Search Results (392)

High-intensity/sprint interval training (HIIT/SIT) improves aerobic and anaerobic performance, but it is unknown if HIIT/SIT increases strength, muscle mass/size, and muscle endurance (ME). We aimed to determine if HIIT/SIT increases strength, muscle mass/size, and ME. Databases (Ovid Medline, Sport Discus, EMBASE, and CINAHL) and the gray literature (Google Scholar) were searched for original research articles investigating the impact of HIIT/SIT on strength, muscle mass/size, and ME (23 March 2025). The risk of bias (ROB) was assessed via the Cochrane ROB 2 Tool. Meta-analyses were performed when three or more randomized controlled trials compared HIIT/SIT to a common comparator. Fifty-four studies were included (N = 1136). Twenty-five studies had a high ROB, while twenty-nine had some concerns. Standardized mean differences (SMD) (95% CI) of 0.16; (−0.09, 0.40), 0.33; (−0.21, 0.87) were observed for meta-analyses comparing the effect of HIIT/SIT to moderate intensity continuous training (MICT) and non-exercise controls (CON) on FFM, respectively. A meta-analysis comparing the effect of HIIT/SIT to resistance training (RT) on leg press strength yielded a SMD of −0.82; 95% CI: (−1.97, 0.33). HIIT/SIT may induce slightly greater gains than MICT and CON for FFM, while RT is likely superior to HIIT/SIT for improving leg press strength. However, the certainty of evidence is low, and 95% CIs intersect zero for all analyses. Full article

Background/Objectives: This study aimed to identify the functional adaptations that enable competitive performance in a Paralympic cyclist with optimized bilateral transtibial prostheses compared to a conventional cyclist. Additionally, it describes the development of the prosthesis, designed through a user-centered engineering process incorporating Quality Function Deployment (QFD), Computer-Aided Design (CAD), Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD), and topological optimization, with the final design (Design 1.4) achieving optimal structural integrity, aerodynamic efficiency, and anatomical fit. Methods: Both athletes performed a progressive cycling test with 50-watt increments every three minutes until exhaustion. Cardiorespiratory metrics, lactate thresholds, and joint kinematics were assessed. Results: Although the conventional cyclist demonstrated higher Maximal Oxygen Uptake (VO₂max) and anaerobic threshold, the Paralympic cyclist exceeded 120% of his predicted VO₂max, had a higher Respiratory Exchange Ratio (RER) [1.32 vs. 1.11], and displayed greater joint ranges of motion with lower trunk angular variability. Lactate thresholds were similar between athletes. Conclusions: These findings illustrate, in this specific case, that despite lower aerobic capacity, the Paralympic cyclist achieved comparable performance through efficient biomechanical and physiological adaptations. Integrating advanced prosthetic design with individualized evaluation appears essential to optimizing performance in elite adaptive cycling. Full article

Heterotrophic nitrification and aerobic denitrification (HN–AD) is an emerging biological process capable of achieving efficient nitrogen removal in a single reactor. This study investigates the HN–AD performance of a sequencing batch reactor (SBR) operated with a simple anaerobic–aerobic cycle for treating high C/N wastewater. Over a 220-day operation, the system achieved average removal efficiencies of 98.6% for COD, 93.3% for NH₄⁺-N, and 87.1% for total nitrogen. Effluent concentrations of NO₂⁻-N and NO₃⁻-N remained negligible at the end of each aerobic phase. Concentration profiles of NH₄⁺-N, NO₂⁻-N, and NO₃⁻-N throughout the operation cycles confirmed the occurrence of simultaneous nitrification and aerobic denitrification. The consistently high COD removal and robust nitrogen reduction highlight the stability of the HN–AD microbial consortia enriched from activated sludge. Phosphorus removal (average removal efficiency 66.3%) may be enhanced by increasing the activity of phosphate-accumulating organisms (PAOs) through process optimization. This study demonstrated effective HN–AD using activated sludge in SBRs. Future work will focus on evaluating the system with real wastewater and continuous-flow setups to further refine operational parameters for sustained HN–AD performance. Full article

