Search Results (688)

Background/Objective: A substantial proportion of infected individuals develop persistent symptoms after the acute phase of COVID-19, regardless of initial disease severity. Long COVID (LC) remains a public health challenge characterized by impaired functional exercise capacity (FEC) and quality of life (QoL). We systematically synthesized evidence on the effects of in-person outpatient pulmonary rehabilitation (OPR) with individualized and supervised exercise in adults with LC. Methods: Following PROSPERO (CRD42023389365), this study reviewed randomized controlled trials (RCTs) and observational cohort studies (OCSs) published between November 2019 and January 2026 in MEDLINE/PubMed, Web of Science, PEDro, and EMBASE. Results: Fifteen studies (n = 803) were included. OPR improved FEC (6MWT; MD: 53.72 m, 95% CI 43.69–63.75) and 30″SST (MD: 4.68, 95% CI 3.59–5.77) and reduced exertional dyspnea. RCTs showed benefits in physical (MD: 8.04, 95% CI 3.02–13.05) and mental QoL (MD: 6.60, 95% CI 2.01–11.18) and dyspnea impact, with inconsistent PF findings. Fatigue showed a trend toward improvement but was measured using heterogeneous patient-reported tools in RCTs and OCSs. Conclusions: Supervised PR improves FEC, QoL, and dyspnea in individuals with LC. In patients with fatigue/PEM, systematic assessment and continuous symptom monitoring are essential. High-quality controlled studies are needed to strengthen evidence and clinical guide. Full article

Background/Objectives: Persistent symptoms following SARS-CoV-2 infection pose a substantial burden in occupational settings. This study aimed to characterize symptoms following work-related SARS-CoV-2 infection and to assess their associations with sociodemographic and clinical factors. Methods: Data were obtained from a multicenter clinical registry of insured individuals referred for persistent symptoms 12 weeks after laboratory-confirmed work-related SARS-CoV-2 infection. Participants were assessed within a standardized post-COVID diagnostic program at six specialized clinics for occupational accident insurance in Germany. Persistent symptoms reported by ≥50% of participants were analyzed using generalized linear mixed models with random intercepts for center. Results: A total of 1511 participants (76.7% women; median age 54 years) were included, with a median interval of 16 months between infection and assessment. On average, participants reported ten persistent symptoms. The most frequent complaints were limited physical capacity (95.6%), concentration difficulties (78.8%), dyspnea (70.5%), exhaustion/tiredness (68.9%), and memory difficulties (67.5%). Individuals reporting more than ten acute symptoms had increased odds of persistent complaints (ORs between 2.1 and 4.66). Hospitalization was independently associated with persistent dyspnea (OR 1.62; 95%CI 1.17–2.25). Reinfections were linked to exhaustion and cognitive fatigue. Compared with Omicron, wild-type infection was associated with higher odds of concentration difficulties (OR 1.65; 95%CI 1.17–2.33). Comorbidities demonstrated symptom-specific associations. Conclusions: Among individuals with work-related SARS-CoV-2 infection, limited physical capacity and cognitive impairments were the most frequently reported symptoms, and higher acute symptom burden was strongly associated with the development of persistent symptoms. These findings support course-oriented evaluation and symptom-specific approaches in occupational disease assessment and management. Full article

Background: Weightlifters commonly use upper-extremity high-load training, which encompasses techniques ranging from momentary failure to non-failure. However, little is known about how this training affects posture and core endurance, despite knowing that these factors are risk factors for weightlifting injuries. Therefore, this study aimed to determine the immediate effects of upper-extremity high-load training to momentary failure versus non-failure, using the dumbbell overhead press, on posture and core endurance in recreational collegiate weightlifters. Methods: Fifty recreational weightlifters aged 18–24 with two years of upper extremity resistance training experience were recruited for this study. The participants performed dumbbell overhead press exercises under high-load failure (HL-F) and high-load non-failure (HL-NF) conditions two days after 1RM testing and calculation of the 80% 1RM load. The study analyzed postural changes using photographic data processed in Kinovea, while core endurance was assessed during a prone plank test. Standardized warm-ups, controlled exercise execution, and pre- and post-exercise assessments were conducted to measure core endurance and postural alterations. Results: The thoracic kyphosis angle, together with scapular balance angle and lateral scapular slide distance, increased significantly after HL-F compared to the unloading state, while the craniovertebral angle and prone plank time decreased significantly (p < 0.05). The HL-NF condition showed no statistically significant differences relative to the unloading measurements (p > 0.05). The unloading measurements across testing days were consistent, indicating no carryover effect (p > 0.05). Conclusions: The findings indicate that high-load training to failure adversely affects posture and core endurance, increasing fatigue and potentially increasing the risk of acute injuries. Non-failure training maintains stability, underscoring the importance of strategic program design for achieving optimal performance while minimizing adverse effects. Full article

