 years, height 160.6 ± 3 cm, weight 61.6 ± 9 kg) participants in 2 menstrual phases: follicular (n = 5, 20 ± 1 years, height 160 ± 3 cm, weight 55 ± 6 kg) and luteal phase (n = 6, mean age 20 ± 1 years, height 161.3 ± 2.4 cm, weight 67 ± 8 kg). Each protocol consisted of three stages: baseline, supine/standing, and recovery, each lasting 5 min. The data were analyzed using mixed repeated-measures analysis of variance. Results: Significant differences were observed between the two protocols from supine to standing across menstrual phases for several hemodynamic variables. Heart rate showed significant difference during the luteal phase (F(1,9) = 10.6, p = 0.01) with values from 72 bpm to 84 bpm and the follicular phase (F(1,9) = 7.4, p = 0.02) from 82 bpm to 92 bpm; diastolic blood pressure during the follicular phase (F(1,9) = 9.8, p = 0.01) from 55 mmHg to 80 mmHg; mean arterial pressure during the follicular phase (F(1,9) = 7.5, p = 0.02) from 73 mmHg to 93 mmHg; stroke index during the follicular phase (F(1,9) = 6.9, p = 0.03) from 74 mL/m2 to 51 mL/m2; and systemic vascular resistance index during the follicular phase (F(1,9) = 8.0, p = 0.02), with values from 1046 dyn*sec* m2/cm5 to 1564 dyn*sec* m2/cm5, respectively. This was a preliminary pilot study, and the results need to be confirmed with larger groups and validated hormonally. Conclusions: These exploratory pilot study results show that orthostatic-induced responses are influenced by the menstrual cycle phase. Since no non-VR control condition was included, the responses observed should be considered part of the VR-based protocol, and the exact role of the immersive virtual reality environment cannot be determined. The study showed that an ISS-themed virtual reality environment led to notable changes in cardiovascular function and autonomic responses during transitions from supine to standing postures, and these responses also varied across menstrual phases. Across most epochs, the standing protocol consistently shows higher heart rate, systolic and diastolic blood pressure, mean arterial pressure, and systemic vascular resistance index than the supine protocol, reflecting the effect of orthostatic loading in an ISS-themed virtual reality environment.

Physiologia doi: 10.3390/physiologia6030049

Authors: Christian Enrique Nava-Alcantar Israel Miguel-Andrés Marco Antonio Martínez-Bocanegra Agustín Vidal-Lesso Jorge Armando Ramos-Frutos Israel Aguilera-Navarrete Luis Ángel Ortiz-Lango

Background/Objectives: Previous studies have shown that excess body weight influences plantar pressure. However, the specific impact of Body Mass Index (BMI) on dynamic pressure distribution during different phases of walking, as well as its effect on load symmetry between the feet, requires further investigation. This study aimed to evaluate the effects of varying BMI categories on dynamic plantar pressure, spatiotemporal gait parameters, and load symmetry. Methods: A retrospective analysis of pre-existing records from 300 adults (2017–2025) classified as normal weight, overweight, and obese was conducted. Dynamic plantar pressure, contact time, and gait speed across four stance phases were assessed using baropodometric platforms. Bilateral differences were evaluated via the symmetry index (SI). Results: Overweight and obese individuals exhibited higher plantar pressures and prolonged contact times, particularly during the forefoot contact phase (FFCP) (p < 0.001). Gait speed decreased inversely with BMI across all phases. Despite these kinematic adaptations, BMI-related load asymmetry occurred only during the initial contact phase (ICP) (p < 0.001), restoring stability in subsequent phases. Conclusions: Excess body mass is associated with targeted mechanical overload of the forefoot rather than uniform stress across the foot. To manage inertia and maintain symmetry, individuals with high BMI may adopt spatiotemporal strategies that reduce speed and extend double support, potentially prioritizing stability over propulsive efficiency. These findings suggest that orthotic interventions for individuals with high BMI may benefit from prioritizing forefoot offloading, although prospective studies are needed.

Physiologia doi: 10.3390/physiologia6030048

Authors: Jiawei Andre Guo Liang Rafael Jiménez Lopez Carmen Cruz Herrera Alejandro Heredia Ciuró Valentina Beron Quilindo Jesús Zamora Tortosa Marie Carmen Valenza

Background/Objectives: Chronic Kidney Disease–Mineral and Bone Disorder (CKD-MBD) is a frequent complication of chronic kidney disease, characterized by altered bone mineral density and mineral–hormonal metabolism. Therapeutic exercise may help attenuate these alterations, but evidence remains limited. This systematic review and meta-analysis evaluated the effects of therapeutic exercise on bone mineral density and mineral–bone and hormonal biomarkers in adults with CKD, focusing on CKD-MBD-related outcomes. Methods: Following a PROSPERO-registered protocol (CRD420251245021), Scopus, PubMed, Cochrane Central Register of Controlled Trials CENTRAL, and Web of Science were searched from inception to January 2026. Randomized controlled trials, including pilot randomized controlled trials, comparing therapeutic exercise with usual care or non-exercise control conditions in adults with CKD were included. Methodological quality and risk of bias were assessed with the PEDro scale and RoB 2, respectively. Results: Six studies involving 398 participants were included. Most interventions lasted 22 to 24 weeks and used resistance or combined aerobic and resistance exercise across inpatient and outpatient settings. Qualitative synthesis suggested improvements in femoral neck and lumbar spine bone mineral density and favorable biomarker changes. The assessed outcomes included femoral neck and lumbar spine BMD, calcium, phosphorus, sclerostin, PTH, FGF23, and klotho. Meta-analysis showed significant effects favoring therapeutic exercise for bone mineral density (MD = 0.05; 95% CI: 0.03 to 0.06; p < 0.00001; I2 = 39%), mineral and bone-related biomarkers (SMD = 0.71; 95% CI: 0.42 to 0.99; p < 0.00001; I2 = 75%), and hormonal biomarkers (SMD = 1.32; 95% CI: 0.88 to 1.77; p < 0.00001; I2 = 85%). Conclusions: Therapeutic exercise may have beneficial effects on bone mineral density and selected mineral and hormonal biomarkers in adults with CKD. However, confidence in these findings is limited by the small number of studies, differences in CKD stage and exercise protocols, methodological limitations, risk of bias, and substantial heterogeneity in several pooled analyses. No definitive conclusions can currently be drawn regarding the optimal exercise modality, dose, or effects across CKD stages.

Physiologia doi: 10.3390/physiologia6030047

Authors: Iwao Emura Hiroyuki Usuda

Background: Secondary multiple organ dysfunction syndrome (MODS) has an excessively high fatality rate. The mechanisms by which sepsis and systemic inflammatory response syndrome (SIRS) induces organ dysfunction and their characteristic pathological findings and biomarkers are not fully understand. Methods: We examined 24 autopsy cases with secondary MODS and peripheral blood (PB) from 467 patients with SIRS and MODS. Results: PB cytology (presence of large scavenger receptor A-positive (SRA+) cells and an SRA index >30), systemic capillary injury, pulmonary symptoms (accumulation of neutrophils and platelet thrombi, alveolar epithelial injury and edema) and cardiac symptoms (accumulation of neutrophils and platelet thrombi, capillary injury and contraction band necrosis) were assessed for all of the cases. The 467 patients were classified into group A (negative for large SRA+ cells), group B (positive for large SRA+ cells, and SRA index <30) and group C (positive for large SRA+ cells, and SRA index >30). Group C patients exhibited a significantly lower survival rate (p < 0.001). Conclusions: It was concluded that: (1) the simultaneous presence of large SRA+ cells and an SRA index >30 appear to play a central role in the development of secondary MODS, and could be a useful predictor of poor prognosis in patients with SIRS or MODS; (2) the essential histopathological lesion associated with secondary MODS pathogenesis is systemic capillary injury; and (3) the PB, lung and heart findings mentioned above are characteristic morphological findings suggestive of secondary MODS; (4) a possible mechanism for the development of secondary MODS was proposed.

Physiologia doi: 10.3390/physiologia6030046

Authors: Jean Marc Pujo Latifa Hamdaoui Marwa Lakhrem Dewi Yunia Fitriani Hajer Ben Saad Ons Boudawara Tahia Boudawara Majed Kammoun Hatem Kallel Ibtissem Ben Amara

Objective: This study investigated the effects of three chronic stress exposure models (permanent elimination, forced swimming, and food and water deprivation) on bone oxidative stress, structure, and metabolism in vivo. Methods: Adult rats were exposed to different stress conditions, while control animals were maintained under standard laboratory conditions. Bone morphological and histological parameters, oxidative stress biomarkers, antioxidant defense system, and mineral concentrations were assessed. Results: Stress exposure resulted in significant reductions in body weight, femur weight, and femur length compared to controls. A marked increase in oxidative stress biomarkers was observed in bone tissue, including lipid peroxidation, reactive oxygen species, hydroperoxides, hydrogen peroxide, protein carbonyls, and advanced oxidation protein products. In contrast, antioxidant defenses, including enzymatic activities and levels of glutathione, non-protein thiols, and vitamin C, was significantly decreased. Bone calcium and phosphorus levels were reduced, whereas their plasma concentrations were increased following stress exposure. Histological analysis confirmed the biochemical alterations, suggesting that chronic stress can disrupt bone integrity via oxidative mechanisms. Conclusions: These findings highlight the need for strategies to control and reduce stress-related disorders to maintain skeletal health under various chronic stress conditions.

Physiologia doi: 10.3390/physiologia6030045

Authors: Fanel Dorel Scheaua

Calcium (Ca2+) and magnesium (Mg2+) are essential divalent cations whose homeostasis is essential for cardiovascular, muscular and metabolic function. Absolute or relative imbalances between Ca and Mg can lead to cardiovascular, metabolic and neurological pathologies. Ionized calcium (Ca2+) is a biologically active fraction of plasma calcium that is tightly regulated by protein binding, phosphate complexation, magnesium modulation and acid–base status. Ionized calcium plays a central role in multiple physiological processes and is strongly influenced by plasma pH, phosphate concentration and magnesium levels. However, the combined effects of these parameters are difficult to evaluate intuitively because of their nonlinear interactions. In this study, a numerical simulation framework was used to explore how simultaneous variations in pH, phosphate and magnesium may influence ionized calcium under typical physiological plasma conditions as a phenomenological framework linking ionic equilibrium with viscosity-dependent flow parameters under well-mixed plasma conditions. The simulations reveal phenomenological changes in which concurrent increases in pH and phosphate or reductions in magnesium produce disproportionately large decreases in ionized calcium. Within the physiological ranges examined, the results also indicate a region of relative stability for ionized calcium corresponding to Ca/Mg ratios close to 3, while this value should be interpreted as an emergent feature of the modeled parameter space rather than a universal physiological constant. These findings illustrate the importance of considering multiple electrolyte interactions simultaneously when evaluating calcium homeostasis and may provide a conceptual framework for further experimental investigation.

Physiologia doi: 10.3390/physiologia6020044

Authors: Guilherme Pereira Saborosa Luciano Bernardes Leite Pedro Forte Bruno de Casio Coelho Rafael Peixoto Alexandra Malheiro Pedro Afonso Ana Claudia Pelissari Kravchychyn Cintia Campolina Duarte Rocha da Silva Christiano Eduardo Veneroso Nuno Pimenta Tiago Rafael Moreira Helton de Sá Souza Sandro Fernandes da Silva

Background/Objectives: Caffeine is a widely used ergogenic aid; however, evidence regarding its effects on neuromuscular and metabolic responses during resistance training remains limited. Therefore, this study aimed to analyze the effects of caffeine supplementation on blood glucose concentration and neuromuscular activation, assessed through electromyographic activity, during a muscular endurance test. Methods: Eleven resistance-trained men (25.7 ± 5.9 years) participated in this randomized, double-blind, crossover trial. Six laboratory visits were conducted, including one-repetition maximum (1RM) and maximal voluntary isometric contraction (MVIC) testing in the bench press exercise. From the second visit onward (baseline; BL), participants completed a 24 h dietary recall (24hDR), pre- and post-exercise blood glucose assessments, and a muscular endurance test performed at 80% of 1RM until concentric failure, while electromyographic activity was recorded from the clavicular and sternal portions of the pectoralis major, triceps brachii, and anterior deltoid. From the third visit onward, participants received one of the following randomized interventions 60 min before testing: low-dose caffeine (LC = 3 mg·kg−1), high-dose caffeine (HC = 6 mg·kg−1), low-dose placebo (LP = 230 mg), or high-dose placebo (HP = 460 mg). Results: There was an increase in the number of repetitions in all conditions vs. BL, with no significant differences (p > 0.05). Electromyographic activity did not differ between conditions (p > 0.05). Blood glucose decreased post-test in BL and placebo conditions (p < 0.05) but remained stable with caffeine (p > 0.05). Conclusions: Low and high doses of caffeine did not significantly affect muscular endurance performance or neuromuscular activation. However, caffeine supplementation appeared to attenuate the post-exercise decline in blood glucose concentration following exercise performed to concentric failure.

Physiologia doi: 10.3390/physiologia6020043

Authors: Caleb S. Clay Noah J. Perez Payton E. Miller John W. Farrell

Objective: The purpose of this exploratory study was to examine mean differences, reliability, and agreement between CP and W′ derived from a 3MAT performed after an ICT and values obtained during a standalone 3MAT performed on a separate day. Methods: Ten recreationally trained cyclists and triathletes completed four laboratory visits, including an ICT followed by a 3MAT after 30 min of recovery (same-day condition) and a standalone 3MAT performed on a separate day. CP and W′ were derived from both conditions and compared using paired t-tests and Bland–Altman agreement methods. Results: No systematic differences, but limited individual-level agreement were observed between same-day and separate-day conditions for CP (mean difference: 1.72 ± 36.5 W) or W′ (mean difference: 0.99 ± 5.9 kJ), with trivial to small effect sizes. Peak VO2 values were also not significantly different across testing conditions (p = 0.483). However, Bland–Altman analysis revealed wide limits of agreement for both CP (−69.8 to 73.3 W) and W′ (−10.7 to 12.7 kJ), indicating substantial variability at the individual level. Conclusions: Although same-day testing does not introduce systematic bias in CP or W′ estimation, the wide limits of agreement suggest that these protocols are not interchangeable for individual monitoring. Same-day testing may be appropriate for group-level assessments but should be used with caution when applied to individual athlete monitoring.

Physiologia doi: 10.3390/physiologia6020042

Authors: Carlos Andrés Restrepo-Pardo Jenny Lorena Mejia-Idarraga Luisa Matilde Salamanca-Duque Zarita Naranjo-Gutierrez Carlos Andrés Naranjo-Galvis

Background: Exercise adaptation is increasingly recognized as an immunometabolic process driven by coordinated interactions among inflammatory signaling, mitochondrial regulation, metabolic homeostasis, and recovery-associated physiology. Within this framework, NLRP3 inflammasome activation and PPARD-mediated metabolic signaling have emerged as biologically relevant pathways potentially involved in exercise-induced physiological adaptation. However, the contribution of regulatory genetic variations linking these pathways remains poorly characterized. Objective: To synthesize current evidence regarding the integration of NLRP3- and PPARD-related pathways in exercise immunometabolism and adaptive physiological responses to exercise, with particular emphasis on the regulatory variants NLRP3 rs10754558 and PPARD rs2267668 as potential contributors to interindividual variability in exercise adaptation. Methods: A structured narrative review complemented by exploratory systems-level in silico analyses was conducted using the PubMed, Scopus, and Web of Science databases until March 2026. Evidence related to exercise physiology, inflammatory regulation, metabolic adaptation, and exercise-associated phenotypes involving the NLRP3 and PPARD pathways was evaluated. Complementary analyses included functional annotation, protein–protein interaction network analysis, and pathway enrichment using STRING, Reactome, KEGG, Gene Ontology, and other publicly available genomic databases. Particular attention was given to the functional and regulatory context of rs10754558 and rs2267668 within the interconnected inflammatory and metabolic pathways relevant to exercise adaptation. Results: The reviewed evidence identified recurrent interactions among the inflammatory and metabolic pathways involved in exercise adaptation and recovery. NLRP3 rs10754558 and PPARD rs2267668 were identified as candidate regulatory variants potentially positioned at the interface between inflammatory responsiveness and metabolic flexibility, providing a biologically plausible framework for understanding the interindividual variability in exercise adaptation. Exploratory system-level analyses identified recurrent associations among inflammatory signaling, mitochondrial function, energy-sensing pathways, and metabolic regulation. These findings primarily reflect the functional annotations and system-level pathway associations identified through exploratory analyses. Conclusions: Current evidence supports a systems-level physiological framework in which inflammatory and metabolic pathways interact dynamically during exercise adaptation and recovery. NLRP3- and PPARD-related pathways, including the candidate regulatory variants rs10754558 and rs2267668, may contribute to interindividual variability in exercise-associated physiological responses and represent promising targets for future hypothesis-driven investigations in exercise immunometabolism, exercise genomics and precision exercise medicine.

Physiologia doi: 10.3390/physiologia6020041

Authors: João Victor Batista Cabral Maria Mariana Barros Melo da Silveira Amanda Tavares Xavier Fábio Henrique Portella Corrêa de Oliveira Wilma Tatiane Freire de Vasconcelos Thaysa Maria Gama Leão de Albuquerque Menezes Keylla Talitha Fernandes Barbosa Leuridan Cavalcante Torres Dário Celestino Sobral Filho Dinaldo Cavalcanti de Oliveira

Congenital heart defects represent prevalent malformations requiring complex surgical interventions. Outcomes are influenced by clinical severity, inflammatory response, and complexity of care, highlighting the need for improved risk stratification tools. Objectives: To describe the behavior and distribution of perioperative sTREM-1 concentrations in a pediatric cohort undergoing cardiac surgery, exploratorily stratified by RACHS-1 and TISS-28 severity scores. Methods: A translational cross-sectional study was conducted with 32 children (aged 0–14 years) undergoing surgical correction for congenital heart disease at a Brazilian public referral hospital (2021–2022). Exclusion criteria included genetic syndromes, active infections, or previous cardiac surgeries. Clinical severity was assessed using RACHS-1 (mortality risk) and TISS-28 (care complexity) scores. Serum sTREM-1 levels were measured via ELISA preoperatively and postoperatively. Statistical analysis involved the Shapiro–Wilk normality test, descriptive statistics expressed as medians and interquartile ranges, and Spearman’s rank correlation coefficient to evaluate the relationship between sTREM-1 levels and severity scores, with significance set at p < 0.05. Results: The cohort consisted predominantly of males (56.25%), term infants (93.75%), with 50% presenting cyanosis. RACHS-1 category 3 was most common (34.37%), while TISS-28 category 2 predominated (40.62%). Most patients were discharged (93.75%). Preoperative sTREM-1 levels showed no significant correlation with RACHS-1 (r_s = 0.265; p = 0.143) or TISS-28 scores (r_s = 0.227; p = 0.212). Conversely, postoperative sTREM-1 concentrations significantly and positively correlated with both RACHS-1 (r_s = 0.356; p = 0.045) and TISS-28 categories (r_s = 0.394; p = 0.026), reflecting higher biomarker levels in more severe clinical scenarios. Conclusions: Postoperative sTREM-1 levels correlated significantly with surgical risk and clinical severity, showing higher median concentrations in more severe RACHS-1 and TISS-28 categories. Conversely, no preoperative correlation was observed, suggesting sTREM-1 primarily reflects postoperative inflammatory responses and surgical complexity.

Physiologia doi: 10.3390/physiologia6020040

Authors: Philip J. Atherton

The open access journal Physiologia [...]

Physiologia doi: 10.3390/physiologia6020039

Authors: Gema Chopo-Escuin Jorge A. Quílez Cecilia Sosa Natalia Guillén Víctor Sorribas

Background: The regulation of inorganic phosphate (Pi) homeostasis is predominantly mediated by the Pi transporters belonging to the SLC34 and SLC20 families of solute carriers. However, not all Pi handling can be explained by these transporters. In this study, we sought to identify novel Pi transporters in accordance with prior findings on inhibition patterns. Methods: We have performed a functional screening of new Pi carriers using the Xenopus laevis oocyte expression system, focusing on the SLC26 family, and corroboration in cell culture. Results: Both SLC26A7 and SLC26A9 have been shown to express sodium-activated Pi uptakes with approximately 200 µmol/L Pi affinity. In both cases, Pi transport is inhibited by increasing pH and by phosphonoformate, arsenate, bicarbonate, sulfate, the chloride channel inhibitor 5-nitro-2-[(3-phenylpropyl)amino]-benzoate, and several transport site and translocation inhibitors of bicarbonate exchangers. In addition, the CFTR inhibitor GlyH-101 and the SLC4 inhibitors DIDS, SITS, and phloretin exhibited partial inhibition of SLC26A9-mediated Pi uptake. The endogenous expressions of both SLC26A7 and SLC26A9 in the renal cell lines LLC-PK1 and MDCK were primarily intracellular, colocalizing with endosomes, lysosomes, and the trans-Golgi network markers. Conversely, plasma membrane expression was found to be minimal. Pi transport in MDCK cells was sodium-independent, but when either SLC26A7 or SLC26A9 was overexpressed, sodium-activated Pi uptake was observed, along with increased expressions of SLC26A7 or SLC26A9 in the plasma membrane. Conclusions: Sodium-activated Pi transport is a novel function of the SLC26A7 and SLC26A9 multifunctional anion transporters. Further research is necessary to ascertain the relevance to Pi homeostasis in vivo.