With increasing wastewater treatment demands and decarbonization goals, synergistic reduction in pollutants and green house gas (GHG) emissions is crucial. High process emissions like N₂O pose significant challenges, yet optimized carbon reduction strategies for conventional plants are lacking. This study developed three mathematical models to quantify the impact of dissolved oxygen (DO), influent salinity, and C/N ratio on direct emissions (CH₄, N₂O) and indirect emissions. Response Surface Methodology (RSM) optimized these factors to minimize GHG emissions under three accounting scenarios: (1) plants with CH₄ reuse systems: salinity = 0.5 g L⁻¹, DO = 3.67 mg L⁻¹, C/N = 12.75; (2) plants focusing solely on direct emissions: salinity = 0.5 g L⁻¹, DO = 3.35 mg L⁻¹, C/N = 3; and (3) plants assessing total emissions: salinity = 0.5 g L⁻¹, DO = 2.5 mg L⁻¹, C/N = 7.18. Key findings indicated that increasing salinity exacerbated greenhouse gas emissions. Elevated DO levels in the aerobic stage reduced N₂O emissions but increased indirect emissions in the A²/O process. Higher C/N ratios promoted anaerobic CH₄ production, but sufficient carbon reduced N₂O by enabling complete heterotrophic denitrification. A 60−day continuous GHG emissions monitoring campaign was conducted at a WWTP to validate the actual emission reductions achievable under the identified optimal control conditions. An analysis and comparison of operational and economic costs were also performed. The findings provide practical insights into sustainable GHG emission management and offer potential solutions to advance the synergistic reduction in GHG emissions and pollutants. Full article

Background: Chronic chlorella intake combined with high-intensity intermittent training (HIIT) has been shown to accelerate aerobic and anaerobic capacities in rodents. This study aimed to clarify the effects of combining chlorella intake with short-term HIIT on exercise performance in humans, and to investigate the impact of chlorella intake on cardiac adaptation. Materials and Methods: In Study 1, twelve healthy young men completed a 3-week exhaustive HIIT, comprising 6–7 bouts of 20 s of cycling on a leg ergometer at an intensity of 170% maximal oxygen uptake ($\dot{\mathrm{V}}$O_2max), with a 10 s rest between each bout, 3 days/week. They were orally administered either placebo or chlorella during the 3 weeks in a double-blinded, randomized crossover trial (RCT). In Study 2, six healthy young men were orally administered either placebo or chlorella during 4 weeks in a double-blinded, placebo-controlled RCT. We measured $\dot{\mathrm{V}}$O_2max and cardiac function (stroke volume [SV], heart rate [HR], and cardiac output [CO]) during maximal exercise. In Study 3, chlorella-induced changes in molecular markers of maladaptation of the heart were measured in healthy rats. Results: [Study 1] After each HIIT, $\dot{\mathrm{V}}$O_2max significantly increased in the placebo and chlorella groups (p < 0.05). Changes in $\dot{\mathrm{V}}$O_2max were significantly higher in the chlorella group than in the placebo group (p < 0.05). [Study 2] Changes in SV and CO during maximal exercise were significantly higher in the chlorella group than in the placebo group (p < 0.05 each), but HR_max did not change. [Study 3] Chronic chlorella intake did not change the molecular markers of pathological cardiac hypertrophy. Conclusions: Chronic chlorella intake, which improves aerobic capacity by enhancing cardiac function without causing cardiac maladaptation, combined with short-term HIIT, further enhanced aerobic capacity. Thus, the chlorella-induced increase in cardiac function may further enhance aerobic capacity through HIIT. Full article

The main research question of this review involved the identification of the various physiological and physical determinants of flat-water kayaking. A systematic search was conducted using three databases (PubMed, Google Scholar, and Microsoft Academic) between 1991 and December 2022. Quality assessment was performed using a version of the National Heart, Lung and Blood Institute checklist tailored for cross-sectional and observational studies. A total of 169 articles were identified in the initial screening. After duplicate removal and further screening for relevance, a total of 17 articles were included in the review. Altogether, it was found that flat-water kayaking performance was strongly correlated with maximum oxygen uptake (VO_2max), aerobic and anaerobic thresholds, peak aerobic and anaerobic capacity measure in lab and on the water, and upper and lower-body strength and power, which were measured using heavy resistance, as well as isometric and isokinetic implements. What is less clear is the association between total lean mass and flat-water kayaking performance. However, this may largely be due to the differences in when the measurements were taken. Full article