Introduction: Circuit resistance training is widely used to enhance physical performance. However, the acute-performance- and fatigue-related effects of exercise order and volume in circuit training, particularly between upper and lower limbs, remain unclear. Objectives: This study examined acute velocity-based responses to different exercise orders and volumes during full-body circuit resistance training. Methods: Thirty resistance-trained adults completed four circuit protocols: alternating exercises with maximal repetitions per exercise (A1), grouped exercises with maximal repetitions per exercise (G1), alternating exercises with 50% of maximal repetitions in the first round (A2), and grouped exercises with 50% of maximal repetitions in the first round (G2). Mean propulsive velocity (MPV) in the bench press and squat at 60% 1RM was assessed before and after each circuit. Results: A significant main effect of Time was observed for both bench press and squat MPV (p < 0.001), with no Intervention × Time interactions. Alternating configurations showed larger effect sizes, indicating greater velocity loss. Under equal volume, upper limbs exhibited greater performance decline than lower limbs. Conclusions: Although exercise order did not result in statistically significant differences, alternating configurations induced a greater magnitude of fatigue-related performance decline than grouped configurations, particularly in upper-body exercises. Full article

Background/Objectives: Understanding how different fatigue contexts influence muscle architecture is essential for optimizing training and recovery strategies in endurance athletes. Ultramarathon running involves prolonged mechanical load and high eccentric demands, which may elicit different acute responses compared to controlled laboratory protocols. This study aimed to examine the effects of time, condition (laboratory vs. race), and muscle on ultrasound-derived muscle architecture in ultratrail runners. Methods: A repeated-measures within-subject design was employed. Forty ultratrail runners completed two fatigue conditions: (1) a standardized laboratory downhill running protocol and (2) an ultramarathon race (CSP 2025; 106 km, +5600 m elevation gain). Muscle thickness and pennation angle of the rectus femoris, vastus lateralis, and medial gastrocnemius were assessed using ultrasound before and after each condition. Linear mixed models were used to evaluate the effects of time, condition, muscle, and their interactions. Results: Forty participants were recruited; 29 completed all assessments. No significant effects of time or condition were observed for muscle thickness, and no interaction effects were detected, indicating that muscle size remained stable across conditions and time points. A significant main effect of muscle was identified (p < 0.001), reflecting inherent morphological differences, with greater thickness in the vastus lateralis compared to the rectus femoris and medial gastrocnemius. In contrast, pennation angle showed a significant main effect of condition (p = 0.031) and a significant condition × muscle interaction (p = 0.005), indicating muscle-specific differences between laboratory and race contexts. No significant effect of time was observed for pennation angle. Conclusions: Muscle thickness appears to remain stable following acute fatigue, regardless of the assessment context. In contrast, pennation angle may be more sensitive to condition-specific and muscle-dependent factors. These findings suggest that ultrasound-derived architectural changes observed immediately after exercise likely reflect acute physiological responses rather than true structural adaptations. Therefore, the interpretation of muscle architecture should consider both contextual factors and methodological constraints. Full article