Physiologia doi: 10.3390/physiologia6020038

Authors: Elizaveta Skverchinskaya Irina Antonova Elena Filatova Polina Sylko Stepan Gambaryan Igor Mindukshev

Background/Objectives: Chronic ethanol consumption damages erythrocyte membranes, reducing their deformability and disrupting erythropoiesis. Dopaminergic signalling plays an important role in regulating haematopoietic stem cells. However, the impact of genetic alterations in the dopamine system on the functional properties of erythrocytes and their resistance to the toxic effects of alcohol remains understudied. In this study, we evaluated haematological parameters and the sensitivity of erythrocytes to chronic ethanol exposure in DAT-HET rats (heterozygous for the dopamine transporter gene) compared to Wistar rats. Methods: Both lines of rats were subjected to chronic alcoholisation (10% ethanol for six months). Flow cytometry was used to assess reticulocyte production, intracellular esterase activity (cell viability), and membrane lipid asymmetry disruptions. Laser diffraction was used to evaluate osmotic resistance (deformability). Results: The partial knockout of the DAT gene significantly altered the baseline haematological profile, resulting in pronounced leukopenia, moderate thrombocytopenia, moderate erythrocyte macrocytosis, and reduced intracellular esterase activity. The consequences of chronic ethanol consumption in Wistar rats (anaemia, decreased reticulocyte count, increased osmotic rigidity of erythrocytes, and an increased proportion of annexin-positive cells) were similar to those observed in humans, thus confirming the validity of the experimental model. In contrast, chronic alcohol exposure did not significantly influence haematopoiesis parameters or erythrocyte biophysical properties in DAT-HET rats, indicating that even a 50% loss of the dopamine transporter strongly prevented ethanol’s damaging effects on blood cells. Conclusions: The marked contrast between Wistar rats (which develop alcohol-induced anaemia and erythrocyte dysfunction similar to humans) and DAT-HET rats (which remain largely unaffected) demonstrates that dopaminergic signalling plays a previously unrecognised role in determining erythrocyte sensitivity to alcohol toxicity.

Physiologia doi: 10.3390/physiologia6020037

Authors: Iris Prestanti Anastasios Vamvakis Ilektra Toulia Parthena Savvidou Aikaterini Theodosiadi Eleni G. Paschalidou Antonios Bogiatzoglou Maria G. Grammatikopoulou Dimitrios G. Goulis Kyriaki Tsiroukidou Pascal Izzicupo

Background: Youth with type 1 diabetes (T1D) often show low physical activity levels and a long time spent in sedentary and poor sleep, which may worsen their health. This study aimed to describe baseline movement and sleep patterns in children and adolescents with T1D and compare them with behaviors recorded during a structured summer camp. Methods: Twenty-three participants (13.33 ± 2.13 years) completed physical fitness tests, self-report questionnaires, and 7–8 days of wearable monitoring before camp. During a 10-day diabetes summer camp, participants continued wearing the devices to track physical activity, sedentary time, and sleep. Comparisons between pre- and during-camp periods were performed using paired statistics, and linear regressions examined associations between activity and sleep awakenings. Results: At baseline, device-based monitoring showed low physical activity levels, long sedentary time and poor sleep. Self-reported data confirmed low activity levels and long time spent in sedentary activities, especially screen time. During camp, daily steps increased significantly (p < 0.001), as well as all the physical activity intensities (p < 0.01). Sedentary time decreased significantly (p < 0.001), and sleep duration declined (p < 0.001), but awakenings were shorter (p = 0.005). Baseline sedentary time predicted longer nocturnal awakenings, while greater increases in steps during camp correlated with longer awakenings. Conclusions: Children and adolescents with T1D showed low baseline activity, high sedentary time, and poor sleep. Participation in the structured summer camp appears to be associated with changes in physical activity, sedentary behavior, and sleep patterns.

Physiologia doi: 10.3390/physiologia6020036

Authors: Evgenia D. Cherouveim Panagiotis G. Miliotis Anastasios Makris Maria D. Koskolou Konstantina Dipla Ioannis S. Vrabas Nickos D. Geladas

Background/Objectives: This study evaluated carotid baroreflex sensitivity (cBRS) during graded exercise tests to exhaustion in healthy individuals. It aimed to elucidate whether the augmented blood pressure response during heavy- and maximal-intensity dynamic exercise alters carotid baroreflex control of heart rate and contributes to exercise intolerance. Methods: Thirteen healthy males (age 33 ± 2 yrs, body mass 74.6 ± 2.4 kg, and V˙O2max 54.12 ± 1.88 mL·kg−1·min−1) performed a 4 min constant-load cycling exercise at low—(30% PPO), moderate—(60% PPO), high—(80% PPO), and maximal—(100% PPO) intensity, in two experimental conditions: (a) with unrestricted muscle blood flow (no-BFR) and (b) with partial muscle blood flow restriction (BFR). Results: A significant decline in cBRS was observed during the graded maximal exercise test compared to baseline (p < 0.001), accompanied by an upward and rightward relocation of the linear relationship between systolic blood pressure (SBP) and heart rate (HR). However, the magnitude of cBRS reduction was attenuated towards maximum exercise. Application of BFR during exercise exaggerated the blood pressure rise (p < 0.01), the perceptual response (p < 0.001), the exercise-induced cBRS reduction (p < 0.001), and induced a further relocation of the SBP-HR relationship. Additionally, BFR limited the HR increase and resulted in reduced exercise performance compared to the no-BFR condition. Conclusions: These findings suggest that the pronounced increase in blood pressure during heavy- and maximal-intensity exercise may limit further increases in heart rate through arterial baroreflex activation. This may contribute to reduced exercise tolerance, as evidenced by the lower peak power output and attenuated maximal heart rate observed in muscle BFR condition.

Physiologia doi: 10.3390/physiologia6020035

Authors: Issei Sugimoto Yugo Kimura Yasuyuki Umezaki Hiromi Izawa Takumi Saito Sumika Ogawa Atsunori Itagaki Ikue Kondo Tomohito Nunomura Sangun Lee

Background/Objectives: The combined effects of aerobic exercise and normobaric hyperoxia exposure on skeletal muscle in diabetes mellitus (DM) remain unclear. This study investigated whether their combination influences skeletal muscle capillary and mitochondrial function in diabetic rats. Methods: Seven-week-old male Wistar rats were randomly assigned to the following five groups: control (CON), DM, DM with aerobic exercise (DMEx), DM with aerobic exercise under 30% oxygen exposure (DMEx30), and DM with aerobic exercise under 50% oxygen exposure (DMEx50). Aerobic exercise and normobaric hyperoxia exposure were performed simultaneously in the DMEx30 and DMEx50 groups. Results: Combined aerobic exercise and normobaric hyperoxia significantly improved both capillary density and succinate dehydrogenase (SDH) activity in the soleus muscle, which is predominantly composed of slow-twitch fibers, in diabetic rats. In contrast, the effects were more limited in predominantly fast-twitch muscles, including the extensor digitorum longus and plantaris muscles. Conclusions: Combined aerobic exercise and normobaric hyperoxia may induce beneficial skeletal muscle adaptations in diabetic rats, with more pronounced effects in the predominantly slow-twitch soleus muscle than in predominantly fast-twitch muscles. These findings suggest that muscle fiber-type composition may influence responsiveness to this intervention. This combined approach may contribute to the development of novel exercise-based interventions for DM.

Physiologia doi: 10.3390/physiologia6020034

Authors: Dilshodbek Mamajonov Nazokat Tukhtaboeva Alisher Izatulayev

Background/Objectives: This study examined the effects of an eight-week plyometric training programme on jump biomechanics, field-based jump performance, and repeated-jump endurance in 13–14-year-old volleyball players, and explored training-induced changes. Methods: A pre–post controlled experimental design was used. Thirty male volleyball players aged 13–14 years were assigned to an experimental group (EG, n = 15) or a control group (CG, n = 15). The EG completed a structured plyometric programme three times per week for eight weeks in addition to regular volleyball training, whereas the CG continued usual practice. Biomechanical variables were assessed during the Repeated Countermovement Jump test using the BTS Bioengineering G-Walk inertial measurement system, together with field-based jump and repeated-jump endurance tests. Outcomes were analysed using two-way mixed ANOVA (Group × Time). Δ-based correlations were examined using Pearson and Spearman coefficients with false discovery rate correction. Results: Significant Group × Time interaction effects were found for all analysed RCMJ variables (all p < 0.001). Significant interaction effects were also observed for all field-based jump and repeated-jump endurance outcomes (all p ≤ 0.025). The EG showed greater improvements over time than the CG across the principal biomechanical, practical, and endurance-related indicators. Correlation analysis revealed strong associations among the principal RCMJ variables and selected links with field-based and endurance measures. Conclusions: A structured plyometric programme may improve jump biomechanics, jump performance, and repeated-jump endurance in adolescent volleyball players. These findings should be interpreted cautiously because of baseline differences, the modest sample size, and the IMU-derived nature of force- and power-related estimates.

Physiologia doi: 10.3390/physiologia6020033

Authors: Jason Simpson Matthew Ott Andrew Killgore Nuno Oliveira Jon Stavres Austin J. Graybeal Megan E. Renna Tanner A. Thorsen

Background/Objectives: Metabolic syndrome (MetS) is a cluster of cardiometabolic risk factors that increases the risk for cardiovascular disease. Although gait impairments are documented in older adults with MetS, few studies have examined gait biomechanics or the potential for gait-related measures to differentiate metabolic syndrome status in young adults. This study examined whether gait biomechanics, functional gait performance, and muscle strength are associated with MetS risk factors in young adults, and whether these measures predict MetS classification. Methods: Twenty-four young adults meeting criteria for metabolic syndrome (MetS+) and 24 participants without MetS (MetS−) completed cardiometabolic assessments, gait analysis, functional gait testing, and lower extremity isometric strength testing. Multiple linear regression examined associations between gait velocity and MetS risk factors, and binary logistic regression assessed the ability of biomechanical, functional, and strength variables to differentiate MetS status. Results: Compared with matched controls, MetS+ participants demonstrated slower gait velocity, longer stance time, and lower propulsive ground reaction forces. Regression models examining MetS risk factors did not significantly explain variance in gait velocity. Logistic regression indicated that spatiotemporal gait parameters and GRF variables could differentiate MetS classification with fair predictive ability, whereas functional gait performance and strength measures showed limited classification performance. Conclusions: Young adults with MetS demonstrated modest differences in select gait variables, but the MetS risk factors did not show strong relationships with gait velocity in regression analyses. Spatiotemporal gait parameters differentiated MetS+ and MetS− groups but offered limited predictive value. These findings suggest that subtle biomechanical differences may be present early in the progression of MetS, although stronger functional impairments may not yet be detectable in young adults.

Physiologia doi: 10.3390/physiologia6020032

Authors: Aidan O’Malley Chrissie Ho Maddie McDonell Alexandra Martiniuk Tora Sibbald Lauren Ha Damian Ragusa Kylie Brown Allan Ben Smith David Mizrahi

Background: Childhood cancer survivors commonly experience long-term treatment effects that impair physical function. Access to in-person physical fitness assessments is often limited by geographic, logistical, and resource constraints. Virtually supervised physical fitness assessments may offer a feasible alternative; however, evidence in this population remains limited. Methods: This study evaluated the feasibility of delivering virtually supervised physical fitness assessments via videoconference for children and adolescents aged 5–18 years following completion of cancer treatment. Assessments evaluated lower-body strength (30 s sit-to-stand), upper-body strength (30 s push-up), mobility (timed up-and-go), balance (single-leg balance), aerobic endurance (two-minute step), and flexibility (sit-and-reach). Pre-defined feasibility benchmarks included recruitment (≥15 participants within three months), assessment completion (≥85% of participants completing all six assessments), individual assessment completion (≥90% of planned assessments completed), technique fidelity (≥85% of assessments performed with correct technique), session duration (≥90% of sessions completed in ≤30 min), safety (no adverse events), and participant satisfaction (qualitative feedback). Results: Twenty-nine participants were enrolled, with 28 completing the virtual assessments. The sample (61% male) had a mean age of 9.8 ± 3.7 years (range 5–16), with acute lymphoblastic leukaemia the most common diagnosis (46%). Recruitment exceeded benchmarks (23 participants within three months). Assessment completion was 92.9% (26/28), individual assessment completion was 98.8% (166/168), and technique fidelity was 90.9%, with the lowest fidelity for push-ups (73.1%). Most sessions were completed within 30 min (92.9%; median 19.5 min, range 15–33). No adverse events occurred. Feedback indicated high satisfaction, highlighting convenience, engagement, and practicality. Conclusions: Virtually supervised physical fitness assessments were feasible, safe, and acceptable for childhood cancer survivors. These findings provide initial feasibility evidence to support further validation and implementation research before broader clinical application.

Physiologia doi: 10.3390/physiologia6020031

Authors: Polyxeni Spiliopoulou Gerasimos Terzis

The purpose of this narrative review was to describe the maximal strength, muscle power, rate of force development, and muscle morphology of athletes across different ski disciplines. Specifically, this review synthesizes evidence on upper- and lower-body maximal strength both dynamically and isometrically, muscle power through jumping performance and rate of force development, and muscle morphology in competitive skiers. Furthermore, it examines how these neuromuscular parameters adapt when resistance-training interventions are incorporated into athletes’ routine training programs. Following a literature search, 30 studies met the inclusion criteria, 18 describing the ski athletes’ characteristics mentioned above and 12 evaluating the effects of resistance-training interventions. Altogether, these studies involved 561 participants, with ages ranging between 14.6 ± 1.1 years and 35 years. Overall, the above characteristics of ski athletes appear to align with sport-specific demands, which vary across ski disciplines. The resistance-training protocols applied in this population are predominantly high-load resistance training and it appears that resistance training may benefit from increased emphasis in ski-specific preparation. However, training programs tailored to the specific demands of each discipline are recommended.

Physiologia doi: 10.3390/physiologia6020030

Authors: Boryi A. Becerra-Patiño Juan David Paucar-Uribe Carlos Felipe Martínez-Benítez Valeria Montilla-Valderrama Armando Monterrosa Quintero Mert Kurnaz Rodrigo Yáñez-Sepúlveda José Francisco López-Gil

Objective: Analyze physical fitness variables and body composition to define patterns or similarities in performance using principal component analysis. Materials and Methods: Sixty-eight players participated in the study, divided into three groups according to their age: Under-13 (n = 23), Under-15 (n = 27) and Under-17 (n = 18). A comparative cross-sectional study was performed. The variables analyzed were squat jump, countermovement jump, countermovement jump with arms, hamstring strength, COD-Timer 5-0-5, COD-Timer 5 + 5, speed (5, 10, 15 m), and running anaerobic sprint test. Body composition variables were skinfold thickness, diameters, and circumferences. Results: For the squat jump, 10.4% of the variability in speed (η2 = 0.104) and 12.5% of the variability in jump height (η2 = 0.125) are explained by category, both with moderate effect sizes. For the countermovement jump, 10.8% of the variability in speed (η2 = 0.108) and 13.2% of the variability in jump height (η2 = 0.132) are explained by category, both with moderate effects. For the running anaerobic sprint test power test, a large effect size was determined for each of the six times, indicating that at least 57.4% of the variability in time is explained by category. Conclusions: Two control groups were identified according to category (Under-13, Under-15, Under-17), revealing that principal component 1 and principal component 2 were significant in the performance of anthropometric variables such as residual mass, bi-styloid diameter, arm span, and residual mass, and physical variables, specifically related to COD-Timer 5 + 5, COD-Timer 5-0-5, and speed.

Physiologia doi: 10.3390/physiologia6020029

Authors: Xundian Liu Jinxuan Bao Yaxuan Huang Xiuying Jiang

Background/Objectives: This systematic review examined whether oral vitamin D supplementation improves vitamin D status, health, and exercise outcomes in indoor-training aquatic athletes. Methods: We systematically reviewed randomized, placebo-controlled trials (>2 weeks) investigating vitamin D supplementation in competitive swimmers and divers. Six eligible trials (n = 246) were included and summarized descriptively. Results: Supplementation (2000–5000 IU/day for 12 weeks to 6 months) consistently increased serum 25(OH)D compared with placebo, with average increases up to 9.3 ng/mL. While higher doses occasionally improved muscle strength and lean mass, evidence showed no consistent benefits for swimming performance, immune function, or bone turnover. Additionally, higher body mass index (BMI) correlated with smaller 25(OH)D increases. Conclusions: Vitamin D effectively corrects deficiencies in aquatic athletes but lacks consistent ergogenic benefits. Therefore, in practice, supplementation should serve primarily as a targeted corrective measure for deficiency to support fundamental musculoskeletal health, rather than a generalized strategy for performance enhancement.

Physiologia doi: 10.3390/physiologia6020028

Authors: Julio Martín-Ruiz

Background/Objectives: To develop and internally validate multiple linear regression models to predict estimated VO2max from anthropometric variables and easily obtainable physical fitness tests in active university students and to compare model performance when estimated VO2max was derived from the Rockport Walk Test versus the 20-m Shuttle Run (Course Navette). Methods: Anthropometric variables and physical fitness indicators, including body mass index (BMI), Ruffier index, and burpee repetitions, as well as sex and age, were evaluated. Estimated VO2max was obtained separately from the Rockport Walk Test and the 20-m Shuttle Run using their respective field test equations. For each test, a multiple linear regression model was fitted using the same set of predictors. Model performance was assessed using apparent metrics and internal validation with optimism correction based on repeated cross-validation. Results: The Rockport walk test model showed better predictive performance, explaining 55.2% of the variability in estimated VO2max (R2 = 0.552; adjusted R2 = 0.498) with a lower prediction error (RMSE = 3.54 mL·kg−1·min−1). In contrast, the 20-m shuttle run model showed lower explanatory capacity (R2 = 0.319; adjusted R2 = 0.256) and a substantially higher prediction error (RMSE = 11.93 mL·kg−1·min−1). Internal validation reduced performance in both models, more markedly in the 20-m shuttle run, where the corrected R2 fell to 0.163 and the corrected RMSE increased to 13.18 mL·kg−1·min−1, compared with 0.338 and 4.37 mL·kg−1·min−1 in the Rockport walk test. Conclusions: Estimated VO2max can be predicted pragmatically using low-cost models based on simple variables in a university setting; however, model performance depends on the field test used. The Rockport walk test appears more suitable for prediction using general-purpose predictors, whereas the 20-m shuttle run may require more test-specific predictors and external validation before application beyond the development sample.

Physiologia doi: 10.3390/physiologia6020027

Authors: Albena Alexandrova Lubomir Petrov Borislava Petrova Milena Zdravcheva Iveta Bonova Tanya Sheytanova

Background: The number of people working in Antarctica has steadily increased. Identifying the characteristic functional changes in polar expeditioners can help preserve health, enhance work capacity, and improve adaptive potential in specific environments. Objective: This study aimed to evaluate the impact of a short-term (30-day) expedition in Antarctica on selected physiological parameters among expedition participants, depending on their body mass index (BMI). Methods: Thirty-four expedition members, divided into 3 BMI groups, were examined before and after a one-month stay in Antarctica. The assessments included anthropometry, body composition analysis, blood pressure (BP) evaluation, and a cycle ergometer stress test, performed up to 85% of predicted maximal heart rate (PWC85%) with gas analyses and heart rate measured at the 3rd minute after exercise completion (HR3’), used as an indicator of cardiovascular recovery. Results: After the expedition, the participants with normal weight showed a modest but significant increase in body weight and BMI, and non-significant increases in fat mass (FM) and muscle mass (MM); cardiovascular recovery and physical working capacity were improved, while aerobic fitness remained unchanged. In the overweight group, post-expedition body weight and BMI did not change significantly, although small reductions in FM and improvements in MM, BP, PWC85%, and HR3’ were observed. Returning, the participants with obesity demonstrated non-significant improvements in body composition and modest declines in BP, together with a significant improvement in HR3’. Conclusions: Comparative analysis revealed significant differences in post-expedition changes in several functional parameters between the normal-weight and obese groups. Overall, the Antarctic expedition elicited beneficial cardiovascular and functional adaptations, particularly among overweight individuals, while body composition and aerobic capacity remained unchanged across all groups.

Physiologia doi: 10.3390/physiologia6020026

Authors: Jagoš Golubović Đula Đilvesi Bojan Jelača Sanja Maričić Prijić Petar Vuleković

Background: Contemporary aneurysm surgery increasingly requires the management of complex lesions with limited physiological reserve. A growing “physiology-first” paradigm emphasizes that optimizing cerebrovascular dynamics during aneurysm treatment is essential for favorable neurological outcomes. Methods: This narrative review synthesizes current evidence and expert perspectives on cerebrovascular physiology relevant to aneurysm surgery, including cerebral perfusion, autoregulation, ischemia tolerance, neuroprotection, and intraoperative monitoring. Results: Key themes include individualized blood pressure management, recognition of impaired autoregulation—particularly after subarachnoid hemorrhage—safe application of temporary arterial occlusion, and the use of multimodal neuromonitoring to detect ischemia in real time. The strengths and limitations of neuroprotective adjuncts are critically discussed in the context of available clinical evidence. Conclusions: Integrating cerebrovascular physiology into aneurysm surgery supports informed intraoperative decision-making, minimizes ischemic injury, and enhances patient outcomes. A physiology-first approach complements technical expertise and represents a cornerstone of modern neurovascular practice.