Background: Chronic heart failure (HF) is a systemic condition in which the heart is unable to meet the body’s peripheral demands, leading to both acute and chronic functional decline, accompanied by high morbidity and mortality rates. A non-pharmacological, non-surgical standard approach to managing HF is cardiovascular rehabilitation, which is widely endorsed by international cardiology societies. This typically includes aerobic and anaerobic physical activity involving the peripheral skeletal muscles. However, international guidelines often overlook the clinical significance of the diaphragm and the role of inspiratory muscle training (IMT) in rehabilitation. The diaphragm plays a critical role not only in respiratory and cardiac function but also in supporting limb movements and overall physical performance. In patients with HF, diaphragmatic dysfunction contributes significantly to the symptoms they experience. Conclusions: This review highlights the need for a greater emphasis on incorporating IMT into the standard rehabilitation protocols for patients with HF, given its potential to improve both respiratory function and overall physical capacity. Full article

The aim of this systematic review was to examine the effects of high-intensity interval training (HIIT) on physical performance and body composition in female basketball players. The review followed PRISMA guidelines, and the protocol was registered in the PROSPERO database (registration number: CRD420251006285). A comprehensive search was conducted across PubMed, Scopus, Web of Science, and Google Scholar. Nine studies that met the inclusion criteria were analyzed, with intervention durations ranging from 4 to 12 weeks. Despite differences in protocols, a majority of studies reported improvements in VO_2max (6/9), explosive strength (7/9), agility (5/6), and speed (5/6) and reductions in body mass and fat percentage (3/3). These findings highlight HIIT as an effective method for enhancing both aerobic and anaerobic capacities, as well as optimizing body composition. Despite variations in study protocols, HIIT consistently offers improvements in performance, irrespective of training level. The results underscore the importance of HIIT in preparing athletes, not only during the preseason but also throughout the competition period. Coaches should consider integrating HIIT into training programs, adjusting intensity and volume based on the season to optimize performance and prevent overtraining. Full article

Background: Premature ventricular contractions (PVCs) are common arrhythmias associated with symptoms such as fatigue and, in severe cases, PVC-induced cardiomyopathy. Catheter ablation (CA) is a primary treatment for symptomatic PVCs, particularly when pharmacological therapies fail or are undesired. While improvements in: quality-of-life following ablation are documented, its impact on functional capacity remains underexplored. Objectives: This study evaluated the impact of CA on functional capacity and cardiac stress markers in patients with symptomatic PVCs using cardiopulmonary exercise testing (CPET) and NT-proBNP levels. Methods: A total of 30 patients underwent successful PVC ablation and completed baseline and follow-up CPET evaluations under the Bruce protocol. PVC burden, left ventricular ejection fraction (LVEF), NT-proBNP levels, and CPET parameters, including VO₂ max, METS, ventilatory efficiency, and anaerobic threshold (AT), were analyzed pre- and post-ablation. Results: PVC burden significantly decreased post-ablation (23,509.3 ± 10,700.47 to 1759 ± 1659.15, p < 0.001). CPET revealed improved functional capacity, with VO₂ max increasing from 24.97 ± 4.16 mL/kg/min to 26.02 ± 4.34 mL/kg/min (p = 0.0096) and METS from 7.16 ± 1.17 to 7.48 ± 1.24 (p = 0.0103). NT-proBNP significantly decreased (240.93 ± 156.54 pg/mL to 138.47 ± 152.91 pg/mL, p = 0.0065). LVEF and ventilatory efficiency metrics (VE/VO₂ and VE/VCO₂) remained stable. Conclusions: Catheter ablation improves functional capacity, reduces cardiac stress, and minimizes medication dependency in patients with symptomatic PVCs. These findings support the utility of ablation in enhancing aerobic capacity and overall exercise performance. Full article