Background: This study aimed to analyze the acute effects of an official Muay Thai championship on neuromuscular performance, assessing changes in upper- and lower-limb power before and after competition, as well as differences according to competitive outcome (winners vs. losers). Methods: Thirty-three amateur Muay Thai athletes (17 men and 16 women) performed a countermovement jump (CMJ) and a reactive push-up test (RPU) immediately before and after their bouts. Neuromuscular performance changes were analyzed using mixed-design ANOVA, and a binary logistic regression was conducted to examine the association between post-competition performance and match outcome. Results: Significant post-competition declines were observed in both CMJ and RPU performance (p < 0.001), indicating acute neuromuscular fatigue. Men exhibited higher performance values than women in both tests, with sex-specific differences in CMJ fatigue magnitude. When analyzed by competitive outcome, losers showed substantially greater performance decrements than winners, particularly in CMJ. Logistic regression revealed that post-competition CMJ performance was a significant predictor of winning, with higher CMJ values associated with greater odds of competitive success. Conclusions: An official Muay Thai bout induces marked acute neuromuscular fatigue affecting both upper and lower limbs, with greater impairments observed in non-winning athletes. The ability to maintain lower-limb explosive power under fatigue appears to be associated with competitive success. Simple neuromuscular assessments such as CMJ and RPU may be useful tools for monitoring fatigue, guiding tactical decisions, and informing post-competition recovery strategies in Muay Thai athletes. Full article

Objective: This study aimed to investigate the acute effects of intermittent high-intensity badminton court exercise on cardiac autonomic modulation in male non-elite badminton players. Methods: This study employed a single-arm, repeated-measures experimental design, recruiting 25 healthy male collegiate badminton players. Participants completed five sets of high-intensity intermittent court tests until exhaustion, followed by calculation of stress index (SI), time-domain (RMSSD and SDNN), and frequency-domain (LF, HF, and LF/HF ratio) parameters at rest using a certified heart rate variability (HRV) analyzer. Repeated-measures ANOVA and effect size (partial η² and Hedges’ g) were used to assess changes and recovery trends of HRV parameters across time points: pre-test, immediate, 15 min, 24 h, and 48 h post-exercise. Results: (1) Stress index: The overall temporal trend showed statistical significance (p < 0.001, partial η² = 0.236, large effect size). Compared to pre-test, immediate and 15 min post-exercise increases were 8.24 (95% CI: 0.63–15.85) and 9.84 (95% CI: 3.07–16.61) respectively, with Hedges’ g values of 0.77 and 0.99 (p < 0.001, large effect sizes). Values returned to pre-test levels at 24 and 48 h with no significant differences (p > 0.05). (2) Time-domain parameters: The overall temporal trend was statistically significant (p < 0.001, partial η² = 0.553 for RMSSD and 0.586 for SDNN, both large effect sizes). Immediate post-exercise decreases in RMSSD and SDNN were 35.44 (95% CI: 21.95, 48.93) and 48.44 (95% CI: 32.49, 64.38) respectively, with Hedges’ g values of 2.31 and 2.78 (p < 0.001, large effect sizes). At 15 min, decreases were 31.64 (17.85, 45.42) and 41.48 (26.23, 56.72) respectively, with Hedges’ g values of 1.99 and 2.25 (p < 0.001, large effect sizes). Values returned to pre-test levels at 24 and 48 h with no significant differences (p > 0.05). (3) Frequency-domain parameters: Compared to pre-test, differences in LF, HF, and LF/HF were not statistically significant at any time point (all p > 0.05). Conclusions: Following high-intensity exercise leading to peripheral fatigue, cardiac autonomic function demonstrates a “suppression–recovery” dynamic pattern: cardiac stress levels increase significantly within 15 min post-exercise, with decreased overall HRV regulatory capacity and strong inhibition of parasympathetic activity; HRV status may return to baseline levels after 24 h. However, the frequency-domain indices of HRV showed no significant changes in response to the acute effects of high-intensity exercise. Full article

Esports are a rapidly expanding form of competitive activity that demand high levels of cognitive alertness, motor precision, stress management, and resilience to mental and physical fatigue. At the same time, the sedentary lifestyle, extended screen exposure, and psychological pressures associated with competitive gaming raise concerns for both performance and long-term health. Growing evidence highlights the importance of nutrition and lifestyle behaviors in supporting cognitive performance and overall competitive demands. While balanced dietary patterns and adequate hydration are essential, dietary supplements may provide additional benefits when used appropriately and under professional guidance. However, the current research is limited by a predominance of cross-sectional and self-reported studies, short-term or acute interventions, small sample sizes, and insufficient emphasis on esports-specific and personalized strategies. This review examines existing evidence on individualized nutrition, supplementation, and lifestyle strategies in esports, identifies key methodological limitations, and outlines future directions to inform evidence-based practice for athletes, practitioners, and organizations seeking to optimize cognitive performance, well-being, and long-term sustainability in this emerging field. Full article