Physiologia doi: 10.3390/physiologia6020025

Authors: Renato Méndez-DelCanto Felipe J. Aidar Alfonso López Díaz-de-Durana Esteban Aedo-Muñoz Ciro José Brito Nuno Domingos Garrido Victor Machado Reis Pantelis T. Nikolaidis

Background: As Para-Powerlifting (PP) athletes need the maximum bench press concentric strength performance during competitions, the velocity of the eccentric phase could be critical to the sport’s success. Methods: Through eccentric tempo modification, normative, faster, and slower bench press eccentric velocities were tested on 16 experienced PP athletes. Mean propulsive velocity (MPV), maximum velocity (Vmax), and power were measured during a single bench press set at different loads (90% and 100% of 1RM) and tempos. After the bench press set, Maximal isometric force (MIF), rate of force development (RFD), impulse, variability, and maximal average force (MAF) were obtained through an isometric bench press test. Results: Slower and faster tempos were not different in concentric performance than a normative tempo at the 90% 1RM load. A faster tempo generated higher MPV and Vmax than a normative one at the 100% 1RM load. A normative tempo produced higher MIF than a slower tempo, and higher impulse than a faster tempo after a 90% 1RM bench press set. Conclusions: PP athletes seem to have an optimized technique in submaximal loads; however, they may need faster eccentric velocities in the 100% 1RM load to improve their concentric performance.

Physiologia doi: 10.3390/physiologia6020024

Authors: Cássia Daniele Zaleski Trindade Cláudia Dornelles Schneider Rodrigo Zacca Sofia Monteiro Ricardo J. Fernandes Flávio Antônio de Souza Castro

Excess post-exercise oxygen consumption (EPOC) reflects cardiorespiratory fitness, energy metabolism and the residual physiological effects of preceding exercise. We aimed to compare EPOC profiles of master swimmers across different age groups and performance levels. Fourteen male master swimmers performed a 200 m all-out front crawl and breath-by-breath gas exchange and their heart rates were recorded during exercise and for 5 min post-exercise. A single exponential regression model was fitted to the post-exercise oxygen uptake kinetics to determine the EPOC amplitude, time constant and time delay. The EPOC magnitude was calculated as the area under the oxygen uptake–time curve. Swimmers were grouped into younger vs. older and faster vs. slower clusters using the 50th percentile, and the associations between age, performance and physiological variables were examined. Older swimmers were slower and showed a lower peak oxygen uptake than their younger counterparts (213.9 ± 27.9 vs. 165.7 ± 24.9 s and 39.1 ± 4.8 vs. 50.2 ± 8.1 mL∙kg−1∙min−1; p < 0.05). Slower swimmers were older and displayed a lower EPOC amplitude than faster performers (69.8 ± 7.3 vs. 45.7 ± 1.7 years and 23.2 ± 4.0 vs. 36.8 ± 10.2 mL∙kg−1∙min−1; p < 0.05). Although many of the variables did not differ between groups, effect sizes were moderate to very large (except for time constant and time delay). The swimmers’ age related directly to their performance and inversely to their peak oxygen uptake, peak heart rate and EPOC amplitude, while performance presented inverse associations with peak oxygen uptake, peak heart rate, EPOC amplitude and EPOC magnitude (p < 0.05). Master swimmers of different ages and performance levels exhibited distinct EPOC characteristics, which may provide relevant information regarding the individualisation of training and recovery strategies in this population.

Physiologia doi: 10.3390/physiologia6020023

Authors: Anna Kurkiewicz-Piotrowska Agata Sylwia Budziak Kornelia Patla-Rymar Patrycja Luzarowska Olga Czerwińska-Ledwig Agata Szlachetka Adrianna Dzidek Magdalena Bartnicka Agnieszka Kulawik-Pióro

Objectives: The study aimed to comprehensively assess the impact of tattoos on the structural and functional properties of the skin in healthy women. Methods: The investigation included 22 female participants aged 19–41 years, covering a total of 88 tattoos. Various diagnostic tools were employed: a Tewameter TM300 to evaluate transepidermal water loss (TEWL), a Corneometer and Cutometer to measure skin hydration, elasticity, and firmness, and high-frequency ultrasonography (HFUS) to assess epidermal thickness and skin echogenicity. The results showed that the presence of tattoos did not significantly influence TEWL values. Although regional differences in TEWL were observed in non-tattooed skin, tattooed skin showed no such variability, suggesting a consistent barrier function regardless of tattoo location. Corneometric and cutometric assessments revealed no significant differences in hydration, elasticity, or firmness between tattooed and non-tattooed skin. These parameters were also not influenced by tattoo age, although a physiological decline in mechanical skin properties was observed with increasing participant age. HFUS indicated a significantly thinner epidermis in tattooed areas compared to their non-tattooed counterparts. Additionally, tattooed skin demonstrated a higher percentage of low-echogenicity pixels in the lower dermis, suggesting localized structural changes. However, neither the age of the tattoo nor the age of the participant significantly affected the ultrasound parameters. Conclusions: Tattoos did not impair key skin functions such as hydration, elasticity, or barrier integrity, but were associated with structural changes observable via high-frequency ultrasonography.

Physiologia doi: 10.3390/physiologia6020022

Authors: Sadeka Tamanna Mohammad Iftekhar Ullah Ridwan Iftekhar Latifa Shamsuddin

Menopause is a natural biological transition marked by the cessation of regular menstrual cycles and is associated with significant endocrine, hormonal, and metabolic changes. Sleep disturbances are among the most common and distressing symptoms during this period, affecting approximately 40–60% of women in the menopausal transition and postmenopause. Vasomotor symptoms, including hot flushes and night sweats, often occur alongside fatigue, anxiety, and mood disturbances. These symptoms frequently coexist with sleep disorders such as insomnia, early morning awakenings, fragmented sleep, obstructive sleep apnea, restless legs syndrome, and circadian rhythm disruptions. Evidence from animal models, translational research, and clinical studies highlights the complex interaction between hormonal fluctuations, neuroendocrine dysregulation, metabolic changes, and circadian rhythm disruption. These factors contribute to altered sleep regulation, appetite control, and weight gain during the menopausal transition. This review summarizes current evidence on the mechanisms of underlying sleep disturbances in menopause, their clinical manifestations, diagnostic approaches, and available therapeutic strategies. Improving the management of sleep disorders during this stage may substantially enhance overall health and quality of life in menopausal women. We discuss presentation of different sleep disorders in menopause, their current management and future direction of research for development of precision-based algorithm of treatment considering the endocrine and hormonal profile of the women.

Physiologia doi: 10.3390/physiologia6010020

Authors: Rasha Abdeen Refaei Ahmed M. Refaat Amany M. Hamed Noha A. R. Fouda Zeyad Elsayed Eldeeb Mohana Rawia M. Ibrahim Ereen Kondos Naeem Gehad S. Mokhtar Pierre E. Mehanny Sherine Nabil Mohammed Fawzy Nagwa M. El-Sawi Elsayed Eldeeb Mehana Hamouda Nadia S. Mahrous

Background: Zearalenone (ZEA) is a potent estrogenic mycotoxin that adversely affects the female reproductive system, causing hormonal imbalance, uterine enlargement, structural changes in the reproductive tract, and reduced fertility. This study evaluated the protective effects of melittin-loaded chitosan nanoparticles (MEL-NPs) against ZEA-induced ovarian toxicity in female rats. Methods: Forty-eight adult female Wistar rats (180–200 g) were divided into four groups: Control, ZEA, ZEA + MEL, and ZEA + MEL-NPs. ZEA (2.7 mg/kg b.w.) was administered orally twice weekly for two weeks. MEL and MEL-NPs (40 μg/kg b.w.) were given orally three times weekly for one month. Serum biochemical parameters were measured, and ovarian tissues were examined grossly and histopathologically. qRT-PCR was performed to assess mRNA expression of inflammatory markers (TNF-α, IL-6, IL-1β), apoptotic marker (Caspase-3), and steroidogenic enzyme (CYP19A1). Results: ZEA exposure induced significant ovarian toxicity, evidenced by increased TNF-α, IL-6, IL-1β, LH, FSH, CA-125, and Caspase-3, along with decreased progesterone, antioxidant capacity, and CYP19A1 expression. Histopathology revealed ovarian atrophy, follicular degeneration, and fibrosis. Treatment with MEL-NPs markedly reversed these alterations, normalizing cytokine and hormonal profiles, restoring CYP19A1 expression, and improving ovarian morphology. MEL-NPs demonstrated superior protective effects compared to free MEL. Conclusions: MEL-NPs effectively ameliorate ZEA-induced ovarian toxicity by restoring hormonal balance, enhancing antioxidant defense, and reducing inflammation and apoptosis. These findings suggest that MEL-NPs could be a promising therapeutic strategy for preventing mycotoxin-induced ovarian dysfunction.

Physiologia doi: 10.3390/physiologia6010021

Authors: Rafael Mendes Amorim Larissa Quintão Guilherme Mariana de Santis Filgueiras Guilherme Pereira Saborosa Gabrielle Ferreira Pires Nathan de Oliveira Neumann Volker Scheer Luciano Bernardes Leite Pedro Forte Alexandra Malheiro Marcus Vinicius Lucio dos Santos Quaresma Helton de Sá Souza Ana Claudia Pelissari Kravchychyn

Background: Hydration and electrolyte strategies are critical in mountain ultra-endurance events, yet field-based evidence from trail races remains limited. This study examined the relationship between fluid intake, sodium consumption, and body mass changes in trail runners competing under real environmental conditions. Methods: A cross-sectional field study was conducted during La Misión Brasil 2024. Athletes of both sexes competing in the endurance race (35 km; EG: n = 15; age = 37.0 [29.5–46.0] years; 12 men and 3 women) and the ultra-endurance race (80 km; UEG: n = 13; age = 42.0 [37.0–46.0] years; 11 men and 2 women) were included in the study. Pre- and post-race body mass were assessed, and in-race fluid and food intake were collected using an adapted 24-h dietary recall. Water and sodium intake were expressed as total (L and mg, respectively) and per-hour (mL/h and mg/h, respectively) values. Environmental temperature and humidity were obtained from a local weather station. Group comparisons were performed using the Mann–Whitney U test, and associations were examined with Spearman’s correlation (p < 0.05). Results: EG (n = 15) and UEG (n = 13) showed similar absolute and relative body mass changes (2.6% to −3.0%; p > 0.05). EG runners presented greater weight loss rate (−270 vs. −115 g/h; p = 0.002), while UEG consumed higher total water (7.11 vs. 4.14 L; p = 0.008) and sodium (5789 vs. 2857 mg; p = 0.003). Water intake per hour was higher in EG (626 vs. 427 mL/h; p = 0.017). Body Mass Index was negatively correlated with hourly weight loss (r = −0.605; p < 0.001). Water and sodium intake per hour were positively correlated (r = 0.607; p < 0.001), though neither predicted hourly weight loss. Conclusions: Hydration responses may differ according to environmental stress and pacing demands. Changes in body mass may not necessarily reflect hydration adequacy, suggesting a possible multifactorial nature of hydroelectrolyte balance during mountain endurance events.

Physiologia doi: 10.3390/physiologia6010019

Authors: Manoel J. Rios David B. Pyne Ricardo J. Fernandes

Quantifying oxidative, glycolytic, and phosphagen energy system contributions during exercise is challenging due to their simultaneous activation and reliance on indirect estimation. This narrative review critically examines the methodological foundations, assumptions, and practical implications of current approaches used to estimate energy system contributions during continuous and intermittent exercise, with the aim of clarifying how these methods shape the interpretation of bioenergetic responses. Oxidative contribution, primarily estimated through oxygen uptake (VO2) integration, typically exceeds (~75–88%) in continuous efforts longer than 6 min and can reach values above ~87% when exercise duration allows full development of VO2 kinetics, particularly in trained young adult cohorts. In contrast, supramaximal efforts shorter than 30–90 s involve markedly lower oxidative contribution, commonly below ~50% and as low as ~8–19%. Glycolytic contribution is inferred from net blood lactate concentration accumulation and increases with exercise intensity, ranging from ~3–5% in longer severe-intensity efforts to values up to ~60% during brief maximal tasks lasting 15–30 s. Phosphagen contribution is estimated using the fast component of post-exercise VO2 recovery or theoretical phosphocreatine breakdown models, and can reach ~39–48% in maximal efforts lasting 10–15 s, while declining to values below ~10% in prolonged exercise. Each method is shaped by exercise duration, intensity, structural format, and physiological assumptions, contributing to methodological heterogeneity and limiting direct comparability between studies. Advances in portable gas analyzers, near-infrared spectroscopy, and biosensing technologies have improved temporal resolution and ecological validity. To enhance the accuracy and practical application of energy system profiling, standardized and integrative frameworks are urgently required.

Physiologia doi: 10.3390/physiologia6010018

Authors: Kawsar U. Chowdhury Kylie Tenhouse Abhinav Yenduri Subhrajit Bhattacharya Miranda N. Reed Vishnu Suppiramaniam

Background: Prenatal cannabinoid exposure (PCE) causes neurodevelopmental impairments affecting learning and memory; however, the receptor-level interactions underlying these cognitive deficits remain poorly understood. This study investigated whether a moderate dose of prenatal Δ9-tetrahydrocannabinol (THC) exposure alters the biophysical properties of synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, which are critical mediators of excitatory neurotransmission and synaptic plasticity. Methods: Pregnant Sprague-Dawley rats received a moderate dose (5 mg/kg) of THC or vehicle control via oral gavage throughout gestation and early postnatal development. Single-channel electrophysiological activity of the AMPA receptors (AMPARs) was recorded using patch-clamp techniques on synaptosomal AMPARs reconstituted into artificial lipid bilayers from adolescent offspring. Western blot analysis of GluA1- and GluA2-containing AMPAR subunits and the postsynaptic scaffold protein postsynaptic density 95 (PSD95) was conducted to assess protein levels. Results: Prenatal THC exposure decreased AMPAR open-channel probability, reduced mean open time, increased mean closed time, and altered burst channel activity significantly, without altering GluA1, GluA2, or PSD95 protein levels. Furthermore, the interactive channel-gating activity observed in control synaptosomes was absent in synaptosomes derived from THC-exposed offspring. Conclusions: Prenatal cannabinoid exposure induces early alterations in glutamatergic synaptic function primarily mediated by changes in AMPAR channel kinetics rather than receptor abundance. By identifying AMPAR single-channel dysfunction as a sensitive marker of PCE-induced synaptic disruption, this work provides a mechanistic framework linking prenatal THC exposure to long-term alterations in learning and memory.

Physiologia doi: 10.3390/physiologia6010017

Authors: Sara Spinelli Elisabetta Straface Lucrezia Gambardella Daniele Caruso Angela Marino Rossana Morabito Alessia Remigante

Introduction: cigarette smoking is a major source of systemic oxidative stress and a well-established risk factor for cardiovascular disease. Heated tobacco products (HTPs) are increasingly promoted as reduced-risk alternatives, yet their cellular effects remain incompletely understood. Methods: this study compared the oxidative stress-mediated effects of conventional cigarette smoking and HTP use on human erythrocytes. Erythrocytes from healthy non-smokers, conventional smokers, and HTP users were analyzed using biochemical, functional, and cytological approaches to assess redox status, membrane and cytoskeletal organization, anion exchanger 1 (AE1) function, antioxidant response, and redox-sensitive signaling pathways. Results: conventional smokers exhibited higher intracellular reactive oxygen species (ROS) levels, thiol depletion, methemoglobin and hemichrome formation, whereas HTP users showed marked lipid peroxidation despite lower ROS availability. Both groups instead displayed altered expression and distribution of key membrane and cytoskeletal proteins, including glycophorin A, AE1, spectrin, ankyrin, and band 4.1, indicating impaired membrane–cytoskeleton interactions. Functional analyses revealed an accelerated AE1-mediated anion exchange in erythrocytes from conventional smokers, whereas cells from HTP users exhibited a reduced sulfate accumulation, indicating altered transport capacity. In both groups, G6PDH activity was significantly increased, and redox-sensitive signaling pathways involving ERK, AKT, and eNOS were activated, accompanied by sex-dependent alterations in estrogen receptor expression and distribution. Conclusions: collectively, these findings identify erythrocytes as sensitive biomarkers of tobacco-related systemic damage and indicate that smoking-induced erythrocyte dysfunction, including that associated with HTP use, may actively contribute to vascular impairment. This evidence challenges the assumption that heated tobacco products confer a substantially reduced cardiovascular risk compared with conventional cigarettes.

Physiologia doi: 10.3390/physiologia6010016

Authors: Philip Buys Max E. Weston Emma L. Curtin Norita Gildea Mikel Egaña

Background/Objectives: Despite increasing interest in high-intensity exercise and cerebrovascular function, the effects of maximal sprint exercise on cerebrovascular reactivity (CVR), a key indicator of vascular health, remain unclear. Methods: This study investigated the acute effects of a 30-s all-out cycling sprint (Wingate Anaerobic Test, WAnT), on CVR to hypocapnia in 24 healthy young adults (12 males). Following familiarisation and a V˙O2max test, participants completed an experimental session where CVR was assessed at rest and 30 min post-WAnT. CVR was evaluated using a 1-min voluntary hyperventilation protocol (25 breaths·min−1), with middle cerebral artery blood velocity (MCAv) measured via transcranial Doppler ultrasound and end-tidal CO2 (PETCO2) recorded breath-by-breath. CVR was calculated as the absolute change in MCAv per 1 mmHg change in PETCO2 from the final 10 s of hyperventilation. Results: Resting MCAv and PETCO2 were significantly reduced post-WAnT (p < 0.01 and p < 0.001 respectively). Consequently, the reductions in MCAv and PETCO2 during hyperventilation were attenuated after exercise in both males and females (p < 0.01 and p < 0.001 respectively). Despite these changes, CVR remained unaltered in both sexes following WAnT (males: 1.79 ± 0.35 vs. 1.59 ± 0.26 cm·s−1·mmHg−1, p = 0.09; females: 2.01 ± 0.44 vs. 2.01 ± 0.46 cm·s−1·mmHg−1, p = 0.97). However, post-exercise CVR was significantly lower in males than females, despite no baseline sex differences (p = 0.01). Conclusions: Cerebrovascular reactivity to hypocapnia is preserved 30 min after a single bout of maximal sprint exercise in healthy young adults. Notably, females demonstrated a more favorable maintenance of CVR post-exercise compared to males, suggesting potential sex differences in CVR following maximal sprint exercise.

Physiologia doi: 10.3390/physiologia6010015

Authors: László Suszter Ferenc Ihász Zoltán Alföldi István Barthalos

Background: Anthropometric characteristics are known determinants of rowing performance, particularly during adolescence, when rapid physical growth affects strength, leverage, and movement efficiency. Understanding how body size and proportionality relate to rowing output is essential for contextualizing performance differences during youth rowing development. Objective: This study examined the associations between anthropometric variables and 2000 m ergometer performance in a multinational cohort of adolescent rowers, with separate analyses for males and females. Methods: A total of 126 youth rowers (65 males, 61 females) aged 14–16 years from eight countries participated. Standardized anthropometric measurements including body height, body mass, body fat (F%), relative muscle mass (M%), limb lengths, and body surface area (BSA) were assessed. Performance was assessed via maximal 2000 m ergometer testing, recording mean power output (W). Results: Significant anthropometric differences were observed between sexes. Performance outcomes mirrored these patterns: males produced substantially greater ergometer power (327.10 ± 48.65 W) compared to females (219.63 ± 30.96 W, p = 0.015). Across nations, anthropometric and performance means differed numerically but showed no statistically significant between-country differences (p > 0.05), despite small-to-moderate effect sizes. Correlation analyses revealed strong positive associations between ergometer power and body height (males: r = 0.70; females: r = 0.71), body mass (males: r = 0.75; females: r = 0.70), relative muscle mass (males: r = 0.62; females: r = 0.64) and body surface area (males: r = 0.78; females: r = 0.73). Relative fat mass showed a moderate-to-strong negative association with performance (males: r = −0.67; females: r = −0.64; p < 0.01). Conclusions: Anthropometric variables—particularly height, body mass, muscle mass, and body surface area—are strongly associated with rowing ergometer performance in adolescent athletes. These findings underscore the relevance of morphological profiling in youth rowing and provide descriptive insight into anthropometric–performance relationships during early junior rowing.