Viribay and colleagues published a meta-analysis called “Effects of Arginine Supplementation on Athletic Performance Based on Energy Metabolism: A Systematic Review and Meta-Analysis” in Nutrients in May of 2020. This meta-analysis sought to quantify the effects of arginine supplementation on aerobic and anaerobic performance outcomes. In the course of conducting this analysis, the researchers made multiple errors that are common among meta-analyses in the field of sports nutrition. This comment discusses how these issues impact the results and interpretation of the paper, and how individuals who are interpreting or conducting sports nutrition meta-analyses in the future can identify or avoid similar errors. Full article

Poor sleep quality and insomnia are increasingly linked to chronic inflammation and obesity-related metabolic dysfunction. Aerobic exercise is a promising non-pharmacological approach for enhancing sleep quality and reducing systemic inflammation; Therefore, we aim to systematically evaluate and quantify the effects of aerobic exercise interventions on subjective sleep quality, insomnia severity, and circulating markers (IL-6 and TNF-α) in adults. A systematic search was conducted in institutional databases (UNAM, UACJ) and PubMed to identify randomized controlled trials (RCTs) examining the effects of exercise on sleep and inflammation. Risk of bias was assessed using the Cochrane RoB2 tool. Meta-analyses were performed using RevMan 5.4 with random-effects models to estimate pooled mean differences (MD) and standardized mean differences (SMD), with 95% confidence intervals. Anaerobic protocols were excluded from the meta-analysis due to the insufficient availability of data. : Eleven RCTs met the inclusion criteria. Aerobic exercise showed a significant pooled effect on sleep outcomes (MD = −2.51; 95% CI: −4.80 to −0.23; p = 0.03). However, subgroup analyses for Pittsburgh Sleep Quality Index (PSQI) (MD = −2.27; p = 0.15) and Insomnia Severity Index (ISI) (MD = −2.98; p = 0.16) were not statistically significant. Two studies on IL-6 reported a non-significant reduction (SMD = −0.17; p = 0.66), with moderate heterogeneity. TNF-α results were also non-significant (SMD = 0.60; p = 0.29) with substantial variability. Our results showed that aerobic exercise may modestly improve sleep outcomes; however, current evidence does not support its effectiveness in reducing levels of IL-6 or TNF-α. Further well-controlled trials are needed to clarify its immunometabolic effects, particularly in populations with obesity or metabolic disorders. Full article

The purpose of this non-randomized study was to determine the effect of strength training and aerobic interval training on the anaerobic and aerobic power and endurance of young men (assessed by determination of the second ventilatory threshold (VT2)) in non-trained men. Participants (n = 45) were recruited into three groups of 15 each. The first group performed strength training (ST), the second performed aerobic interval training (AIT), and the third group was the control group (CON). In each group, somatic measurements and tests of aerobic (graded test with VT2 determination) and anaerobic capacity (Wingate test) were performed twice (before and after the exercise intervention in the training groups). In the graded test, the level of maximal load (Pmax), maximal oxygen uptake (VO₂max) and intensity and oxygen uptake at VT2 were determined. In the Wingate test, peak power (PP) and mean power (MP) were determined. The exercise intervention in the ST and AIT groups lasted 6 weeks, with three workouts per week. Training in the ST and AIT groups resulted in significant increase in absolute Pmax (p < 0.001, ES = 0.52 and p < 0.05, ES = 0.36), VO₂max (p < 0.001, ES = 0.50 and p = 0.02, ES = 0.55) in the participants. Only AIT was significantly effective in improving oxygen uptake at VT2 (p < 0.04, ES = 0.64), and ST in improving PP. Strength training can be an effective training method in training aerobic and anaerobic capacity (significantly increases Pmax, VO₂max, and PP), while it does not significantly affect work intensity at VT2. Our results suggest that, particularly in anaerobic–aerobic sports, strength training may be a training method that can simultaneously improve both anaerobic power and maximal oxygen uptake. It can also complement endurance training. Full article