Myocarditis and inflammatory cardiomyopathy are inflammatory diseases of the heart muscle that can have both infectious and non-infectious causes. They can be caused by an unresolved viral infection or other infection, or they can be autoimmune, toxic, or allergic in nature. The specific identification of the pathogen and/or confirmation of inflammation can only be achieved through direct tissue analysis using endomyocardial biopsy (EMB), as neither detection of the virus nor assessment of the quality and intensity of the inflammation is possible using non-invasive methods. Accordingly, the removal and analysis of an EMB is considered the diagnostic gold standard in international guidelines and statements. The sudden onset of atypical angina pectoris and initially exertion-dependent dyspnea, as well as arrhythmias, pericardial effusion, and progressive symptoms of heart failure, indicate an acute inflammatory process of the myocardium. In addition, nonspecific symptoms such as fatigue and reduced physical performance may also occur. Diagnostic evaluation includes an electrocardiogram (ECG), cardiac imaging, and laboratory tests. The analysis of the EMB is crucial for a definitive diagnosis and thus for the initiation of an etiology-based, specific and personalized therapy. This includes histological and immunohistochemical inflammation diagnostics as well as molecular virological diagnostics. These enable both the detection of viruses and the assessment of transcriptional virus activity. New analyses using metagenomic next generation sequencing (NGS) techniques provide insights of enormous diagnostic and therapeutic relevance. This applies both to the spectrum of detectable pathogens and to the possibility of confirming transcriptional viral activity. In addition, gene expression profiling enables the differentiation of specific forms of myocardial inflammation (e.g., giant cell myocarditis, cardiac sarcoidosis, and eosinophilic myocarditis) and reduces the influence of “sampling errors” in focal inflammatory processes. The treatment of heart failure or ventricular arrhythmias is always symptomatic according to general evidence-based guidelines. In severe cases, mechanical circulatory support or even a heart transplant may be necessary. Patients with histologically confirmed myocardial inflammation or intramyocardial viral infection can be offered specific, causal, and personalized therapy. These patients can be successfully treated with immunosuppressive or antiviral therapy, which significantly improves the prognosis of the disease. Full article

Mental fatigue is a psychobiological state induced by sustained effortful cognitive efforts during daily life activities. Yet research efforts in exercise science have focused primarily on performance implications for athletes to the point of exclusion of vulnerable populations for which mental fatigue may be a health risk. This narrative review aims to clarify the role of mental fatigue on population health. Evidence suggest mental fatigue predisposes people to acute events related to temporary performance impairments (e.g., falls), and chronic diseases related to sedentarism (e.g., stroke, diabetes), as mental fatigue de-motivates people to engage in physical activity. Major risks are experienced by people with higher fatigability (i.e., people for whom mental fatigue is induced by less effortful tasks) and lower performance capacity. However, the few available information about moderators of fatigability and the lack of a normative protocol to assess mental fatigue are limiting the prevention of mental fatigue. Several strategies are used to counter mental fatigue acutely (e.g., caffeine ingestion); however, enduring countermeasures intended to alter psychobiological sequelae of mental fatigue, such as Brain Endurance and other trainings, are the only proved long-term countermeasures for mental fatigue. Yet the effectiveness of these interventions should be tested in populations with major risk for mental fatigue. We present a model identifying putative pathways through which mental fatigue may contribute to health risks to guide future investigations seeking to (a) evaluate the role of mental fatigue as a threat to health and well-being and (b) design interventions to mitigate the effects of mental fatigue in vulnerable populations. Full article