Physiologia doi: 10.3390/physiologia6010014

Authors: Mariano Costa Pires Fábio Yuzo Nakamura Diogo Vaz Leal Alberto Jorge Alves

Background/Objectives: Competitive karting places high physiological and cognitive demands on drivers. This field study investigated the acute effects of racing on heart rate variability (HRV), perceived fatigue and neuromuscular function, and cognitive-motor performance during an official event held under persistent rain. Methods: Longitudinal, repeated-measures design across two conditions: control (race video viewing) and competition (qualifying and race). Four drivers (Junior, X30 Senior, X30 Super Shifter) were assessed pre/post-control and post-qualifying/race on Day 1 (Saturday) and pre/post-race only on Day 2 (Sunday). Measures included continuous heart rate, pre/post HRV (HRV4Training; rMSSD, SDNN), perceived fatigue (ROF), bilateral handgrip strength, and visuomotor performance (reaction times and accuracy). Results: On Day 1, SDNN and rMSSD decreased significantly after qualifying versus pre- and post-control (p < 0.05), remaining globally lower post-race; no changes emerged in frequency-domain indexes. Perceived fatigue, handgrip strength, and mean/max reaction times did not change significantly; an improvement in minimum reaction time was observed post-race versus post-control (p = 0.033). rMSSD consistently decreased after racing on both days (p < 0.05) with no day × time interaction observed, and accuracy improved on Sunday, reflected by more correct attempts (hits) and fewer failed attempts (errors) (p < 0.05). Conclusions: Racing was associated with lower time-domain HRV indices (rMSSD/SDNN), consistent with heightened autonomic activation without measurable decrements in handgrip-based neuromuscular function or cognitive-motor performance. The improved accuracy on Day 2 may be related to an increased level of physiological activation and readiness associated with race day. Routine HRV monitoring across race weekends is recommended to guide recovery decisions when subjective scales show limited immediate sensitivity. These findings are preliminary due to the small and heterogeneous sample and should be interpreted cautiously.

Physiologia doi: 10.3390/physiologia6010013

Authors: Wankun Xie Min Zhao Shu-Huai Tsai Maxwell G. Su Luke B. Potts Natalia J. Rosa Travis W. Hein Lih Kuo Robert H. Rosa

Background/Objectives: The correlation between in vivo morphological and functional changes in the degenerating retina in a large animal model of retinitis pigmentosa (RP) has not been characterized longitudinally. Herein, spectral domain optical coherence tomography (SD-OCT) was used to monitor the dynamic morphological changes in the Pro23His rhodopsin transgenic (TgP23H) pig model of RP and was correlated with electroretinography (ERG) in the rapid, early phase of photoreceptor degeneration. Methods: TgP23H and wild-type (WT) hybrid pig littermates at the ages of postnatal days 30 (P30), P60, and P90 were studied. The thickness of different retinal layers was quantified using SD-OCT and compared with histology. Retinal function was evaluated with ERG at corresponding time points. Results: In the WT pigs, retinal morphology on SD-OCT was consistent throughout the observation period. In the TgP23H pigs, the retinal thickness decreased significantly from P30 to P90. Moreover, the relative intensity of the ellipsoid zone (EZ) progressively decreased, while the intensity of the interdigitation zone–retinal pigment epithelium (IZ-RPE) progressively increased during this period. Morphological changes in SD-OCT corresponded with histology, as well as the progressively decreased amplitude of the ERG photopic a- and b-waves in the TgP23H pigs. Conclusions: Retinal degeneration can be quantified using SD-OCT by measuring retinal thickness and the intensity of the EZ and IZ-RPE bands in the TgP23H pig. The SD-OCT results correspond with the histologic and ERG assessments of retinal degeneration. These data provide a foundation for future preclinical studies investigating potential new therapeutic strategies in a large animal model of retinitis pigmentosa.

Physiologia doi: 10.3390/physiologia6010012

Authors: Javier Cano-Sánchez María del Carmen Carcelén-Fraile Juan Miguel Muñoz-Perete

Background/Objectives: Cognitive impairment and sleep disturbances are highly prevalent in individuals with multiple sclerosis (MS), particularly during middle age, and negatively affect functional independence and quality of life. Although physical exercise has demonstrated cognitive and sleep-related benefits in MS, tolerance to high-intensity training is often limited. Blood flow restriction (BFR) training, which combines low-load resistance exercise with partial vascular occlusion, has emerged as a feasible alternative. This study aimed to evaluate the effects of a 12-week BFR training program on performance in specific cognitive domains and sleep quality in middle-aged adults with MS. Methods: A randomized controlled trial was conducted in 65 adults with relapsing–remitting multiple sclerosis (RRMS) aged 40–65 years and an Expanded Disability Status Scale score below 7. Participants were randomly assigned to a BFR training group or a usual-care control group. The intervention consisted of supervised low-load resistance training with BFR performed twice weekly for 12 weeks. Outcomes assessed before and after the intervention included processing speed (Symbol Digit Modalities Test), executive function (Trail Making Test A and B), verbal fluency (Isaacs Set Test), and self-reported sleep quality (Pittsburgh Sleep Quality Index). Results: Compared with controls, participants in the BFR group showed significant improvements in specific cognitive domains, including processing speed, executive function, and verbal fluency. Significant reductions were also observed in self-reported global sleep disturbance and daytime dysfunction. No adverse events were reported. Conclusions: A 12-week BFR training program improved performance in key cognitive domains and self-reported sleep quality in middle-aged adults with MS, supporting its feasibility and potential clinical relevance as an exercise-based intervention.

Physiologia doi: 10.3390/physiologia6010011

Authors: Szymon Kuliś Wiktor Kłobuchowski Bianca Callegari Givago Silva Souza Kajetan Ornowski Adam Maszczyk Jan Gajewski Przemysław Pietraszewski

This meta-analysis investigates the acute (immediate) pre–post changes in the modulation of physiological tremor in healthy adults following physical exercise, including resistance-based protocols. Physiological tremor is characterized by low-amplitude, high-frequency oscillations during posture or movement and reflects transient changes in neuromuscular control. Background/Objectives: Quantify the pooled effect of physical exercise on physiological tremor amplitude in healthy adults using magnitude-based metrics (RMS, peak power). A secondary objective was to synthesize evidence from acute resistance-based protocols separately. Methods: This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines and followed the methodological framework outlined in the Cochrane Handbook for Systematic Reviews of Interventions. Thirteen experimental studies met the inclusion criteria, with eleven included in the general exercise analysis and eight in the acute resistance-based subset. Results: Random-effects models revealed a moderate reduction in tremor amplitude following acute exercise (Hedges’ g = −0.42, p < 0.001). The resistance-based synthesis was restricted to acute single-session protocols only and indicated a directionally consistent reduction in tremor amplitude. Conclusions: These findings suggest that physical exertion is associated with transient suppression of physiological tremor amplitude. Acute single-session resistance-based exercise protocols showed a consistent direction of effect, although pooled estimates should be interpreted cautiously due to heterogeneity. Overall, physiological tremor may serve as a sensitive, non-invasive outcome measure reflecting short-term neuromuscular state.

Physiologia doi: 10.3390/physiologia6010010

Authors: Estela Álvarez-Gallardo Andrea Calderón García María Isabel Ramírez-Goercke Pedro Belinchón-deMiguel Vicente Javier Clemente-Suárez

Background/Objectives: Teaching is a profession characterized by a high burden of stress. This study examined sex differences in autonomic regulation by analysing heart rate variability (HRV) and body fat percentage (BF%) in teachers, explicitly hypothesizing that the association between adiposity and autonomic modulation (HRV) would be more consistent in men. Methods: A cross-sectional study was conducted with 253 teachers from compulsory and university education during the 2022–2023 academic year. HRV was obtained from heart rate recordings, and body composition was assessed using bioelectrical impedance analysis. Analyses were stratified by sex and, in addition to comparisons based on the sex-specific median of fat mass (kg), ANCOVA models were performed and adjusted for age, teaching experience, and educational level. Results: Teachers with higher BF% were older (43.46 vs. 40.65 years; p = 0.007) and reported higher perceived stress (7.60 vs. 6.83; p = 0.034). In men, HRV was lower in the ≥p50 adiposity group, with reductions in RMSSD and pNN50 (p = 0.015–0.016). In women, RMSSD and pNN50 were not significant (p > 0.20; small effect sizes). In adjusted analyses (ANCOVA), no significant differences were found in men for any index; in women, HRmax and the LF/HF ratio were significant (small effects), whereas the remaining indices were not. Conclusions: Greater adiposity was associated with higher stress and lower HRV, particularly in men. In women, the pattern was more heterogeneous, and significance after adjustment was limited to HRmax and the LF/HF ratio, suggesting the need for sex-specific approaches to the assessment and promotion of psychophysiological well-being in teachers.

Physiologia doi: 10.3390/physiologia6010009

Authors: João Rocha João Serrano Pablo López-Sierra Jorge Arede Sergio J. Ibáñez

Background: This study examines how contextual factors influence the match load experienced by U14 athletes. Methods: Ninety-six male players from eight Portuguese regional selection teams were monitored during three official matches each, using WIMU Pro™ inertial devices with ultra-wideband (UWB) tracking systems. Fifteen internal and external load variables were analyzed, including player load/min, high-speed running (HSR), maximum heart rate (HRmax), and high impacts/min. Mixed linear models revealed significant inter-individual variability in all variables, showing sensitivity to match context. Results: Losing teams exhibited higher player load/min. Balanced matches provoked greater cardiovascular and locomotor demands, particularly in HRmax and HSR metrics. Cluster analysis identified three match typologies based on score margin. Team level was strongly associated with final outcomes and quarter performance, reinforcing the predictive value of intra-match consistency. In contrast, match type (score margin) showed limited correlation with team quality or load distribution. Conclusions: These findings demonstrate the multifactorial nature of match load in youth basketball, supporting the implementation of individualized, context-aware training and recovery strategies while guiding long-term athlete development.

Physiologia doi: 10.3390/physiologia6010008

Authors: Rodrigo Villaseca-Vicuña Pablo Merino-Muñoz Guillermo Cortes-Rocco Natalia Escobar Marcelo Muñoz Lara Rodrigo Yañez Sepúlveda Joel Barrera-Díaz Jorge Pérez-Contreras

Understanding how contextual variables shape differences in match demands in youth football is essential for optimising performance and player development. Objective: This study aimed to compare physical and competitive performance according to playing position, match location, match result, and opponent quality in the physical and competitive performance of U21 football players from a professional Chilean club. Methods: Twenty male U21 players (19.2 ± 1.2 years) were monitored during 11 official matches using 10 Hz GPS devices (WIMU Pro™) and post-match Rating of Perceived Exertion (RPE). Variables included total distance (TD), high-speed running (HSR > 20 km/h), metres per minute (MM), accelerations/decelerations (N°AC/N°DC > 3 m·s−2), player load (PL), and peak velocity (PV). Contextual variables were classified by playing position, home/away, win/loss, and opponent quality (higher vs. lower rank). Results: Significant between-group differences were found across all contextual factors (p < 0.05). Midfielders (MFs) covered greater TD and reported higher RPE, while full-backs (FBs) and wingers (WGs) reached higher HSR and PV. Away and lost matches showed greater RPE, PL, and N°AC/N°DC, alongside more goals conceded. Facing higher-ranked opponents increased RPE and HSR but reduced explosive actions. Conclusions: Physical performance in U21 football is strongly modulated by contextual factors. Coaches should adjust training load and tactical strategies according to match conditions and positional roles to optimise adaptation and competitive readiness in developmental categories.

Physiologia doi: 10.3390/physiologia6010007

Authors: Natalia Loghin-Oprea Dana Manda Sorina Violeta Schipor Ana Popescu Oana-Claudia Sima Ana-Maria Gheorghe Ana Valea Luminita Suveica Alexandra-Ioana Trandafir Veronica Cumpata Mara Carsote Nina Ionovici

Background: Irisin, a muscle-derived hormone, enhances the energy metabolism by activating the brown adipose tissue and acts as a bone-forming agent across the entire life span. No consistent clinical data in humans have been published so far to highlight if blood irisin as glucose/bone biomarker should be refined based on the vitamin D status (deficient or sufficient). Therefore, we aimed to objectively assess the level of irisin in female adults with abnormal and normal vitamin D status, as reflected by the level of 25-hydroxyvitamin (25OHD) in relationship with glucose and bone metabolic parameters. Methods: This pilot, prospective, exploratory study included eighty-nine menopausal women aged over 50. We excluded subjects with malignancies, bone and metabolic disorders, insulin treatment, and active endocrine disorders. Fasting profile included glycaemia, insulin, and glycated haemoglobin A1c (HbA1c). Then, 75 g oral glucose tolerance test (OGTT) included glycaemia and insulin assay after 60 and 120 min. Bone status involved bone turnover markers and central dual-energy X-ray absorptiometry providing bone mineral density (BMD) and trabecular bone score. Results: Eighty-nine subjects were included in the following two groups depending on 25OHD: vitamin D-deficient (VDD) group (N = 48; 25OHD < 30 ng/mL) and vitamin D-sufficient (VDS) group (N = 41; 25OHD ≥ 30 ng/mL). The two groups had similar age and menopausal period (62.29 ± 10.19 vs. 63.56 ± 8.16 years, respectively; 15.82 ± 9.55 vs. 16.11 ± 9.00 years, p > 0.5 for each). A statistically significant higher body mass index (BMI) was found in VDD vs. VDS group (32.25 ± 5.9 vs. 28.93 ± 4.97 kg/m2, p = 0.006). Circulating irisin was similar between the groups as follows: median (IQR) of 91.85 (44.76–121.76) vs. 71.17 (38.76–97.43) ng/mL, p = 0.506. Fasting profile and OGTT assays showed no between-group difference. Median HOMA-IR in VDD group pointed out insulin resistance of 2.67 (1.31–3.29). Lowest mean/median T-scores at DXA for both groups were consistent with osteopenia category, but they were confirmed at different central sites as follows: femoral neck in both groups [VDD versus VDS group: −1.1 (−1.20–−0.90) vs. −1.1 (−1.49–−0.91), p = 0.526, respectively], only at lumbar spine for VDS group (T-score of −1.18 ± 1.13). The correlations between irisin and the mentioned parameters displayed a different profile when the analysis was performed in the groups with different 25OHD levels. In VDD group, irisin levels statistically significantly correlated with serum phosphorus (r = −0.32, p = 0.022), osteocalcin (r = −0.293, p = 0.038), P1NP (r = −0.297, p = 0.04), HbA1c (r = 0.342, p = 0.014), and BMI (r = 0.408, p = 0.003). Conclusions: This pilot study brings awareness in the analysis of irisin in relationship with glucose and bone-related biomarkers correlates, showing a distinct type of association depending on 25OHD level, which might represent an important crossroad in the multitude of irisin-activated signal transduction pathways.

Physiologia doi: 10.3390/physiologia6010006

Authors: Michael Grün Kai Rothaus Martin Ziegler Alexander Beger Albrecht Lommatzsch Clemens Lange Henrik Faatz

Background: To investigate baseline MNV characteristics in Optical Coherence Tomography Angiography (OCTA) and its impact on therapeutic needs and visual acuity after 5 years in initially therapy-naïve eyes. Methods: A retrospective study of 43 therapy-naïve eyes with neovascular AMD (nAMD). OCTA was performed at baseline and all eyes were observed for 5 years. MNV architecture was characterized by area, total vessel length, flow density and fractal dimension. These variables were tested for correlation with the number of administered intravitreal injections (IVIs) and best-corrected visual outcome (BCVA) after 5 years of treatment. Results: Mean follow-up time was 4.97 ± 0.21 years. Area and total vessel length of MNVs were significantly associated with a higher number of administered IVIs after 5 years (p < 0.05), flow density significantly correlated with fewer IVIs (p < 0.05). Fractal dimension showed a tendency to more IVIs (p = 0.056) after 5 years. Flow density at baseline correlated with a better BCVA (p < 0.05). In contrast, MNV area size, total vessel length and fractal dimension did not show any correlation to BCVA after 5 years (p > 0.05). Conclusions: Specific features of MNV architecture such as area, total vessel length and flow density can predict long-term treatment requirement and visual outcome. Further studies using deep learning algorithms are necessary to explore the usage of these findings in daily practice.

Physiologia doi: 10.3390/physiologia6010005

Authors: Vianney Curiel-Cervantes

Resistance training (RT) influences endocrine pathways that control skeletal muscle (SM) growth. This review summarizes 25 years of evidence (January 2000–December 2025) from PubMed, Medline, and ScienceDirect, focusing on three aspects: (1) exercise types such as RT, speed, power, high-intensity interval training, and aerobic training at various intensities; (2) dietary factors, including caloric restriction, total protein, protein sources, amino acids, and carbohydrates; and (3) aging-related physiological factors that may impair the insulin/IGF-1 axis in SM, such as insulin resistance, fat infiltration, physical inactivity, mitochondrial dysfunction, and inflammation. The data from Grade A evidence in systematic reviews and RCTs are prioritized to develop practical recommendations and future research directions for young, middle-aged, older, and very old individuals. Evidence regarding the effects of anabolic amino acids in women, middle-aged, and very old individuals, as well as locally mediated IGF-1 effects of any type of exercise, is limited.

Physiologia doi: 10.3390/physiologia6010004

Authors: Christina Pagkaki Panagiotis Tsikouras Panagiotis Halvatsiotis

Background: Gestational diabetes mellitus (GDM) is a frequent pregnancy pathology with poor maternal and fetal outcomes and risk of type 2 diabetes in later life. Despite known risk factors, such as obesity, age, and familial history, new data suggest that environmental exposure to agents, such as pesticides, can play a role in the etiogenesis of GDM. Objective: The epidemiologic, experimental, and mechanistic evidence between pesticide exposure and GDM risk is summarized here, and we concentrate on recent research (2000–2025). Methods: We conducted a literature search in PubMed, Embase, and the Cochrane Library for studies published from January 2000 to December 2025 using combinations of the terms “fertilizers”, “herbicides”, and “pesticides” with “diabetes mellitus” and “gestational diabetes”. After deduplication, 12 unique studies met inclusion criteria for qualitative synthesis (GDM endpoint or pregnancy glycemia with pesticide exposure). Results: Occupational and agricultural exposure to pesticides during first pregnancy was determined to be associated with a significantly increased risk of GDM through various epidemiologic studies. New studies have implicated new classes of pesticides, including pyrethroids and neonicotinoids, with higher GDM risk with first-trimester exposure. Experimental studies suggest that pesticides provide potential endocrine-disrupting chemicals that can induce insulin resistance through disruption of hormonal signaling, oxidative stress, inflammation, β-cell toxicity, and epigenetic modifications. However, significant limitations exist. Most of the evidence is observational, measurement of exposure is often indirect, and confounding factors are difficult to exclude. Notably, low dietary and residential exposure is not well studied, and dose–response relationships are undefined. Conclusions: New data indicate that pesticide exposure during early pregnancy and occupational exposure may increase the risk of GDM. Prospective cohort studies using biomonitoring, chemical mixture exposure, and geographic variation in pesticide exposure should be the focus of future research. Due to potential public health implications, preventive strategies to ensure the quality of nutrition and to reduce maternal exposure to pesticides during pregnancy are rational.

Physiologia doi: 10.3390/physiologia6010003

Authors: Ryota Kobayashi Shotaro Seki Kun Niu Hideyuki Negoro

Background/Objectives: Arterial stiffness is an independent cardiovascular risk factor, and arterial velocity pulse index (AVI) and arterial pressure–volume index (API) are practical oscillometric markers. Shigin, a traditional Japanese vocal recitation practice characterised by abdominal breathing, has limited physiological evidence. This cross-sectional exploratory study examined the association between long-term shigin practice and arterial stiffness in older adults. Methods: Community-dwelling adults aged ≥60 years were classified into shigin practitioners (≥10 years), physically active non-practitioners, and inactive non-practitioners. AVI and API were measured using an upper-arm oscillometric device. Blood pressure, heart rate, salivary α-amylase (morning, standardised conditions), and peak expiratory flow were assessed. Results: Both shigin practitioners and active non-practitioners showed lower AVI and API, lower blood pressure, higher peak expiratory flow, and lower salivary α-amylase than inactive non-practitioners (p < 0.01). These associations remained significant after adjustment for blood pressure, heart rate, and sex. Conclusions: Long-term shigin practice was associated with arterial stiffness indices comparable to those of physically active older adults, without implying causality.

Physiologia doi: 10.3390/physiologia6010002

Authors: Peter Raidl Barbara Wessner Michael Methlagl Robert Csapo

Background: Regular exercise was previously shown to reduce glucocorticoid and cardiac-autonomic responses to psychosocial stressors. Specifically, laboratory-based stress induction procedures are recognized as valid experimental manipulations of the physiological stress response. Nevertheless, comparative research between different types of stressors is limited. This study was designed to examine the multi-system psychophysiological response to two stress-induction procedures—psychosocial (Trier Social Stress Test; TSST) and psychophysical (Maastricht Acute Stress Test; MAST)—in male and female athletes. Methods: In a crossover pilot study, 12 athletes (6 female) underwent a TSST and a MAST, one month apart. Saliva hormones and cardiac-autonomic response (heart rate and HRV) were analyzed, besides an untargeted proteomics analysis. Results: The MAST revealed a lower elevation of heart rate (SMD = −1.47 [−2.51, −0.43]) and reduction in RMSSD (SMD = 0.98 [0.01, 1.95]) compared to the TSST. No statistically significant differences were found for hormones or subjective stress (all p < 0.05). Sex comparisons of the area under the curve exposed overall lower responses in women for aldosterone (SMD = −1.50, [−2.45, −0.51]), cortisol (SMD = −1.35, [−2.28, −0.39]), cortisone (SMD = −1.43, [−2.38, −0.46]), overall glucocorticoids (SMD = −1.44, [−2.38, −0.46]), and stronger reduction in testosterone-to-cortisone (SMD = 1.41, [0.44, 2.35]). Interestingly, sex differences were more evident in response to the TSST. Conclusions: Found sex differences underscore the importance of sex sensitive research in stress and exercise science. Our data support the presented methodological approach and encourage properly powered research on stressor comparison in relation to sports and physical fitness.