Objectives: The aim of this study was to indicate which variables are the most important determinants of swimming results in the 50 m front crawl among non-elite pre-pubertal female swimmers. Methods: The study group consisted of 14 female swimmers (at the time of the research commencement—biological age: 10.52 ± 0.37 years; body mass: 34.99 ± 2.77 kg; height: 146.00 ± 3.05 cm). The study was conducted over three years. The swimmers performed capacity training recommended by the British Swimming Federation. Every 6 months, in the participants the following parameters were measured: percentage of body fat; anthropometric measurements; aerobic and anaerobic capacity; and respiratory parameters: vital capacity—VC, forced expiratory volume—FEV1, and forced vital capacity—FVC. Additionally, a 50 m front crawl swim test was performed. Results: After adjusting for multicollinearity, the most influential determinants of swimming performance were anthropometric measures: shoulder width was the most influential predictor, with a regression coefficient of −0.66, followed by foot length (with a beta of −0.15) and chest depth (with a beta of 0.008). The remaining anthropometric and physical predictors did not contribute to the prediction of 50 m freestyle performance. Conclusions: These research results suggest to coaches and trainers that sports performance in sprint distances in pre-pubertal girls is not determined by aerobic and anaerobic capacity or body fat but is based on the somatic build of the swimmer. Full article

Mechanical–biological treatment plants face challenges in effectively separating organic fractions from residual municipal solid waste for biological treatment. This study investigates the optimization measures carried out at the Erbenschwang MBT facility, which transitioned from solely aerobic treatment to integrated anaerobic digestion using a screw press. This study focused on evaluating the efficiency of each mechanical pretreatment step by investigating the composition of the residual waste, organic fraction recovery rate, and screw press performance in recovering organic material and biogas to press water. The results showed that 92% of the organic material from the residual waste was recovered into fine fractions after shredding and trommel screening. The pressing experiments produced high-quality press water with less than 3% inert material (0.063–4 mm size). Mass balance analysis revealed that 47% of the input fresh mass was separated into press water, corresponding to 24% of the volatile solids recovered. Biogas yield tests showed that the press water had a biogas potential of 416 m³/ton VS, recovering 38% of the total biogas potential. In simple terms, the screw press produced 32 m³ of biogas per ton of mechanically separated fine fractions and 20 m³ per ton of input residual waste. This low-pressure, single-step screw press efficiently and cost-effectively prepares anaerobic digestion feedstock, making it a promising optimization for both existing and new facilities. The operational configuration of the screw press remains an underexplored area in current research. Therefore, further studies are needed to systematically evaluate key parameters such as screw press pressure (bar), liquid-to-waste (L/ton), and feed rate (ton/h). Full article

Background/Objectives: This study aimed to evaluate the effects of four weeks of combined Acetyl-l-Carnitine and alpha-lipoic acid (ALA) supplementation on anaerobic and aerobic performance and fatigue resistance in trained cyclists, hypothesizing improvements in maximal aerobic power (MAP), Wingate test performance, and reduced lactate accumulation. Methods: In a double-blind, randomized trial, 41 male trained cyclists (age: 36 ± 12 years; MAP: 4.35 ± 0.60 W·kg⁻¹) were assigned to a supplement group (SUP, n = 19; 1200 mg/day Acetyl-l-Carnitine, 300 mg/day ALA, 1.1 mg Vitamin B1, 2.5 µg Vitamin B12) or placebo group (PLA, n = 22) for four weeks. Performance was assessed pre- and post-intervention via counter-movement jumps (CMJs), Wingate tests (WG₁, WG₂), and a graded exercise test (GXT). Blood lactate ([La⁻]) was measured post-Wingate. A three-way mixed ANOVA analyzed Wingate performance (session, order, and group), and a two-way ANOVA assessed MAP and fatigue effects. Results: MAP increased by 3.4% (314 ± 32 W to 324 ± 37 W; p = 0.005) with no group interaction (p = 0.457). Wingate peak power showed main effects for order (p < 0.001) and session (p = 0.011) but no group interaction (p = 0.676). SUP reduced [La⁻] by 1.5 mmol·L⁻¹ post-WG₂ in POST (p = 0.049). No significant group differences were found for CMJ or fatigue metrics. Conclusions: Four weeks of Acetyl-l-Carnitine and ALA supplementation did not enhance aerobic or anaerobic performance in trained cyclists, despite reducing blood lactate after high-intensity exercise, suggesting no ergogenic benefits. Full article