Objective: The present study aimed to verify two key hypotheses: (1) whether the session rating of perceived exertion (sRPE) can serve as a reliable indicator for workload monitoring in cricket and (2) to compare the injury risk sensitivity of sRPE-derived indicators—including the coupled and uncoupled acute:chronic workload ratio (ACWR), exponentially weighted moving average (EWMA), and robust exponential decreasing index (REDI)—across three pre-specified latency periods (no latency, 7-day latency, and 14-day latency), and to identify the optimal indicator and latency period for cricket injury risk assessment. Material: Twenty-four elite female cricket athletes from the Chinese National Women’s Cricket Team were monitored during daily training throughout the Los Angeles Olympic Games preparation period. Methods: Correlation analysis, Kendall’s tau correlation coefficients, and Bland–Altman plots were employed to assess the relationships and consistency between sRPE and various workload indicators. ROC curves were constructed to compare the performance of sRPE-derived indicators for injury risk across the three pre-specified latency conditions. Results: sRPE and its derived indicators exhibited significant correlations with health status indicators (sleep, fatigue, delayed onset muscle soreness (DOMS), stress, mood, and resting heart rate (RHR)) and physiological and biochemical indicators (testosterone, cortisol), with the majority of these correlations reaching the 0.01 significance level (p < 0.01). Kendall’s tau correlation coefficients and Bland–Altman plots revealed that sRPE and ACWR based on EWMA (hereafter referred to as EWMA) had moderate correlations with health status indicators, while ACWR based on REDI (hereafter referred to as REDI) showed a strong correlation with such indicators. sRPE and its derived indicators were strongly correlated with physiological and biochemical indicators (Kendall’s tau > 0.8) with good consistency, as the majority of scattered points fell within the limits of agreement (mean difference ± 1.96 × standard deviation, MD ± 1.96 × SD). Analysis of injury risk sensitivity indicated that the 7-day latency model yielded the highest average area under the curve (AUC = 0.85). Among all indicators, REDI and EWMA achieved the highest AUC values (AUC = 0.665 and 0.667, respectively; p < 0.001). Notably, EWMA exhibited optimal performance in the 7-day latency time series (AUC = 0.859, >0.80), followed by REDI under the 7-day latency condition (AUC = 0.857). Conclusion: EWMA with 7-day latency is a more sensitive indicator for detecting injury risk. Full article

Background: Sodium bicarbonate (SB) supplementation can enhance performance in short, high-intensity movements. However, its effectiveness in team sports such as rugby remains insufficiently explored. Methods: In this double-blind, parallel, controlled trial, 17 male professional rugby players ingested SB (0.3 g/kg) or a placebo 90 min before a high-intensity, rugby-specific training session monitored via GPS. The training session was conducted under real-world conditions to enhance ecological validity. Physical performance (countermovement jump, CMJ), fatigue markers (capillary lactate and ratings of perceived exertion, RPE), and gastrointestinal (GI) symptoms were assessed pre- and post-exercise. Results: No significant pre–post changes were observed in CMJ performance in either group. Lactate concentrations increased from pre- to post-exercise in both groups (both p < 0.001). The SB group showed higher GI symptom severity before, during and after exercise versus placebo, with several symptoms increasing over time solely in the SB group (p < 0.05). RPE increased similarly in both groups (SB: p = 0.012; PLA: p = 0.008). Due to the small sample size, only moderate-to-large within-group effects and very large between-group differences could be detected; therefore, the study was powered to detect moderate-to-large within-group effects but underpowered for detecting between-group differences. Conclusions: Acute SB ingestion at 0.3 g/kg did not result in detectable improvements in performance or fatigue markers during rugby-specific high-intensity training and was associated with a greater incidence of GI discomfort; however, the study was underpowered to detect small between-group differences. This study was registered on 23 May 2025 on ClinicalTrials.gov (NCT07017582). Full article

This study investigated the acute effects of anodal transcranial direct current stimulation (a-tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) and primary motor cortex (M1) on neuromuscular performance during a velocity-based back squat exercise. Fifteen recreationally trained men participated in a randomized, double-blind, crossover design, completing three experimental conditions (SHAM, DLPFC, and M1 stimulation) consisting of 20 min of 2 mA a-tDCS followed by a squat protocol performed to a 15% velocity loss threshold. Total repetitions, repetitions per set, mean concentric velocity, and rating of perceived exertion (RPE) were recorded. No significant differences between stimulation conditions were observed for any outcome variable. However, two individuals showed reversed responses, consistent with previously reported inter-individual variability in response to tDCS. Given the high inter-individual variability in response to a-tDCS, we additionally performed a post hoc sensitivity analysis based on response direction relative to SHAM. This analysis indicated that a-tDCS over M1 and DLPFC resulted in a significantly greater total number of repetitions compared with SHAM, whereas repetitions per set, mean velocity, and RPE were not different between conditions. Accordingly, a systematic and individualized approach may be needed to address inter-individual variability in response to tDCS to optimize its effect on fatigue tolerance. Full article