Physiologia doi: 10.3390/physiologia6010001

Authors: Iris Prestanti Sofia Serafini Francesca Di Rocco Rosa Cavuto Andrea Fusco Pascal Izzicupo Angela Di Baldassarre

Background: Urinary incontinence (UI) is common in women and negatively affects quality of life. Although pelvic floor muscle training (PFMT) is effective, most studies have focused on isolated muscle contractions. Less is known about multimodal programs integrating posture, breathing, and intra-abdominal pressure management. This study examined how urinary loss (UL) and moderate physical activity (MPA), measured objectively, relate to perceived pelvic floor disorders after a five-week multimodal intervention. Methods: Twenty women (40–70 years) with UI participated in three weekly 60 min sessions for five weeks. Outcomes were assessed before and after the intervention: UL using the pad test, physical activity with a wrist-worn accelerometer, and pelvic floor disorders with the Pelvic Floor Distress Inventory (PFDI-20). Paired t-tests or Wilcoxon tests and regression models were used to analyze changes and associations between variables. Results: UL significantly decreased after treatment (p < 0.001) as did total PFDI-20 (p = 0.007). Before treatment, PFDI-20 was mainly predicted by MPA (β = −0.537, p = 0.013). After treatment, UL became the strongest predictor of PFDI-20 (β = 0.587, p = 0.008) while Δ analyses confirmed that changes in both UL (β = 0.444, p = 0.026) and MPA (β = −0.461, p = 0.021) predicted improvements in perceived pelvic floor disorders. Conclusions: A five-week multimodal program reduced UL and improved perceived pelvic floor disorders. After treatment, symptoms were more strongly related to UL than to MPA. This study suggests that a multimodal exercise approach may represent a feasible and potentially effective option for improving both objectively measured urinary loss and perceived pelvic floor symptoms.

Physiologia doi: 10.3390/physiologia5040057

Authors: George D. Dimitriadis Costas Chryssanthopoulos Anastassios Philippou Michael Koutsilieris

Physical inactivity, which currently dominates the lifestyles of most people, is linked to chronic metabolic diseases such as obesity, type 2 diabetes (T2D), hypertension, metabolic syndrome, and cardiovascular disease, all of which share insulin resistance as a common pathogenic mechanism. Both epidemiological and experimental intervention studies have consistently shown that physical activity and exercise can reduce the incidence of these diseases and significantly improve their clinical outcomes, resulting in enhanced quality of life and well-being. This approach includes various forms of aerobic and anaerobic/resistance training, either individually or in combination, leading to reduced insulin resistance and visceral fat, regardless of the weight loss achieved through diet. It also lowers inflammatory responses and oxidative stress, a harmful mechanism that leads to cellular damage, and positively impacts immunological regulation. Regarding timing, physical activity/exercise appears to produce better outcomes for metabolic control, particularly in individuals with T2D, when performed after dinner compared to other times of the day. In addition to organized physical activity/exercise sessions, practices such as interrupting prolonged sitting with frequent breaks every 30 min that involve muscular contractions and increased energy expenditure may also benefit metabolic health. Minimizing physical inactivity, prolonged sitting at work or during leisure time, can decrease the frequency of metabolic illness, enhance health and quality of life, and avert premature death. However, intense exercise may not always be the most beneficial option for health, and the relationship between adverse events and the intensity of physical activity or exercise resembles a U-shaped or J-shaped curve. Physical activity/exercise should be performed at a suitable intensity that aligns with personal capability. In this primarily clinically focused review, we discuss the effects of insulin on target tissues, the significance of insulin sensitivity in metabolic regulation, how physical inactivity contributes to insulin resistance, the different types of exercise and their impact on insulin effectiveness, and the importance of physical activity and exercise in managing metabolic diseases.

Physiologia doi: 10.3390/physiologia5040056

Authors: Alejandro Bustamante-Garrido Sebastián Sepúlveda González Felipe Inostroza-Ríos Otávio de Toledo Nóbrega Bianca Miarka Mauricio Araya-Ibacache Felipe J. Aidar Esteban Aedo-Muñoz Ciro José Brito

Background/Objectives: Understanding the factors that influence tendon mechanical properties is essential for optimizing performance and preventing injuries in elite athletes. This study aimed to identify the strongest correlates of the biomechanical properties (frequency, stiffness, logarithmic decrement, relaxation, and creep) in the Achilles and patellar tendons in elite international athletes. Methods: A cross-sectional study was conducted with 111 elite athletes from 11 sports disciplines assessed at a high-performance training center. Tendon properties were measured bilaterally using MyotonPRO. Anthropometric (height, weight, age), demographic (sex, limb dominance defined as the preferred limb for sport-specific activities), and sport-specific variables were analyzed using correlation, multiple regression, and machine learning approaches. Results: Height showed the strongest correlations with tendon frequency and stiffness, particularly for the Achilles tendon (r = 0.52 for frequency; r = 0.53 for stiffness; p ≤ 0.001, large effects). Sex differences were evident across all measures, with men showing higher stiffness and frequency, and women greater relaxation and creep (partial η2 = 0.35–0.48, Cohen’s d = 0.84–1.16). Sports discipline explained substantial variance in tendon properties (η2 > 0.40), and limb dominance influenced Achilles stiffness, with left-dominant athletes showing higher values (p < 0.05). Age showed minimal associations (r < 0.10). Conclusions: Height, sex, and sports discipline were the strongest correlates of Achilles and patellar tendon mechanical properties in elite athletes, with large and practically meaningful effects across sports. This comprehensive analysis, utilizing multivariate and machine learning approaches, provides insights that can inform individualized training, injury prevention, and performance optimization strategies in high-performance sports.

Physiologia doi: 10.3390/physiologia5040055

Authors: J. Howard Jaster Joshua Ong Giulia Ottaviani

This narrative review of rapid eye movement (REM) focuses on its primary etiology and how it fits into the larger framework of neurophysiology and general physiology. Arterial blood flow in the retina may be sensitive to the full overlying ‘weight’ of its adjacent and contiguous vitreous humor caused by the humoral mass effect in the Earth’s gravitational field. During waking hours of the day, this ‘weight’ is continuously shifted in position due to changing head position and eye movements associated with ordinary environmental observations. This reduces its impact on any one point on the retinal field. However, during sleep, the head may maintain a relatively constant position (often supine), and observational eye movements are minimal, leaving essentially one retinal area exposed at the ‘bottom’ of each eye, relative to gravity. During sleep, REM may provide a mechanism for frequently repositioning the retina with respect to the weight it incurs from its adjacent (overlying) vitreous humor. Our findings were consistent with the intermittent terrestrial nocturnal development of ‘gravitational ischemia’ in the retina, wherein the decreased blood flow is accompanied metabolically by decreased oxygen tension, a critically important metric, with a detrimental influence on nerve-related tissue generally. However, the natural mechanisms for releasing and resolving gravitational ischemia, which likely involve glymphatics and cerebrospinal fluid shifts, as well as REM, may gradually fail in old age. Concurrently associated with old age in some individuals is the deposition of alpha-synuclein and/or tau in the retina, together with similar deposition in the brain, and it is also associated with the development of Parkinson’s disease and/or Alzheimer’s disease, possibly as a maladaptive attempt to release and resolve gravitational ischemia. This suggests that a key metabolic parameter of Parkinson’s disease and Alzheimer’s disease may be a lack of oxygen in some neural tissues. There is some evidence that oxygen therapy (hyperbaric oxygen) may be an effective supplemental treatment. Many of the cardinal features of spaceflight-associated neuro-ocular syndrome (SANS) may potentially be explained as features of gravity opposition physiology, which becomes unopposed by gravity during spaceflight. Gravity opposition physiology may, in fact, create significant challenges for humans involved in long-duration space travel (long-term microgravity). Possible solutions may include the use of artificial gravitational fields in space, such as centrifuges.

Physiologia doi: 10.3390/physiologia5040054

Authors: Steven Vitti Meghan E. Smith Sean Killip Alyssa Sarkisov Grace Frattellone Craig Mattern Justin Faller

Purpose: We aimed to assess the effects of one-week betalain-rich beetroot concentrate (BRC) supplementation on high-intensity cycling performance in trained cyclists. Methods: Eighteen male (n = 15) and female (n = 3) cyclists (age: 38.83 ± 8.09; weight: 73.23 ± 10.95 kg; height: 176.86 ± 9.60 cm) were supplemented with a BRC or a placebo (PLA) for six days prior to the experimental trials. On the seventh day, a final dose was administered, and participants completed three all-out 15 s cycling sprints back-to-back, followed by a 4 km cycling time trial (TT). Physiological indicators related to performance were measured throughout the 4 km TT. Results: Sprint performance remained unchanged following PLA treatment. However, BRC treatment led to significant reductions in sprint performance during sprints 2 and 3 compared to sprint 1 (p < 0.05). Time trial performance did not differ between treatments (p > 0.05). Significant increases in physiological and psychological responses during the 4-km time trial were observed following both treatments (p < 0.05). However, heart rate was higher at 2 km compared to 1 km, the respiratory exchange ratio was slightly elevated at 2 km and 4 km relative to 1 km, and VO2 was slightly higher at 3 km and 4 km compared to pre-TT following BRC treatment only (p < 0.05). Conclusions: One week of a BRC does not enhance 4 km TT performance but may impair repeated-sprint performance in trained cyclists.

Physiologia doi: 10.3390/physiologia5040053

Authors: Amândio Dias Bruno Lopes Francisco Machado João Fonseca Ricardo Santos Rodrigo Alves

Background/Objectives: Hamstring injuries are highly prevalent in sports and often occur, particularly among recreational and professional athletes. Assessing eccentric hamstring strength is critical for injury prevention and rehabilitation, with isokinetic dynamometry being considered the gold standard. However, its accessibility is limited by cost and logistics. This study aimed to evaluate the validity and reliability of the My Jump Lab (version 4.0) mobile application in estimating eccentric peak torque in the break-point angle, compared with isokinetic dynamometry. Methods: Twenty-seven recreational athletes (twenty-six male, one female) were assessed bilaterally using the mobile application and isokinetic dynamometer, which is considered the gold standard for this type of strength assessment. Statistical analysis included Pearson’s correlation, intraclass correlation coefficient (ICC), standard error of measurement (SEM), coefficient of variation (CV), and Bland–Altman plots. Results: Results showed excellent inter-rater reliability (ICC = 0.999; CV = 0.66%) for both smartphone application evaluators and good comparative validity and reliability (ICC ≈ 0.76 with confidence interval: 0.5367–0.876; p < 0.001 and r ≈ 0.705;) when comparing with isokinetic dynamometry. Conclusions: My Jump Lab is a mobile application which can provide a practical and accessible mean for monitoring eccentric hamstring strength in field settings. The app may serve as a feasible field-based alternative to laboratory dynamometry for eccentric strength monitoring.

Physiologia doi: 10.3390/physiologia5040052

Authors: Manuel Jesús Rodríguez Chavarría Manuel Chavarrías-Olmedo Jorge Pérez-Gómez

Background/Objectives: Hypertension is a leading cause of cardiovascular morbidity and mortality, particularly in older adults, pharmacological therapy is effective, but side effects and limited adherence highlight the need for non-pharmacological alternatives. This study investigated the effects of a structured Bodypump (BoP) programme, a choreographed group-based resistance training intervention, on blood pressure (BP) and functional fitness in sedentary older adults with hypertension. Methods: Thirty-two participants (65.4 ± 7.7 years) diagnosed with hypertension were randomly allocated to a BoP group (n = 16) or a control group (CG) (n = 16). The intervention lasted 8-week and consisted of 3 supervised sessions per week. Resting systolic BP (SBP) and diastolic BP (DBP) were measured using a validated automated device (Omron M3 Intellisense, HEM-7051-E), functional capacity was assessed with the Senior Fitness Test (SFT) battery. Results: After the intervention, BoP exhibited significant reductions in SBP (−24.4 ± 4.7 mmHg; p < 0.001) and DBP (−6.4 ± 2.7 mmHg; p = 0.025) compared to CG. BoP improved functional fitness, lower- and upper-body strength, aerobic endurance and agility (p < 0.05), with no changes in the CG. Conclusions: 8-week of BoP programme reduced BP and enhanced physical function in sedentary hypertensive older adults. Given its accessible, motivating and socially engaging format, BoP represents a promising non-pharmacological strategy for hypertension management and functional fitness of healthy ageing.

Physiologia doi: 10.3390/physiologia5040051

Authors: Yoel Antoranz Manuel Ruiz Freire Carlos Mª Tejero-González

Background/Objectives: Osteoporosis is a global health issue characterized by decreased bone mineral density (BMD), which increases the risk of fractures in adulthood. Adolescence, particularly the pubertal stage, is a critical period for maximizing BMD, and physical activity is a key modifiable factor in this process. The aim of this study was to conduct a systematic review of physical exercise interventions aimed at improving BMD in adolescents. Methods: The PRISMA methodology was applied, with searches conducted in PubMed, Web of Science, and SPORTDiscus. Included studies involved participants aged 11 to 18 years, structured physical activity interventions, and valid methods for assessing bone quality. Studies that included supplementation, lacked sufficient intervention details, or had no comparison group were excluded. Results: A total of 1464 articles were identified, of which 17 met the inclusion criteria and were analyzed. The results suggest that strength training programs and impact activities (such as football, volleyball, plyometric exercises, or running) appear to show benefits for bone development compared to control groups or non-osteogenic activities. The combination of strength and impact may reduce the time required to achieve measurable improvements. Non-osteogenic activities such as swimming and cycling showed no benefits on their own but may be beneficial when combined with resistance or impact training. The qualitative analysis indicates a certain risk of bias across the studies included. Conclusions: Although available evidence indicates that exercise programs involving strength or impact activities of around 8 months in duration and with a frequency of three sessions per week can be beneficial, these recommendations should be interpreted with caution due to the heterogeneity and limited number of studies, as well as the low certainty of the evidence. The combination of strength and impact exercises seems to shorten the intervention time required to achieve measurable improvements to approximately 6 months. These interventions appear to be most effective during early and middle adolescence, but current data do not consistently support sex-related differences.

Physiologia doi: 10.3390/physiologia5040050

Authors: Alfredo Miranda-Martínez Erika Rodríguez-Martínez Pamela Barragán-Reséndiz Selva Rivas-Arancibia

Adipose tissue is an organ with a high metabolic rate, functioning as a storage site for potential energy derived from food. It is a heterogeneous tissue composed of various cell types that respond differently to stimuli. Polyunsaturated fatty acids are lipids characterized by the presence of multiple double bonds in their molecular structure. These fatty acids are particularly vulnerable to oxidation by Reactive Oxygen Species, a process known as lipoperoxidation. While the oxidized lipids can serve important physiological roles within adipose tissue, they can also enter the bloodstream, where they associate with lipoproteins, leading to cellular damage and increased systemic oxidative stress. In cases of obesity, adipose tissue displays an exaggerated inflammatory and immune response that can affect multiple body systems, contributing to the onset of chronic degenerative diseases. Therefore, adipose tissue is a complex organ in which metabolic, endocrine, and immune response processes are intricately regulated and coordinated. This paper explains the role of alterations in redox balance, lipogenic, and inflammatory functions in adipose tissue as important risk factors for the development of chronic degenerative diseases, including those affecting the central nervous system. For this study, we searched multiple databases, including PubMed, Scopus, Google Scholar, the Cochrane Library, and Medscape, from 2015 to the present.

Physiologia doi: 10.3390/physiologia5040049

Authors: Josh Landers Cody Walker John Teed Rian Mcfarlane Geoff Halversen

Oral health represents a complex interplay between local microbial ecology, host immune responses, and systemic physiology. Far from being an isolated entity, the oral cavity is the entry point of the gastrointestinal and respiratory tracts and harbors up to one trillion microorganisms. While commensal species maintain ecological balance, pathogenic bacteria such as Porphyromonas gingivalis drive inflammatory conditions like gingivitis and periodontitis. Studies suggest that as chronic inflammation persists and is manifested through sustained breakdown of periodontal tissues, systemic dissemination of oral pathogens contributes to bacteremia, endothelial dysfunction, and neuroinflammation. As a result, increasing evidence has been found linking these oral pathogens and inflammatory mediators to systemic conditions including Alzheimer’s disease, cardiovascular disease, and arthritis. This narrative review synthesizes current evidence linking oral health to systemic disease while addressing practical strategies to strengthen preventive care. Evidence-based interventions are presented as accessible tools for reducing both oral and systemic inflammatory burden. Importantly, this article emphasizes the public health imperative of bridging mechanistic insights with actionable oral hygiene practices. By promoting evidence-based strategies such as scaling and root planing, dietary sugar reduction, and judicious use of antimicrobial agents, individuals may reduce their risk of chronic inflammatory and degenerative diseases. Future interdisciplinary research is needed to clarify causal mechanisms and optimize preventive frameworks integrating oral-systemic health.

Physiologia doi: 10.3390/physiologia5040048

Authors: Olivian Savencu Horia-Dan Lișcu Nicolae Verga

The Systems Theory provides a valuable conceptual framework for analyzing biological complexity, particularly in oncology, where the multiple interactions between biological subsystems can influence tumor initiation, progression, and treatment response. This approach facilitates the integration of data derived from genomics, metabolomics, routine medical analyses, and the clinical examination of the patient, thus overcoming the limitations of the reductionist model. By applying the principles of living systems, new tumor vulnerabilities can be identified, as well as models of cellular, metabolic, and informational organization. The use of systems theory in oncology may contribute to the development of personalized and precision medicine, improving diagnostic and prognostic methods, and enhancing the efficiency of personalized therapies with the aim of improving therapeutic outcomes and the patient’s quality of life.

Physiologia doi: 10.3390/physiologia5040047

Authors: Bianca Rossi Botim Bruna Cabugueira Kariny Realino Ferreira Thaís Carvalho Oliveira Michelle Almeida Barbosa Gabriela Lopes Gama Alexandre Carvalho Barbosa

Background/Objectives: Tinnitus lateralization, a perceptual characteristic often neglected in clinical assessment, may reflect underlying auditory plasticity. This study aimed to investigate whether changes in tinnitus lateralization following a multimodal neuromodulation protocol are associated with improved clinical outcomes, particularly regarding tinnitus severity and discomfort. Methods: A retrospective interventional study was conducted with 104 adults diagnosed with chronic tinnitus. All participants underwent a combined protocol involving transcutaneous auricular vagus nerve stimulation (taVNS), cervical transcutaneous electrical nerve stimulation (TENS), and photobiomodulation (PBM) targeting auditory pathways. Clinical assessments included the Tinnitus Handicap Inventory (THI), Visual Analog Scales (VAS) for loudness and discomfort, and lateralization reports before and after treatment. Lateralization patterns were categorized and compared using ANOVA and Kruskal–Wallis tests. Linear models explored demographic and clinical predictors of symptom change. Results: Substantial changes in lateralization were observed post-treatment. Participants who shifted from bilateral to unilateral tinnitus or from unilateral to non-perception showed the greatest symptom reductions (p < 0.001). The Bilateral → Unilateral group presented the most marked THI reduction (−20.82 ± 7.12), while minimal changes were observed in the Bilateral → Bilateral group. Loudness and discomfort improvements followed similar trends. No significant influence of age or sex on clinical response was identified, whereas longer tinnitus duration showed a modest positive association with symptom improvement. Conclusions: Perceptual reorganization of tinnitus lateralization may serve as a clinical marker of response to neuromodulation. Tracking lateralization could provide a simple, cost-effective adjunct to outcome monitoring in tinnitus management.

Physiologia doi: 10.3390/physiologia5040046

Authors: Ben Jones Mohammadreza Jamalifard Mike Rogerson Javier Andreu-Perez Jay Perrett Ed Hope Lachlan Carpenter Tracy Lewis J. Patrick Neary Chris E. Cooper Sally Waterworth

Background: Sport-related concussion is common in rugby union, yet female players remain underrepresented in research. This study examined seasonal changes in cerebral oxygenation, cardiac function, and concussion symptomology in adult female rugby players, and explored acute physiological responses following a single documented concussion. Methods: A total of 29 adult females (19 amateur rugby, 10 control) completed pre-, mid-, and end-season assessments. Measures included functional near-infrared spectroscopy (fNIRS) of the pre-frontal cortex, seismocardiography (SCG)-derived cardiac timing indices, and Sport Concussion Assessment Tool 6 (SCAT6). Group and time effects were analysed using general linear models and statistical parametric mapping. Typical error (TE) and its 90% confidence intervals (90% CI) were used to determine meaningful changes post-concussion. Results: Rugby players reported more SCAT6 symptoms (number: p = 0.006, η2p = 0.23; severity: p = 0.020, η2p = 0.17). They also had shorter systolic time (p = 0.002, η2p = 0.19) and higher twist force values (p = 0.014, η2p= 0.21) than controls. fNIRS revealed higher right-hemisphere oxyhaemoglobin (ΔO2Hb) responses for both tasks (ps < 0.001, η2p = 0.77 and η2p = 0.80) and lower activation in specific prefrontal channels. No seasonal changes occurred in global oxygenation or frequency band activity. In the exploratory single-concussion case, symptomology, SCG twist force, ΔO2Hb, and cardiac band power exceeded TE and its 90% CI at 5 days post-injury. Conclusions: The multimodal approach detected stable group-level physiology alongside localised cortical and cardiac differences, and acute changes following concussion. While these results highlight the potential of combined fNIRS and SCG measures to capture physiological disturbances, the small sample size and single-concussion case necessitate cautious interpretation. Further validation in larger, longitudinal cohorts is required before any biomarker utility can be inferred.

Physiologia doi: 10.3390/physiologia5040045

Authors: Diego Fernández-Lázaro Jesús Seco-Calvo José María Izquierdo Juan Mielgo-Ayuso Enrique Roche Gema Santamaría

Background: A sexually active lifestyle is generally associated with positive effects on physical condition and health. However, engaging in sexual activity prior to a sports competition could affect athletic performance. This systematic review examines the current literature on the impact of pre-exercise sexual activity on sports performance, with particular attention paid to its effects on physiological, hormonal, cognitive, and perceptual markers. Method: Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically reviewed original studies published within the last 25 years. Eligible studies were randomized or non-randomized controlled design and indexed on PubMed, Scopus, Dialnet, and Cochrane. Additional sources were consulted including a network diagram with Connected Papers®. Two methodological quality scales, McMaster University Occupational Therapy Evidence-Based Practice Research Group and Physiotherapy Evidence Database (PEDro), were used. The study was registered in PROSPERO (#CRD42023426555). Results: A total of 244 records were identified through the search process, of which 7 studies met the inclusion criteria. The studies involved 117 (115 men) physically and sexually active subjects including 29 elite top athletes. When comparing the sexual activity condition/group (SexG) to abstinence (AbsG), significant (p < 0.05) decreases were observed in average speed and maximum strength. In contrast, non-significant trends towards improvement (p > 0.05) were observed in exercise capacity, reaction time, and muscular endurance. No significant changes (p > 0.05) were found in physiological and hormonal biomarkers and fatigue perception. However, perceived exertion was significantly higher (p < 0.05) in SexG compared to AbsG. Conclusions: Current evidence does not conclusively support the influence of pre-exercise sexual activity on sports performance, or physiological and hormonal biomarkers. However, it could contribute to increased perception of exercise intensity.

Physiologia doi: 10.3390/physiologia5040044

Authors: Chanaka N. Kahathuduwa Jessica Blume Chinnadurai Mani Chathurika S. Dhanasekara

Background/Objectives: Binaural beat audio has gained popularity as a non-invasive tool to promote relaxation and enhance cognitive performance, though empirical support has been inconsistent. We developed a novel algorithm integrating real-time electroencephalography (EEG) feedback to dynamically tailor binaural beats to induce relaxed brain states. This study aimed to examine the efficacy and feasibility of this algorithm in a clinical trial. Methods: In a randomized, double-blinded, sham-controlled crossover trial, 25 healthy adults completed two 30 min sessions (EEG-guided intervention versus sham). EEG (Fp1) was recorded using a consumer-grade single-electrode headset, with auditory stimulation adjusted in real time based on EEG data. Outcomes included EEG frequency profiles, stop signal reaction time (SSRT), and novelty encoding task performance. Results: The intervention rapidly reduced dominant EEG frequency in all participants, with 100% achieving <8 Hz and 96% achieving <4 Hz within median 7.4 and 9.0 min, respectively. Compared to the sham, the intervention was associated with an faster novelty encoding reaction time (p = 0.039, dz = −0.225) and trends towards improved SSRT (p = 0.098, dz = −0.209), increased boundary separation in stop trials (p = 0.065, dz = 0.350), and improved inhibitory drift rate (p = 0.067, dz = 0.452) within the limits of the exploratory nature of these findings. Twenty-four (96%) participants reached a target level of <4 Hz with the intervention, while none reached this level with the sham. Conclusions: Real-time EEG-guided binaural beats may rapidly induce low-frequency brain states while potentially preserving or enhancing aspects of executive function. These findings support the feasibility of personalized, closed-loop auditory entrainment for promoting “relaxed alertness.” The results are preliminary and hypothesis-generating, warranting larger, multi-channel EEG studies in ecologically valid contexts.

Physiologia doi: 10.3390/physiologia5040043

Authors: Derick A. Anglin Madison L. Mattingly Nicholas J. Kontos Michael D. Roberts

Recent enthusiasm has surrounded the homeostatic roles that polyamines have in a variety of cell types. Thus, the purpose of this exploratory in vitro study was to determine how spermidine (SPD), a polyamine commonly consumed as a nutritional supplement, affected general markers of cellular health and function in human primary epidermal keratinocytes. Commercial HEKa cells were seeded onto either six-well (transcriptomics and immunoblotting) or 96-well culture plates (viability, ATP, and JC-1 assays) and cultured to ~90+% confluency through complete growth media (CGM) changes every 48 h. Once cells reached this level of growth, treatments included either CGM + phosphate-buffered saline (PBS control, or CTL), CGM + 1 µM SPD, and CGM + 10 µM SPD for either 6 or 24 h depending upon the outcome being assessed. Cellular ATP levels were not significantly affected by 1 µM or 10 µM SPD treatments lasting 24 h. However, cell counts were 9% greater (p = 0.007) when comparing 24 h 10 µM versus CTL treatments indicating increased cell viability. Transcriptomic analyses indicated that 6 h treatments with 10 µM SPD significantly altered 162 transcripts versus non-treated CTL cells (65 up-regulated and 97 down-regulated, p < 0.01). Four pathways were predicted to be enriched based on differential gene expression including protein deubiquitination (GO:0016579), membrane lipid biosynthesis (GO:0046467), DNA metabolic process (GO:0006259), and cell cycle process (GO:0022402). Additionally, the HR gene (essential for keratinocyte hair follicle formation) was significantly up-regulated at the mRNA level with 6 h 10 µM SPD, and immunoblotting confirmed a 96% increase in protein levels with 24 h 10 µM SPD treatments, albeit this did not reach statistical significance (p = 0.102). Pan-keratin protein content was also 60% greater in the 1 µM and 10 µM 24 h treatments than CTL (p ≤ 0.029). Finally, although select markers of mitochondrial content and biogenesis were not significantly altered with 6 h and 24 h treatments, mitochondrial membrane potential (an aspect of mitochondrial function) was 84% greater with 24 h 1 µM versus CTL (p < 0.001). In conclusion, these preliminary screening experiments in unperturbed human keratinocytes suggest that exogenous SPD positively affects various aspects of homeostasis by stimulating transcriptomic and functional alterations (e.g., increased cell viability and enhanced keratinocyte protein levels).

Physiologia doi: 10.3390/physiologia5040042

Authors: Yoshinao Nagashima Kouichi Takamoto Makiko Hiraishi Etsuro Hori Kiyoshi Kataoka Hisao Nishijo

Background/Objectives: This study aimed to objectively assess fatigue levels using facial expressions. Methods: This study included 25 female nurses aged between 30 and 50 years. We compared their subjective and objective fatigue levels after a night shift, when accumulated fatigue was assumed, with those after a day off, when recovery was expected. Fatigue levels were subjectively assessed using questionnaires and were also quantified by the Visual Analog Scale (VAS). Objective evaluations included (1) the degree of eye-opening, (2) the maximum distance and speed of facial skin movement by tracking changes in coordinate values of facial markers on the skin during intentional smiling, and (3) analysis of high-frequency (HF) components and the low frequency-to-high frequency (LF/HF) ratio in heart rate variability (HRV). Results: After a night shift, compared to after a day off, subjective assessments of mental and physical fatigue in the questionnaires and VAS values of own fatigue were significantly elevated. Concurrently, objective evaluations revealed that the degree of eye-opening, along with the maximum movement distance and speed of the lower eyelid, cheek, and mouth corners during intentional smiling, were significantly reduced. Furthermore, the HF component, an index of parasympathetic activity, significantly decreased, whereas the LF/HF ratio, an index of sympathetic activity, significantly increased. Additionally, significant correlations were observed between subjective VAS estimation of fatigue levels and each objective parameter examined. Conclusions: Measuring facial parameters is an effective method for objectively assessing facial expressions of fatigue, and these changes are mediated through reduced parasympathetic nervous activity and increased sympathetic nervous activity during fatigue.

Physiologia doi: 10.3390/physiologia5040041

Authors: Tereza Hladíková Iveta Štolhoferová Daniel Frynta Eva Landová

Background: The study of psychophysiological responses to disgust-evoking stimuli has long been neglected in favour of other emotional stimuli, especially those evoking fear. While the basic cascade of responses to a frightening stimulus is relatively well-understood, psychophysiological responses to disgust-related threats, such as parasites or rotten food, are scarcely studied. Methods: Here, we aimed to assess skin resistance (SR) change as a measure of electrodermal response to visual cues that signal the presence of disgust-relevant threats. To this aim, we recruited 123 participants and presented them with one of the following varieties of disgust-relevant threats: disgust-evoking animals (e.g., parasites, worms), spoiled food, threat of pandemic, or pollution and toxicity. The latter two represented modern threats to test whether also these modern stimuli can initiate immediate automatic reaction. Results: We found significant differences between the categories: Participants responded with the highest probability to disgust-evoking animals (38%) and sneezing (52%), suggesting that only ancestral cues of pathogen disgust trigger automatic physiological response. Moreover, we found significant inter-sexual differences: women exhibited more SR change responses than men, and the amplitude of these responses was overall larger. Finally, we report a weak effect of subjectively perceived disgust intensity on reactivity to threat stimuli. Conclusions: We discuss heterogeneity of disgust-relevant threats, their adequate behavioural responses, and subsequent heterogeneity of respective SR responses. We conclude that large interindividual variability might eclipse systematic differences between participants with high or low sensitivity to disgust, and that subjectively perceived intensity of disgust is only a weak predictor of electrodermal response to its elicitor.

Physiologia doi: 10.3390/physiologia5040040

Authors: Naiara Ribeiro Almeida Diego Alves dos Santos Kaio Lages dos Santos Diego Ignácio Valenzuela Pérez Felipe J. Aidar Walesca Agda Silva Miranda Bianca Miarka Andreia Cristiane Carrenho Queiroz Ciro José Brito

Aims: The present study evaluated the acute morning effect of melatonin supplementation (5 mg) on cardiometabolic responses. Methods: For this purpose, 12 physically active men (22.1 ± 1.3 years; 1.7 ± 01 m; 74.7 ± 12.1 kg; 24.3 ± 2.7 m/kg2; VO2max: 46.9 ± 2.3 mL/kg/min; 17.3 ± 5.2%F) were measured in a double-blind crossover protocol, where participants were measured before, during, and after a high-intensity interval exercise (HIIE) protocol [4 × 4 min at 95% of maximum heart rate (HRmax) with a 3 min interval at 60–70% of HRmax] followed by 30 min of recovery. At rest, the following variables were measured: HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), lactate, and maximum oxygen consumption (VO2max). At the end of each stage and interval, VO2, respiratory exchange ratio (RER), and HR were measured. During recovery, VO2, VCO2, RER, SBP, DBP, and HR were measured. Results: Melatonin significantly enhanced recovery metabolism, as evidenced by increased VO2 at Interval 3 (+2.2 mL/kg/min, p = 0.03, d = 0.69) and 5 min postexercise (+2.4 mL/kg/min, p = 0.02, d = 0.81). The RER was higher during Sprint 4 (+0.08, p = 0.01, d = 0.84), indicating greater carbohydrate reliance. Cardiovascular recovery was also improved, with a reduced HR at 30 min (−5 bpm, p = 0.04, d = 0.66) and lower SBP at 15 min (−8 mmHg, p = 0.02, d = 0.75). Lactate concentration at 30 min was lower with melatonin (−0.7 mmol/L, p = 0.03, d = 0.72). No significant effects were observed at rest or during early exercise. Conclusions: Acute morning melatonin intake may amplify metabolic responses to HIIE while facilitating cardiometabolic recovery. This dual-phase action may benefit athletes aiming to optimize energy expenditure, fat metabolism, and recovery during early-day training.

Physiologia doi: 10.3390/physiologia5040039

Authors: Juliana Andrade Assis Lúcio Marques Vieira-Souza Diego Valenzuela Pérez Cristiano Diniz da Silva Carlos Fuentes Veliz Naiara Ribeiro Almeida Bianca Miarka Otávio Toledo Nóbrega Ciro José Brito

Background: The high-intensity demands of CrossFit induce respiratory muscle fatigue, potentially impairing performance via the metaboreflex. Respiratory muscle training (RMT) may mitigate this effect, but evidence in female athletes remains limited. Objective: We aimed to investigate the effects of RMT on sport-specific performance and maximal inspiratory pressure (PIMAX) in recreational female CrossFit practitioners. Design: We conducted a parallel-group randomized controlled trial. Setting: The study was conducted in a CrossFit-affiliated gym. Participants: We recruited twenty-nine recreational female practitioners (age: 30.3 ± 7.9 years) with ≥1 year of uninterrupted training who were free from respiratory diseases. Interventions: Participants were randomized to a CrossFit-only group (n = 14) or CrossFit + RMT group (n = 15). Both trained 5 days/week for 6 weeks; the RMT group additionally performed 30 inspiratory efforts at 50% of PIMAX, 5 days/week, with weekly load adjustment. Main Outcome Measures: Primary: Sport-specific performance (total repetitions in a 10-min AMRAP [As Many Rounds As Possible] test). Secondary: PIMAX (cmH2O). Measurements were taken pre- and post-intervention. Results: Baseline performance and PIMAX were similar between groups. After 6 weeks, the CrossFit + RMT group improved in performance more (Δ = +10.5 ± 10.7 reps, p = 0.03, ηp2 = 0.168) than the CrossFit-only group (Δ = +2.3 ± 8.1). PIMAX gains were also greater with RMT (Δ = +19.6 ± 8.4 cmH2O, p = 0.043, ηp2 = 0.148) vs. control (Δ = +10.1 ± 9.7). No adverse events occurred. Conclusions: Adding RMT to CrossFit training enhanced sport-specific performance and inspiratory strength in recreational female practitioners more than CrossFit alone. RMT appears to be a safe and effective complementary strategy for high-intensity functional training.

Physiologia doi: 10.3390/physiologia5040038

Authors: István Barthalos Zoltán Alföldi Imre Soós Anna Horváth Pápai Ádám Balog László Suszter Ferenc Ihász

Background: Rowing is a highly demanding endurance sport, requiring simultaneous work of approximately 70% of the body’s muscle mass and the combined contribution of aerobic and anaerobic energy systems. Objective: This study aimed to analyze the cardiorespiratory responses and performance characteristics of elite junior male and female rowers during maximal effort over 2000 m on a rowing ergometer. Methods: Fifteen junior rowers (six males aged 15–17 and nine females aged 15–18) participated in the study. Anthropometric data (body height, weight, and body surface area) were recorded. All participants performed a maximal 2000 m test on a Concept2 D-model ergometer. Throughout the test, oxygen uptake (VO2), carbon dioxide production (VCO2), heart rate, and ventilation parameters were continuously measured. Performance and physiological data were analyzed in three intensity zones, defined by ventilatory thresholds (VT1–VT3), as well as at peak exercise. Results: Significant anthropometric differences were observed between genders. In terms of performance, males completed the 2000 m test significantly faster than females (208.83 ± 87.66 s vs. 333.78 ± 97.51 s, p = 0.0253). Relative VO2 at peak exercise was higher in males (58.73 ± 5.25 mL·kg−1·min−1) than females (48.32 ± 6.09 mL·kg−1·min−1, p = 0.0046). In most cardiorespiratory parameters, males outperformed females significantly, except for heart rate and ventilatory equivalents. Ranking analysis revealed that higher VO2max values were generally associated with a better placement in both genders, though this relationship was not perfectly linear. Performance time was negatively correlated with VO2Peak (r = −0.8286; p < 0.001), rVO2Peak (r = −0.6781; p < 0.01), and O2PPeak (r = −0.7729; p < 0.01). Conclusions: The findings confirm significant gender differences in anthropometric and cardiorespiratory characteristics of elite junior rowers and reinforce VO2max as a key determinant of performance. Yet, deviations from a direct VO2max–rank correlation highlight the influence of tactical, psychological, and biomechanical factors. Future research should provide practical recommendations for monitoring performance and tailoring training to optimize adaptation and long-term athlete development.

Physiologia doi: 10.3390/physiologia5040037

Authors: Andrei-Ionuţ Negoiţă Bogdan Amuzescu Dan Florin Mihăilescu Cristina Bordea

Serotonin (5-hydroxytryptamine—5-HT) is an important neurotransmitter that exerts a remarkably large array of biological roles in the central nervous system and at the body level. It is involved in generating emotions, being a natural mood stabilizer; it reduces depression, anxiety, modulates sleep, and has many other effects. It is also involved in fetal and postnatal brain development. This variety of biological effects, particularly in the central nervous system, with influence on behavior and cognitive functions, relies on a large number of pre- and postsynaptic serotonin receptor (5-HTR) isoforms spread throughout the brain. They can be grouped in seven large families and include over 18 subtypes, identified based on gene sequences, expression patterns, and pharmacological responses. While in vertebrates these receptors have been properly characterized and described, their correspondents in invertebrates have been far less explored, despite the assumption that they may have similar properties to those described in vertebrates. This paper summarizes the current knowledge in several important areas that together define the entire scope of serotonin receptor research, with a particular emphasis on the role of serotonergic central pathways and circuitry in thermoregulation and correlations with neurologic and psychiatric pathology.

Physiologia doi: 10.3390/physiologia5040036

Authors: Teruo Kiyama

Intracellular oxidation–reduction (redox) potential is a key factor regulating various physiological phenomena in the cell. Monitoring this potential change is therefore important for understanding physiological homeostasis in cells. Herein, we propose a new approach for the real-time, non-invasive estimation of the redox potential impacting biological metabolism and reactive oxygen species generation. Enzymes, specifically oxidoreductases, play a crucial role in catalyzing redox reactions by facilitating the transfer of electrons and hydrogen atoms between molecules. The redox potential of substrates, such as nicotinamide adenine dinucleotide, is determined by the ratio of its oxidized and reduced forms, while that of enzymes, such as succinate dehydrogenase, is determined using the reference electrode in protein-film voltammetry. Although the standard hydrogen electrode potential is defined as zero under standard conditions, the electrode potential of a reversible hydrogen electrode changes according to the ratio of the hydrogen ions (H+) and hydrogen gas (H2) in the biological fluids, as a reference electrode. The pH is maintained at 7.4 ± 0.1 in the arterial blood and the H2 that produced by the gut microbiota is measured in the endo-tidal breath for clinical diagnosis. The H2 in the endo-tidal breath equilibrates arterial blood during gas exchange in the lungs, as well as in whole-body tissues, due to the systemic circulation. In this study, H2 can be measured in the environmental gas compared to the atmosphere, and may serve as a novel factor for redox potential changes in redox enzymes, impacting biological metabolism and reactive oxygen species generation.

Physiologia doi: 10.3390/physiologia5030035

Authors: Christopher R. Harnish Matthew E. Holman Michael L. Bruneau

Background/Objectives: Transdermal bicarbonate (TBC) or carnosine (TC) have been sold as a convenient ergogenic aid, though little evidence supports these claims. The purpose of this study was to investigate if TBC or TC would improve high-intensity endurance cycling. Methods: Data were collected remotely using Zwift online platform. Fifteen cyclists completed four trials comprising five 9.1 km laps: warm-up lap, three interval laps (3 × 900 m hills, and 3 × 300 m sprints), and a 9.1 km time trial (TT) lap. A familiarization (FAM) trial followed by three randomized trials using a TBC, TC, or placebo (PLAC) lotion were completed. Trial data were assessed using general linear models to compare differences between conditions across cycling trials (p < 0.05). Results: Mean ± SD. 60 min mean max power (MMP60) was 2.9 ± 0.9 W/kg and ranged from 1.3 to 4.1 W/kg for participants. Exercise trials were 89.8 ± 17.0 min long. Laps 2–4 were ridden at 86.4 ± 7.3% and hill climbs at 131.6 ± 21.1% of MMP60, while sprints averaged 83.2 ± 17.7% of 30 s mean max power (MMP30s) and the TT ridden at 95.4 ± 8.7% of 20 min mean max power (MMP20). FAM trials were significantly lower (p < 0.05) in all power output measures, except TC sprints, and no heart rate or rating of perceived exertion differences. Similarly, there were no statistical differences in performance between any condition trials or placebo trial, but TBC hill climb power was significantly higher (p = 0.038) than TC trials. Conclusions: There are no apparent ergogenic benefits from TBC or TC during high intensity cycling performance.

Physiologia doi: 10.3390/physiologia5030034

Authors: Masab Mansoor

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have instigated a paradigm shift in the management of cardiometabolic disease. Initially developed for glycemic control in type 2 diabetes, their therapeutic role has expanded dramatically following the demonstration of robust cardiovascular benefits in large-scale clinical trials. This review provides a comprehensive synthesis of the physiological mechanisms underlying the cardioprotective effects of GLP-1 RAs, moving beyond the clinical outcomes to explore the cellular and molecular pathways involved. This review systematically deconstructs the effects of this drug class on the vasculature, where they mitigate atherosclerosis by improving endothelial function, attenuating vascular inflammation and oxidative stress, and favorably modulating plaque composition. The review delves into the complex and controversial effects on the myocardium, addressing the debate over GLP-1 receptor expression and detailing the interplay of direct and indirect actions on cardiomyocyte metabolism, ion homeostasis, and fibrosis. A central focus is the differential impact of GLP-1 RAs on heart failure (HF) phenotypes, clarifying their established benefits in HF with preserved ejection fraction (HFpEF), largely through targeting obesity and inflammation, whilst their role in the setting of HF with reduced ejection fraction (HFrEF) remains to be definitively determined. By integrating evidence from landmark trials with cutting-edge mechanistic studies, this review illuminates how GLP-1 RAs exert their profound cardiovascular effects and identifies critical unanswered questions that will shape the future of cardiometabolic medicine.