Sleep banking, i.e., preemptively obtaining extra sleep prior to anticipated sleep loss, has been proposed as a strategy to reduce the cognitive and physiological consequences of sleep deprivation. However, our understanding remains incomplete regarding the effectiveness of preemptive sleep extension in enhancing resilience to sleep loss. A comprehensive literature search was conducted using PubMed, MEDLINE, and Embase for studies published between 2004 and 2025. Following a comprehensive literature search, we identified 12 studies meeting the inclusion criteria—seven primary experimental trials comprising approximately 140 participants, predominantly healthy young adults aged 18–39 years. We evaluated the effects of sleep banking on cognitive performance, mood, physiological parameters, and real-world outcomes. Included studies encompassed experimental laboratory trials, observational research, and field studies in occupational and athletic settings. Although the number of studies on sleep banking remains limited, experimental evidence demonstrates that preemptive sleep extension improves objective alertness and vigilance during subsequent sleep restriction or total sleep deprivation. Individuals who obtained additional sleep exhibited fewer attentional lapses, faster reaction times, and improved mood, although subjective sleepiness often remained high. Preliminary field evidence suggests that preemptive sleep extension enhances workplace safety, reduces errors, and improves sustained attention in shift workers. In athletic contexts, sleep banking has been associated with improved physical endurance and reaction speed. Importantly, this review primarily addresses the homeostatic dimension of sleep regulation (Process S); circadian factors (Process C), including chronotype, social jetlag, and circadian timing of sleep extension and testing, were not systematically addressed in the included studies and represent important limitations of the current evidence base. Overall, sleep banking appears to be a viable strategy for enhancing resilience to acute sleep loss. It confers measurable benefits in performance, cognitive function, and physiological markers, supporting its application in high-demand occupations and competitive environments. Although it does not fully eliminate subjective fatigue, sleep banking may serve as a valuable complement to other fatigue mitigation strategies for anticipated short-term sleep loss. Full article

Background: The aim of this study was to identify patient clusters based on acute symptom profiles and individual characteristics most likely to develop pediatric post-acute sequelae of SARS-CoV-2 infection (PASC), as well as clusters among patients with PASC based on post-acute sequelae and associated characteristics. Methods: This multicenter cohort study in 12 Italian pediatric units enrolled patients aged 0–17 years within three months of a laboratory-confirmed SARS-CoV-2 infection. Participants who completed at least two surveys developed by the ISARIC over one year were analyzed. PASC was defined per WHO criteria. Multiple Correspondence Analysis and Hierarchical Clustering were performed. Results: Of 1137 children enrolled, 850 (76%) completed at least two surveys. The most prevalent age group was older children (6–11 years) (46%); adolescents (12–17) and young children (0–5) were numerically similar. Males were more represented (51.9%), except for the adolescent group (45.1%). PASC occurred in 32.8% of participants, with the distribution of sequelae types varying by age. Clustering in COVID-19 cases identified three clusters: young children mainly presented with respiratory symptoms and with a higher risk of hospitalization, while older children were spared in both acute and post-acute phases. Adolescents, particularly females, reported more pronounced acute symptoms and developed PASC more frequently. Clustering analysis of cases with PASC identified three clusters, confirming these age-related patterns. Young children still exhibited respiratory sequelae, and older children confirmed good recovery with minimal complications, while adolescents, especially females, remained the most affected subgroup, reporting persistent neuropsychological sequelae such as fatigue and insomnia. Conclusions: Findings support age-tailored follow-up, emphasizing respiratory monitoring for young children and targeted neuropsychological care for adolescents, particularly girls. Full article