Physiologia doi: 10.3390/physiologia5030033

Authors: Alejandro Caña-Pino Lucía Pesado-Fernández

Background: Falls are a leading cause of morbidity and loss of independence among older adults, and occupational therapy (OT) offers a unique, multidimensional approach to fall prevention. This systematic review evaluates the effectiveness of OT-based interventions for improving balance, mobility, functional performance, and psychological outcomes related to fall risk in older adults. Methods: This review followed PRISMA (2020) guidelines. A comprehensive search of PubMed, Scopus, Dialnet, and OTseeker was conducted from March to May 2025. The inclusion criteria targeted studies involving non-pharmacological, OT-led interventions in adults aged ≥65. Seventeen studies were selected, including randomized controlled trials, pilot studies, and quasi-experimental designs. The data extraction and quality appraisal were performed independently by two reviewers. Results: The included interventions varied among exercise-based programs (e.g., Tai Chi, Pilates), virtual reality training, home safety modifications, cognitive–behavioral therapy, and wearable technologies. Most of the studies reported significant improvements in postural balance, fear of falling, and functional independence. Environmental adaptations and educational strategies also yielded positive outcomes. However, a real-world fall incidence reduction was inconsistently reported, and the methodological heterogeneity limited the meta-analytic synthesis. Conclusions: Occupational therapy contributes significantly to fall prevention through multimodal, person-centered strategies that integrate physical, cognitive, and environmental components. Future research should aim to standardize the outcome measures, include high-risk populations, and assess the long-term efficacy and cost-effectiveness of OT-led programs.

Physiologia doi: 10.3390/physiologia5030032

Authors: Gabriel Siquier-Dameto Javier Gimeno-Beltrán Gilberto Bellia Pere Boadas-Vaello Enrique Verdú

Background/Objectives: This study investigates whether systemic ovalbumin–aluminum sensitization followed by cutaneous challenge induces thermal hyperalgesia and spinal cord gliosis in mice. Methods: Adult female ICR-CD1 mice received ovalbumin–aluminum salt solution intraperitoneally on days 0, 7 and 14, and subcutaneously with daily skin application via brush during days 15–21, 28–35 and 42–49. Control animals received saline. Plantar thermal hyperalgesia was assessed on days 21, 35 and 49. On day 49, tissues (dorsal skin, spinal cord, footpads) were harvested after perfusion and processed histologically to detect mast cells, astrocytes, microglia, afferent fibers and intraepidermal nerve profiles. Results: Ovalbumin-treated mice displayed thermal hyperalgesia, increased astrogliosis, and reactive microglia in the spinal cord, and expanded CGRP- and IB4-immunoreactive fiber areas. In footpads, CGRP-positive intraepidermal nerve profile density was elevated, and dorsal skin showed increased mast cell density compared to controls. Conclusions: Combined systemic and cutaneous ovalbumin–aluminum sensitization induces skin inflammation, spinal gliosis, and nociceptive fiber sprouting in both central and peripheral sites, which likely contribute to the observed thermal hyperalgesia.

Physiologia doi: 10.3390/physiologia5030031

Authors: Bárbara Teruel-Peña Piedad Gómez-Torres Sergio Galarreta-Aperte Nora Suleiman-Martos Isabel Prieto Manuel Ramírez-Sánchez Carmen M. Fernández-Martos Germán Domínguez-Vías

Background/Objectives: The voltage-gated potassium channels of the Kv4 family (Kv4.1, Kv4.2, Kv4.3) regulate neuronal excitability and synaptic integration. The dysregulation of these channels has been linked to neurodegenerative diseases, such as Alzheimer’s disease (AD), spinocerebellar ataxias, amyotrophic lateral sclerosis (ALS), prion diseases, and Parkinson’s disease (PD). Current evidence is scattered across diverse models, and a systematic synthesis is lacking. This review seeks to compile and analyze data on Kv4 channel alterations in neurodegeneration, focusing on genetic variants, functional changes, and phenotypic consequences. Methods: A systematic search was conducted for peer-reviewed studies, including human participants, human-derived cell models, and relevant animal models. Studies were considered eligible if they investigated Kv4.1–Kv4.3 (encoded by gene encoding the Kv4.1-Kv4.3 α-subunit of voltage-gated A-type potassium channels (KCND1-KCND3)) expression, function, or genetic variants, as well as associated auxiliary subunits such as DPP6 (dipeptidyl peptidase–like protein 6) and KChIP2 (Kv channel–interacting protein 2), in neurodegenerative diseases. Both observational and experimental designs were considered. Data extraction included disease type, model, Kv4 subunit, functional or genetic findings, and key outcomes. Risk of bias was assessed in all included studies. Results: Kv4 channels exhibit significant functional and expression changes in various neurodegenerative diseases. In AD and prionopathies, reduced Kv4.1- and Kv4.2-mediated currents contribute to neuronal hyperexcitability. In spinocerebellar ataxias, KCND3 mutations cause loss- or gain-of-function phenotypes in Kv4.3, disrupting cerebellar signaling. In models of ALS and PD, Kv4 dysfunction correlates with altered neuronal excitability and can be modulated pharmacologically. Subunit modulators such as DPP6 and KChIP2 influence channel function and could represent therapeutic targets. Conclusions: Kv4 channels are crucial for neuronal excitability in multiple neurodegenerative contexts. Dysregulation through genetic or pathological mechanisms contributes to functional deficits, highlighting Kv4 channels as promising targets for interventions aimed at restoring electrical homeostasis and mitigating early neuronal dysfunction.

Physiologia doi: 10.3390/physiologia5030030

Authors: Manuela Filipec Marinela Jadanec Đurin

During pregnancy, physiological adaptations occur in the respiratory and cardiovascular systems to support the increased metabolic needs of both mother and fetus. Key respiratory changes include mechanical adjustments of the chest wall and diaphragm to accommodate the growing uterus; decreases in functional residual capacity and its components—expiratory reserve volume and residual volume—with minimal or no change in total lung capacity; and an increase in minute ventilation. Major cardiovascular adaptations involve elevated cardiac output, stroke volume and heart rate, and decreased mean arterial pressure and systemic vascular resistance. During exercise in pregnancy, there is an increase in ventilation, alveolar diffusion, elevated oxygen consumption, greater carbon dioxide production and changes in respiratory volumes and capacities, as well as increases in cardiac output, stroke volume and heart rate. Understanding these normal physiological changes during pregnancy and exercise in pregnancy is essential for healthcare providers to develop and adapt exercise programs according to the gestational age and physical fitness level of the pregnant woman.

Physiologia doi: 10.3390/physiologia5030029

Authors: Jorge Armando Ramos-Frutos Diego Oliva Israel Miguel-Andres Didier Samayoa-Ochoa Jesús Salvador Jaime-Ferrer Luis Angel Ortiz-Lango Agustín Vidal Lesso

Background: Plantar pressure distribution is a valuable tool for studying how the ground reaction forces are transmitted from the feet to the body and for detecting abnormalities in foot biomechanics. Objectives: The objective of this study was to determine the effect of the foot type (normal foot, flatfoot, and cavus foot) on plantar pressure distribution in healthy Mexican men and women aged from 3 to 74 years. Methods: A database of the plantar pressure distribution under dynamic and static conditions for both feet was studied using descriptive statistics, regression analysis, and statistical factorial design. The database contained images of the soles of the feet and pressure distribution of 996 persons between 3 and 74 years old (53.9% females and 46.1% males). Two different conditions were evaluated; the first was in a static condition, and the second was during walking. The Chippaux–Smirak Index (CSI) was used to classify the type of feet. Results: In the left foot, a linear regression analysis of the soles of the feet shows that the prevalence of flatfoot (p-value = 3.45 × E−5) decreased with age, while the normal foot (p-value = 7.39 × E−5) increased. When people are standing (static), the hindfoot (55.64 ± 18.80%) presents more pressure than the forefoot (45.18 ± 19.50%), while in dynamic, the forefoot (55.95 ± 13.36%) supports more pressure than the hindfoot (44.05 ± 13.36%). Similar behavior occurs in the right foot. A statistical factorial design ANOVA shows that the plantar pressure in the forefoot and hindfoot regions is significantly different (p < 0.05). Conclusions: The prevalence of flatfoot decreased with age, while the proportion of normal foot type increased. Under static conditions, the hindfoot bore more load than the forefoot, whereas under dynamic conditions, the forefoot bore more load than the hindfoot. This research contributes to generating a comprehensive database of reference values of the plantar pressure of different foot types in a Mexican population; this will be useful to podiatrists, clinicians, and physiotherapists for the analysis or treatment of abnormal foot postures.

Physiologia doi: 10.3390/physiologia5030028

Authors: Pedro Henrique A. Reis Giovanna K. Jorge Edimar C. Pereira Lai Yu Tsun Thais M. Gascón Beatriz da C. A. Alves Glaucia L. da Veiga Samantha S. de Carvalho Renato G. Cerquinho Leça Vagner L. Lima Fernando L. A. Fonseca

Background: Several studies have established correlations between low serum levels of vitamin D and various pathologies, such as diabetes mellitus and its complications. However, few studies analyze its levels in matrices other than blood plasma, such as tears and saliva. In this study, we aimed to demonstrate the feasibility of using tears and saliva as alternative biological matrices for laboratory assessment of vitamin D and glucose concentration in individuals with type II diabetes mellitus and healthy individuals, using the electrochemiluminescence method. Methods: This study included volunteers with type II diabetes and healthy controls, excluding those with certain comorbidities or a BMI ≥ 40. Blood, tear, and saliva samples were taken after 3 h of fasting for biochemical analysis of fasting glucose and vitamin D. Statistical analysis was conducted using GraphPad Prism® 8.0—with Pearson and other tests to evaluate correlations—at a significance level of 5% and test power > 95%. Results: A negative correlation between serum vitamin D values and those found in saliva (p = 0.041) was found, as well as a positive correlation between serum glucose values and those found in tears (p = 0.0254). Conclusions: Tears and saliva samples can be used as proxies for venous blood samples in specific situations, such as studying blood glucose levels and vitamin D levels. However, expanding the sample size is essential to confirm the correlation and develop an accurate equation for estimating serum levels of these markers using these alternative matrices.

Physiologia doi: 10.3390/physiologia5030027

Authors: Luigi Di Lorenzo Andrea Esposito Nicola Pirraglia Chiara Capaldi Gianleno De Vita Carmine D’Avanzo

Background: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and acute respiratory failure (ARF) are leading causes of hospitalization and functional decline in Italy, posing a significant burden on the healthcare system. In 2024, new national guidelines mandated the use of Intensive Care Rehabilitation Units (ICRUs) within MDC4 to provide structured post-acute respiratory rehabilitation. Objective: This study aimed to evaluate functional outcomes in patients with AECOPD and ARF treated in a single ICRU, assessing the effectiveness of guideline-based rehabilitation protocols. Methods: A retrospective audit was conducted on patients admitted in 2024 to a dedicated ICRU. Functional outcomes were assessed using the Barthel Index, Six-Minute Walking Test (6MWT), and Rehabilitation Complexity Index (RCI-e13). Correlation analyses were performed to explore relationships between baseline status, rehabilitation progression, and discharge outcomes. Results: Thirty-six patients were included. Significant improvements were observed across all scales from admission to discharge. The Barthel Index showed a strong positive correlation between initial and final scores (r = 0.72), while the 6MWT indicated a similarly robust correlation (r = 0.73). Greater functional gains were noted among patients with lower baseline scores, especially in mobility. The RCI-e13 reflected decreased clinical complexity by discharge, with moderate correlations to baseline severity. Age moderately correlated with length of stay (r = 0.30), but not with outcome scores. Conclusions: The implementation of early, intensive rehabilitation in an ICRU setting—aligned with Italy’s 2024 national guidelines—led to measurable functional improvements in patients with AECOPD and ARF. These findings support the utility of structured outcome monitoring and reinforce the role of ICRUs in optimizing post-acute care pathways within respiratory rehabilitation services.

Physiologia doi: 10.3390/physiologia5030026

Authors: Daniele Pereira da Silva Araújo Pablo Augusto Garcia Agostinho Suene Franciele Nunes Chaves Rafael de Freitas Ferreira Juliana Souza Valente Claudia Eliza Patrocínio de Oliveira Osvaldo Costa Moreira

Introduction: Women’s futsal demands strength, agility, speed, and endurance, involving sprints, dribbling, and rapid directional changes. In this context, the hamstring/quadriceps (H/Q) strength ratio and bilateral muscle asymmetries are recognized as risk factors for lower limb injuries and may also impact athletic performance. Objective: This study aimed to analyze power output in two inertial flywheel resistance exercises and identify muscle imbalances in the lower limbs of female university futsal players. Methods: Twelve athletes (22.9 ± 2.3 years; 163 ± 6.8 cm; 60.9 ± 9.9 kg; 22.8 ± 3.1 kg/m2; ≥9 years of experience) participated in the study. They performed 2 sets of 8 unilateral knee flexion and extension repetitions per limb, following a warm-up of 20 bodyweight squats. Power output was assessed using a multi-joint isoinertial device (Physical Solutions, SP, Brazil). Data were analyzed using mean and standard deviation, with significance set at α = 0.05. Results: Eccentric power was significantly higher in both exercises and limbs (EJPD = 0.003; EJPE = 0.006; FJPD < 0.001; FJPE < 0.001). An imbalance in the H/Q ratio was observed: concentric right = 50.38% ± 14.67; left = 42.46% ± 9.24; eccentric right = 56.71% ± 15.56; left = 58.38% ± 21.06. The right limb showed a greater concentric imbalance (p = 0.016). Conclusions: Eccentric power was higher in both exercises without inter-limb differences. An H/Q imbalance was detected, with greater asymmetry in the right leg for concentric power. Coaches are encouraged to prioritize eccentric training to address these imbalances.

Physiologia doi: 10.3390/physiologia5030025

Authors: Dawid Koźlenia Mikołaj Boros Rafał Szafraniec

Background/Objectives: The aim of this study was to investigate the acute effect of isometric and plyometric combined activation prior to the endurance performance assessed with the 30-15 Intermittent Fitness Test (30-15 IFT) and cardiovascular parameters. Methods: In this crossover study the data of 14 elite female soccer players aged 22.1 ± 2.9 years were assessed. The conditioning activity (CA) consisted of three sets of five seconds of maximal mid-thigh pull (IMPT), and peak force was measured, and four countermovement jumps were performed. Contact time, jump height, and reactive strength index (RSI) were assessed. Ninety seconds of rest between the sets was performed. Then, 7 min after the CA, the 30-15 IFT was performed. Results: One-way repeated measures (RM) ANOVA showed that performance during the CA did not decrease; what is more, it improved in RSI (p < 0.01). Further, paired samples t-test showed that the performance in the IFT did not change, whereas training impulse (TRIMP) was increased after CA (p = 0.039, ES = 0.61), thus the Bayesian paired test yielded only anecdotal evidence in favor of the alternative hypothesis (BF10 = 1.92; error = 2%). Conclusions: The improvement in CA suggests potentiation rather than fatigue. However, the unchanged performance alongside a modest TRIMP increase should be interpreted with caution, as TRIMP alone provides a limited assessment of physiological cost. Therefore, while the applied protocol did not enhance endurance performance, further research using multiple physiological markers is needed to clarify its impact on internal load and overall efficacy.

Physiologia doi: 10.3390/physiologia5030024

Authors: Dayton J. Kelly Anastasia H. Nepotiuk Liana E. Brown

Purpose: To investigate whether mild hypohydration in lightweight rowers compromises rowing performance despite a two-hour rehydration window. Methods: Experienced varsity rowers [11 male (82.3 ± 26.2 kg, age = 21.3 ± 4.0 years, height = 184.7 ± 2.4 cm) and three female (62.1 ± 11.8 kg, 2.3 ± 4.2 years, 166.4 ± 16.2 cm)] performed a 2000 m rowing ergometer time trial and visuomotor battery twice: once euhydrated and once after mild dehydration. Weight loss (−1.68 ± 0.23% body mass reduction) was achieved through a combination of 12 h (abstinence) of fluid and food restriction and sauna exposure. Results: Participants were significantly slower on the 2000 m rowing trial in the hypohydration condition than in the euhydration condition (+2.44 ± 4.5 s, p < 0.05). Hierarchical linear regression analyses revealed that this rowing performance decrement was explained by hypohydration achieved overnight through fluid abstinence (r2 = 0.504, p < 0.01) but not by hypohydration achieved in the sauna (r2 = 0.025, n.s.), corroborating our previous finding. This analysis also revealed a relationship between hypohydration-related rowing performance decrements and hypohydration-related changes in visuomotor function (r2 = 0.310, p < 0.01). Conclusions: These findings suggest that rowing time trial performance can be negatively affected by relatively small changes in hydration status and that the method by which hypohydration is achieved is important. Rowing performance losses were explained by hypohydration due to prolonged fluid abstinence and by hypohydration-related changes to neural control of movement. Performance losses were not related to rapid sauna-based fluid loss.

Physiologia doi: 10.3390/physiologia5030023

Authors: Rafael Luiz Mesquita Souza Felipe J. Aidar Leonardo dos Santos Jymmys Lopes dos Santos Lúcio Marques Vieira Souza Andre Luiz Gomes Carneiro Paulo Francisco de Almeida-Neto Breno Guilherme de Araújo Tinoco Cabral Anderson Carlos Marçal Pantelis T. Nikolaidis

Background/Objectives: In powerlifting, velocity indicators and skin temperature have been utilized to control training loads for both conventional athletes and athletes with disabilities. Therefore, the present study evaluated maximum velocity (Vmax), mean propulsive velocity (MPV), power (POWER) output, and skin temperature (ST) following a 5 × 5 training session at 80% of one-repetition maximum (1RM) in conventional powerlifters (CP) and paralympic powerlifters (PP). Methods: A total of 24 male athletes (12 CP and 12 PP) underwent a 5 × 5 training session at 80% 1RM. Post-session, velocity indicators, power output, and ST were assessed at 45% 1RM. Results: Only the CP group exhibited significant differences in Vmax (p < 0.015), MPV (p < 0.007), and power output (p < 0.022) between time points. Regarding ST, only the PP group showed differences (p < 0.004) in the sternal portion of the pectoral major. For the long head of the triceps brachii, differences were observed between groups in the post-session measurement (p > 0.024) and for the PP group only in the post-session measurement (p < 0.002). Conclusion: This study demonstrated that in following a traditional training session (80% 1RM), assessments at 45% 1RM revealed different effects in velocity, power output, and ST measures between CP and PP groups. These findings suggest that within the same sport discipline, training variables may have distinct impacts across different categories of athletes, and further research is needed to evaluate these different responses.

Physiologia doi: 10.3390/physiologia5030022

Authors: Amanda dos Reis Cota Édison Andrés Pérez Bedoya Pablo Augusto Garcia Agostinho Luciano Bernardes Leite André Schneider Pedro Forte António M. Monteiro Luís Branquinho José E. Teixeira Claudia Eliza Patrocínio de Oliveira Osvaldo Costa Moreira Miguel Araújo Carneiro-Júnior

Background/Objectives: Executive function, which includes inhibitory control, working memory, and cognitive flexibility, tends to decline with aging. While traditional resistance training (TRT) has shown positive effects in mitigating these declines, limited evidence is available regarding flywheel resistance training (FRT). This study aimed to evaluate and compare the effects of TRT and FRT on executive function in older women. Methods: In this randomized controlled trial (clinicaltrials.gov NCT05910632), 29 older women were allocated into two groups: TRT (n = 15) and FRT (n = 14). The intervention lasted eight weeks with two weekly sessions conducted at the Federal University of Viçosa. The TRT group performed exercises using machines and free weights, while the FRT group used a multi-leg isoinertial device. Executive function was assessed using the Victoria Stroop Test (inhibitory control), Digit Span Test (working memory), and Trail Making Tests A and B (cognitive flexibility). Data were analyzed using a Multivariate Analysis of Covariance (p < 0.05). Results: No significant changes were observed in inhibitory control (p = 0.350). Working memory improved significantly within both groups in forward (p = 0.002) and backward (p = 0.002) span tasks. For cognitive flexibility, Trail Making Test A showed no significant changes (p > 0.05), but Test B showed significant within-group (p = 0.030) and between-group (p = 0.020) improvements. The B-A difference was also significant (p = 0.040). Conclusions: Both resistance training modalities enhanced working memory and cognitive flexibility. However, FRT produced greater improvements in cognitive flexibility, suggesting potential advantages in cognitive aging interventions.

Physiologia doi: 10.3390/physiologia5030021

Authors: Gilvandro Oliveira Barros Felipe J. Aidar Raphael Fabricio de Souza Ciro José Brito Renato Méndez-delCanto Jymmys Lopes dos Santos Paulo Francisco Almeida-Neto Breno Guilherme de Araújo Tinoco Cabral Nuno Domingos Garrido Victor Machado Reis Rolland van den Tillaar Pantelis T. Nikolaidis

Objective: This study aimed to evaluate the effects of cold-water immersion (CWI) on post-training recovery in Kung Fu athletes. Methods: In a 3-week crossover design, 16 Kung Fu athletes (22.00 ± 5.95 years, 76.90 ± 9.74 kg) were divided into two conditions: CWI and passive recovery as a control (CON) measure. Through the study, muscle damage markers (creatine kinase [CK], lactate dehydrogenase [LDH], aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), physical performance tests (upper limbs power, SJ and CMJ), skin temperature (from lower and upper limbs), and skin temperature asymmetries were measured. Results: CWI resulted in a higher reduction of CK concentration than CON 24 h after the intervention (−21.32%; p < 0.001). The SJ height 24 h after the intervention was higher in the CWI than in the CON (p < 0.001). Both CWI and CON resulted in skin temperature returning to baseline levels 24 h after intervention. Conclusions: CWI was effective in restoring muscle power, reducing muscle damage and reducing body temperature (BT) in Kung Fu athletes. Cold water recovery showed better muscle power and strength 24 and 48 h after training when compared to the passive method. CK and skin temperature were better 24 h after cold water recovery.

Physiologia doi: 10.3390/physiologia5030020

Authors: Mateus Chaves Primo Ítalo Santiago Alves Viana Leonardo Silveira Goulart-Silva Wanderson Matheus Lopes Machado Luciano Bernardes Leite Pedro Forte Ricardo C. Calhelha António M. Monteiro Luís Branquinho Sandro Fernandes da Silva Claudia Eliza Patrocínio Oliveira Osvaldo Costa Moreira

Background/Objectives: Beetroot juice is a popular nutritional resource in sports due to its ergogenic effects, promoting vasodilation, hypotension, improved energy efficiency, and reduced oxygen cost. However, its role in modulating the autonomic nervous system during strength training remains understudied. This study assessed the effects of acute nitrate-rich beetroot juice supplementation on cardiovascular and hemodynamic responses to flywheel resistance exercise. Methods: Fifteen male participants (age 22 ± 3.64 years) from the Federal University of Viçosa completed a crossover, double-blind, placebo-controlled trial. Each participant consumed either 400 mg of standardized nitrate or a placebo before performing 4 sets of 8–12 repetitions at 100% of their maximum concentric strength using a leg extension exercise, with 90 s recovery intervals. Heart rate, blood pressure, oxygen saturation, and subjective perception of effort were measured after each set. Data were analyzed using SPSS 23, employing the Shapiro–Wilk normality test, t-test for related samples, and MANOVA with time and supplement factors. Results: NO3− supplementation led to a smaller increase in systolic blood pressure (SBP) during exercise compared to the placebo and reduced diastolic blood pressure (DBP) in the last set, reflecting decreased peripheral vascular resistance. However, no significant effects were observed for heart rate, rate–pressure product, oxygen saturation, time under tension, or subjective perception of effort. Conclusions: These findings suggest that NO3− supplementation can offer cardiovascular benefits by attenuating blood pressure increases during strength training, highlighting its potential as a low-risk ergogenic aid for healthy young men.

Physiologia doi: 10.3390/physiologia5030019

Authors: Catarina C. Santos Ana C. Kanitz Victor Hugo V. Carrijo Luiz Souza Carlos Farinha Mário J. Costa

Background/Objectives: The use of buoyant equipment in water fitness sessions appears to elicit a more intense physiological response in water exercises. However, it remains unknown whether the shape of the equipment influences these responses. The present study aimed to analyze and compare the physiological responses and perceived effort while older women using different buoyant dumbbells during horizontal adduction/abduction of the upper limbs (HA exercise). Methods: Ten older women (76.1 ± 5.3 years of age) attended two assessment sessions to perform HA exercise at a music cadence of 120 bpm with different buoyant dumbbells (one pair for each session): round hydro and hydro crystal. Mean heart rate (HR), systolic and diastolic blood pressures (SBP and DBP, respectively), double product (DPr), blood lactate concentration ([La−), and rate of perceived effort (RPE) were assessed according to pre-exercise (rest), warm-up and the HA exercise (five min effort). Results: The mean HR was also analyzed according to the percentage (%) of the predicted maximal theoretical HR (HRmax). Older women reached ~56 and 61% of HRmax using crystal and round dumbbells, respectively. Differences were found in mean HR, [La−], and RPE with the round dumbbell showing greater values than the crystal dumbbell. Although no differences were found in SBP and DBP, DPr was higher when women used the round dumbbells. Conclusions: The shape of buoyant dumbbells seems to define acute responses of older women as the round dumbbell promotes a more intense physiological response and perceived effort when compared to the crystal dumbbell.

Physiologia doi: 10.3390/physiologia5020018

Authors: Panagiota Athanasopoulou Georgia-Eirini Deligiannidou Paraskevi Basdeki Elena Deligianni Pinelopi Kryona Georgios Kaltsos Diamanto Lazari Athanasios Papadopoulos Konstantinos Papadimitriou Christos Kontogiorgis

Objective: Protein supplements (PSs) are widely consumed by professional and non-professional athletes, yet research on non-athletic PS users’ perceptions, motivations, and health risk awareness is limited. This study aimed to investigate non-professional athletes’ PS patterns of use, motivations, and safety. Methods: A cross-sectional study was conducted using a constructed questionnaire reporting on PS usage trends, exercise habits, and demographic factors. Adult respondents were recruited from gyms, athletic organizations, amusement parks, and playing fields. Results: We received 1100 responses, and 327 were PS users. From the total of PS users, there was a prevalence of PS use in males [(203 (62%)]; adults in the age group of 25–34 [136 (42%)], p < 0.001; and participants with a normal BMI (189, 58%), p < 0.001. Following high-intensity fitness exercise sessions and engagement with more than two types of physical activity were associated with more than doubled odds of PS consumption (p < 0.001). The main reasons for PS intake were for muscle mass increase (35%) and recovery (18%), and protein powder was the most popular PS (279; 64%). The main channels of information for PS use were Web/social media (50, 40%) and coaches (54, 43.2%), while one out of two [35 (49%); p = 0.008] of those engaged in more than two types of physical exercise declared that PSs are good for health. Conclusion: The findings highlight demographic, behavioral, and informational factors shaping PS consumption in non-professional athletes. Despite the perceived benefits, reliance on non-expert sources and unregulated products raises concerns about consumer awareness and safety, while educational initiatives to promote evidence-based supplementation practices are deemed crucial.

Physiologia doi: 10.3390/physiologia5020017

Authors: Nicholas J. Kontos Joshua S. Godwin Anthony Agyin-Birikorang Darren G. Candow Christopher M. Lockwood Michael D. Roberts Christopher B. Mobley

Background/Objectives: Creatine monohydrate (CRE) is a popular nutritional supplement that increases lean/muscle mass accretion. Although data regarding CRE and its effects on muscle protein synthesis are mixed, we hypothesized that CRE may potentiate/extend the anabolic response to essential amino acids given that CRE acts as a high-energy phosphate buffer to potentially amplify anabolic signaling. Therefore, we used an in vitro model to determine whether CRE synergistically enhances myotube protein synthesis and the anabolic signaling responses to EAA-rich whey protein (WP). Methods: C2C12 murine myotubes were treated with control media containing PBS (CTL), WP serum (5 mg/mL), CRE (10 mM), or WP + CRE. Myotubes were collected following 1, 4, and 24 h treatments (n = 6 replicates per treatment and time point) and assayed for relative creatine levels, myotube protein synthesis levels, and phosphorylation markers. Results: Cellular creatine levels were greater in CRE and WP + CRE versus CTL and WP at all treatment time points (p < 0.05). The protein synthesis levels with 4 hr treatments with WP and WP + CRE were greater compared to the CTL (p = 0.036 and p < 0.001, respectively), and 24 h levels were greater with WP versus other treatments (p < 0.05). p-p70S6K (Ser389) and p-rpS6 (Ser235/236) were greater with WP at 1 h compared to all other treatments (p < 0.05). No effects across time points were observed for p-mTOR (Ser2448), p-4E-BP1 (Thr37/46), or p-AMPKα (Thr172). Conclusions: WP increases protein synthesis and anabolic signaling with no additive effect from CRE. However, given that myotubes were not stressed nor stimulated to contract, such models are needed with the current treatment schematic to examine potential interactions.

Physiologia doi: 10.3390/physiologia5020016

Authors: Alan T. Ky Ryan A. Dunn Marcos S. Keefe Yasuki Sekiguchi

Introduction: Oral rehydration reduces thirst sensation (TS), which may negatively affect autonomic function, measured by heart-rate variability (HRV). However, it is unclear if this effect is independent of hydration changes. This study examines whether TS influences autonomic function between intravenous and oral rehydration. Methods: Twelve males (mean ± SD; age, 29 ± 12 years; 74.7 ± 7.9 kg; 179.4 ± 7.0 cm; VO2max, 49.8± 6.6 mL·kg−1·min−1) cycled at 55% VO2max for 90 min followed by a 12 km time trial. Two experimental conditions were performed in a counterbalanced, randomized order; (a) the high thirst (HT) group were infused 25 mL of isotonic saline every 5 min via an intravenous tube, and (b) the low thirst (LT) group ingested 25 mL of water every 5 min. TS and heart rate were collected every 5 min. HRV was assessed pre exercise, post steady-state exercise, and post time trial. HRV parameters included time domain, frequency domain, and non-linear measures analyzed by two-way repeated measures ANOVA. Results: There was a significant time x condition for the root mean square of successive RR interval differences (RMSSDlog), high-frequency (HF) power, and SD1 (p < 0.05). In LT, RMSSDlog decreased from Pre to Mid (3.71 ± 0.61 ms to 2.53 ± 1.15 ms, p < 0.01) and Pre to Post (2.18 ± 0.90 ms, p < 0.01) but stabilized from Mid to Post (p = 0.39). High-frequency (HF) power in HT was maintained from Pre (3.7 ± 0.6 nu) to Mid (3.4 ± 0.8 nu, p = 0.21) but decreased from Pre to Post (2.5 ± 0.7 nu, p < 0.01) and Mid to Post (p < 0.01). LT decreased in HF power from Pre (3.7 ± 0.5 nu) to Mid (3.0 ± 0.8 nu, p < 0.01) and Pre to Post (3.0 ± 0.7 nu, p < 0.01); Mid and Post was maintained (p = 0.99). SD1, decreased in HT (Pre: 3.4 ± 0.4 ms, Mid: 2.0 ± 1.1 ms, Post: 1.1 ± 0.5 ms; all comparisons p < 0.05). In LT, SD1 decreased from Pre (3.4 ± 0.6 ms) to Mid (2.18 ± 1.15 ms, p < 0.01) and Pre to Post (1.83 ± 0.90 ms, p < 0.01), but stabilized Mid to Post (p = 0.39). Conclusion: Satiating thirst through oral rehydration increases parasympathetic activity post exercise, reducing stress and increasing recovery between exercise bouts. These findings have implications for optimizing rehydration strategies in sports and occupational settings.

Physiologia doi: 10.3390/physiologia5020015

Authors: Robert W. Smith Jocelyn E. Arnett Dolores G. Ortega Trevor D. Roberts Dona J. McCanlies Richard J. Schmidt Glen O. Johnson Terry J. Housh

Background/Objectives: Studies of the effects of anchor schemes (perceived intensity vs. relative intensity) on muscular performance have reported mixed findings. Therefore, the present study examined the effects of different anchor schemes on time-to-task failure (TTF), muscular performance, neuromuscular responses, and potentiated twitch torque (PTT). Methods: On separate days, 15 men (age = 21.5 ± 2.3 yrs) performed forearm flexion maximal voluntary isometric contractions (MVICs) before and after sustained tasks anchored to a rating of perceived exertion of 6 (RPEFT) and with the torque at RPE = 6 (TRQFT). Electromyographic amplitude (EMG AMP) and mean power frequency (EMG MPF) were recorded from the biceps brachii (BB). Supramaximal stimuli were delivered to the motor nerve of the BB following the MVICs to quantify the PTT. Repeated measures ANOVAs assessed the mean differences between anchor schemes for MVIC, neuromuscular, and PTT responses. Paired t-tests compared the magnitude of percent changes for the dependent variables. Results: The TTF for the RPEFT was longer (p < 0.001) than the TRQFT, but the MVIC decreased similarly (12.7 ± 9.5% vs. 20.3 ± 7.9%, p = 0.054). Electromyographic AMP did not change (p = 0.288), while EMG MPF decreased (15.7 ± 10.2%, p < 0.011) for the TRQFT only. Mean decreases in PTT were comparable for both tasks (p < 0.003), although the percent change was greater for the TRQFT (49.6 ± 16.1%, p < 0.001). Conclusions: The differences in TTF, but similar decreases in MVIC suggested that participants reached a sensory tolerance limit. Based on EMG MPF and PTT, the TRQFT caused greater peripheral perturbations to contractile function than the RPEFT.

Physiologia doi: 10.3390/physiologia5020014

Authors: Martin Fernando Bruzzese Gastón César García Carlos Rodolfo Arcuri Mauro Darío Santander Jeremías David Secchi José Augusto Rodrigues dos Santos Rodrigo Zacca

Background: Extensive data exists on external load during training and competition, but a significant gap remains in understanding internal physiological load, particularly in protocols conducted in ecological settings. Given the scarcity of studies on the on-field cardiorespiratory profiles of national-level athletes, especially in Argentine soccer, this study aimed to identify the on-field cardiorespiratory fitness profile of ten highly trained youth field soccer players (13.6 ± 1.3 years old) from both the first league of the Argentine Football Association and members of the national team in their age group category in the current year. Methods: Each athlete performed an on-field cardiorespiratory exercise test (20-m Shuttle Run Test, 20-m SRT) with the COSMED K5 wearable metabolic system (COSMED, Rome, Italy) in dynamic micro-mixing chamber mode. The 20-m Shuttle Run Test involves running back and forth between two lines set 20 m apart, following the pace set by an audio signal. The test starts at a running velocity of 8.5 km·h−1 and increases by 0.5 km·h−1 each min. Results: Mean velocity at maximal oxygen uptake (vV˙O2max) was 12.3 ± 0.7 km·h−1. The maximal oxygen uptake (V˙O2max) on-field was 67.1 ± 5.3 mL·kg−1·min−1. The V˙O2 at the first and second ventilatory thresholds (VT1 and VT2) were identified at 67.0 ± 3.0% V˙O2max (44.9 ± 3.3 mL·kg−1·min−1) and 84.7 ± 3.7% V˙O2max (56.8 ± 3.8 mL·kg−1·min−1), respectively. Conclusions: This is a scarce on-field gas exchange assessment, conducted in an ecological context using a portable analyzer with highly trained national-level youth soccer players from the Argentine youth national team, which underlines their cardiorespiratory fitness, showcases their high-performance potential, offers valuable insights into a selective group of players, and provides a reference for larger-scale research on elite youth soccer and the long-term development of aerobic power and capacity.

Physiologia doi: 10.3390/physiologia5020013

Authors: Masab Mansoor Andrew Ibrahim Ali Hamide Tyler Tran Ethan Candreva Jad Baltaji

Background/Objectives: Neurodegenerative diseases represent a growing global health challenge with limited therapeutic options. Physical exercise has emerged as a promising non-pharmacological intervention with potential neuroprotective effects. This narrative review examines the mechanisms through which exercise induces neuroplasticity and their implications for neurodegenerative disease prevention. Methods: We synthesized evidence from molecular, animal, and human studies on exercise-induced neuroplasticity and neurodegenerative disease prevention through a comprehensive literature review. Results: Exercise enhances neuroplasticity through multiple pathways: (1) neurotrophic signaling (BDNF, IGF-1, VEGF), (2) neuroendocrine regulation, (3) epigenetic modifications, and (4) metabolic pathway optimization. These molecular changes support structural adaptations including hippocampal neurogenesis, enhanced synaptic plasticity, improved cerebrovascular function, and optimized brain network connectivity. Exercise directly impacts pathological features of neurodegenerative diseases by reducing protein aggregation, attenuating excitotoxicity and oxidative stress, and enhancing mitochondrial function. Clinical evidence consistently demonstrates associations between physical activity and reduced neurodegenerative risk, with intervention studies supporting causal benefits on cognitive function and brain structure. Conclusions: Exercise represents a multi-target intervention addressing several pathological mechanisms simultaneously across various neurodegenerative conditions. Its accessibility, minimal side effects, and multiple health benefits position it as a promising preventive strategy. Future research should focus on understanding individual response variability, developing sensitive biomarkers, and creating personalized exercise prescriptions for optimal neuroprotection.

Physiologia doi: 10.3390/physiologia5020012

Authors: Marcel Lopes dos Santos Robert G. Lockie Robin Orr Taylor Dinyer-McNeely Doug Smith Samantha McDonald Jay Dawes

Background: The aim of this systematic review was to collect, appraise, and synthesize the available information related to the cardiovascular and metabolic demands of commonly performed firefighting tasks while wearing personal protective equipment (PPE) inclusive of self-contained breathing apparatus (SCBA). Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, academic databases (PubMed, Embase, and SPORTDiscus databases) were searched for relevant records which were subjected to dedicated eligibility criteria with included articles quality appraised using the Critical Appraisal Skills Programme (CASP) checklist. Results: Of an initial 1463 identified records, 20 studies with a mean CASP of 8.26/11 informed the review. A myriad of varying field tests have been employed to determine physical preparedness and assess the metabolic demand of firefighting. Conclusions: The volume of evidence suggests that PPE and SCBA must be incorporated when assessing the demands of firefighting as they clearly increase the metabolic cost of combined simulated firefighting tasks. Although real-world scenarios are made up of a combination of individual firefighting tasks, there remains a clear need to determine the metabolic cost of isolated firefighting tasks such as forcible entry, hose drag, victim rescue, ladder raise, and stair climbing with and without PPE and SCBA. The quantification of the metabolic demand of these tasks may assist tactical trainers when designing simulated scenarios and training programs for firefighters.

Physiologia doi: 10.3390/physiologia5010011

Authors: Christos N. Hassiotis Konstantinos E. Vlachonasios

Background/Objectives The plants of the Lavandula genus are widely investigated because of their significance for pharmaceuticals and food. The composition of lavender essential oil is determined by genotype and can be induced by environmental, ontogenetic factors, and morphogenetic features. Linalool and linalyl acetate are the most abundant compounds, performing essential ecological functions and participating in lavender’s therapeutic properties. This review reports on the biosynthesis of lavender oil compounds and summarises the environmental, developmental, and molecular factors contributing to essential oil composition in lavender flowers. Results Floral developmental stage and ontogeny are fundamental for optimal harvest time. The harvesting period for high-quality lavender essential oil is affected by environmental and developmental factors that influence the gene expression of monoterpene biosynthesis. Conclusions These findings indicate the appropriate features for high-quality lavender essential oil and contribute to information that may allow for the manipulation of monoterpenes biosynthesis in lavender breeding efforts.

Physiologia doi: 10.3390/physiologia5010010

Authors: Daniel J. McDonough

Heart failure is a leading cause of morbidity and mortality worldwide [...]

Physiologia doi: 10.3390/physiologia5010009

Authors: Luca Bonisoli Luca Forti Laura Arru

Background: Building on our previous work, this study presents a cost-effective, non-invasive methodology for recording, identifying, and analyzing plant ultrasonic emissions in dynamic environments, both indoor and outdoor. While previous research has utilized contactless microphones to compare water-stressed and hydrated plants indoors, to the best of our knowledge, no similar studies have been conducted in outdoor conditions. The objective of this study is to address the need for scalable, accessible tools for monitoring plant stress in a variety of environmental settings. Methods: Pinto bean and tomato plants were exposed to water stress conditions and monitored in both indoor and outdoor environments, with plant acoustic emissions recorded using an ultrasonic microphone. Results: The proposed methodology successfully recognized plant ultrasonic emissions even in the presence of high levels of environmental noise typical of outdoor conditions (e.g., wind, rain, or insect chirping). Conclusions: We argue that this method, with its minimal equipment requirements, is a valuable addition to the range of tools available for Plant Acoustics research, offering the potential for non-invasive monitoring in a variety of different environments.

Physiologia doi: 10.3390/physiologia5010008

Authors: Ryota Sone Kenji Yamamoto Shinsuke Tamai Honoka Goji Kenji Ohishi

Background/Objectives: Volleyball training camps are known to reduce salivary secretory immunoglobulin A (s-SIgA); however, when it begins to decrease is unclear. The validity of a simple device for quantifying s-SIgA is lacking; hence, this study aimed to observe detailed s-SIgA changes during a volleyball training camp after moving to a high altitude and to investigate the difference in s-SIgA response between the two quantification methods, namely, the enzyme-linked immunosorbent assay (ELISA) and lateral flow device (LFD). Methods: Twenty-four male university volleyball players participated in the observational study. Measurements were collected at three points of the training camp (days 1, 4, and 7). The s-SIgA was quantified using conventional ELISA and the new LFD method. Results: The s-SIgA concentrations quantified using the two methods decreased significantly by day 4 (p < 0.05) and continued to decrease until day 7 (p < 0.05). A significant positive correlation was found between the s-SIgA concentrations quantified using the LFD and ELISA (p < 0.05, rs = 0.319). Conclusions: These results indicate that a high-altitude volleyball training camp may suppress oral immune function by day 4 and that the evaluation of s-SIgA concentration using the LFD method is beneficial. A faster and easier method for assessing s-SIgA could contribute to athletes’ condition management strategies.