Search Results (234)

Background: This study aimed to examine the effects of an 8-week plyometric training program on lower-limb explosive strength, jump performance, musculotendinous stiffness, reactive strength index (RSI), and multidirectional speed in elite Polish badminton players. Methods: Twenty-four athletes were randomly assigned to either an experimental group (n = 15), which supplemented their regular badminton training with plyometric exercises, or a control group (n = 15), which continued standard technical training. Performance assessments included squat jump (SJ), countermovement jump (CMJ), single-leg jumps, sprint tests (5 m, 10 m), lateral movements, musculotendinous stiffness, and RSI measurements. Results: The experimental group showed statistically significant improvements in jump height, power output, stiffness, and 10 m sprint and lateral slide-step performance (p < 0.05), with large effect sizes. No significant changes were observed in the control group. Single-leg jump improvements suggested potential benefits for addressing lower-limb asymmetries. Conclusions: An 8-week plyometric intervention significantly enhanced lower-limb explosive performance and multidirectional movement capabilities in young badminton players. These findings support the integration of targeted plyometric training into regular training programs to optimize physical performance, improve movement efficiency, and potentially reduce injury risk in high-intensity racket sports. Full article

Objective: To investigate the effect of an 8-week inspiratory muscle training (IMT) intervention on respiratory muscle strength and cardiovascular autonomic regulation in obese young men. Methods: The study included 36 obese young men who met the inclusion and exclusion criteria. Participants were randomly divided into two groups: the IG (inspiratory muscle training group, n = 17), which underwent high-intensity IMT intervention for 8 weeks, 5 times a week, and the CG (control group, n = 18), which was not given any additional intervention. Assessed parameters included maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR), as well as heart rate variability metrics such as the standard deviation of normal-to-normal intervals (SDNN), root mean square of successive differences (RMSSD), standard deviation of successive differences (SDSD), low-frequency power component (LF), high-frequency power component (HF), and LF/HF ratio. These measurements were taken both at baseline and following the completion of the 8-week intervention period. Results: After 8 weeks of IMT, the MIP and MEP of the IG increased by 31.8% and 26.5%, respectively (p < 0.01). In addition, SBP, DBP, and HR decreased by 2.2%, 3.2%, and 2.1%, respectively (p < 0.01). In the HRV time domain, SDNN and RMSSD increased by 54.1% and 33.5%, respectively (p < 0.01), and there was no significant improvement in SDSD (p > 0.05); in the HRV frequency domain, LF decreased by 40.5%, HF increased by 59.4% (p < 0.01), and the LF/HF ratio decreased by 58.2% (p < 0.05). Conclusion: An 8-week 80%MIP IMT intervention significantly improves respiratory muscle strength and cardiovascular autonomic regulation in obese young men, suggesting that IMT is a promising non-pharmacological strategy for mitigating obesity-related cardiovascular risk. Full article

Background: Resistance training (RT) promotes muscle hypertrophy and strength gains in both men and women. However, sex differences in neuromuscular performance, muscle fiber composition, and the hormonal environment influence strength and power adaptations. While men generally exhibit greater absolute and relative strength, it remains unclear to what extent these differences persist across various load intensities. A better understanding of sex-specific strength and power profiles may help optimize training strategies. The aim of this study was to compare strength and power performance during the bench press exercise in physically active males and females, relative to body mass and fat-free mass (FFM). Methods: Twenty-nine physically active individuals (16 men: 21.3 ± 4.1 years, 13 women: 22.6 ± 4.9 years) performed a one-repetition maximum (1RM) test and an incremental velocity-based assessment at 45%, 55%, 65%, 75%, and 85% of the 1RM using a Smith machine. The barbell velocity was measured via a linear transducer, with the mean propulsive velocity (MPV) recorded for each load. Power-related variables (e.g., peak force [F0], maximal velocity [V0], and maximal power [Pmax]) were analyzed. To account for differences in body composition, data were adjusted for body mass and FFM. Results: Men exhibited significantly greater strength and power than women across most loads when adjusted for both body mass and fat-free mass (FFM) (p < 0.05). These differences were particularly pronounced when normalized to FFM (45–75%1RM; p = 0.001–0.031), with large effect sizes observed (ηp² = 0.185–0.383). Notably, sex differences in mean propulsive velocity (MPV) disappeared at 85%1RM (p = 0.208; ηp² = 0.06), suggesting that maximal neuromuscular recruitment may minimize sex-related disparities at higher intensities. Furthermore, men demonstrated significantly higher values in six of the seven power-related variables, with no significant differences in the %1RM required to achieve an optimal power output. Conclusions: These findings confirm that men exhibit greater strength and power than women, even after adjusting for body composition. However, at high relative loads (≥85%1RM), sex differences in movement velocity appear to diminish, likely due to similar recruitment patterns of high-threshold motor units. These results highlight the importance of sex-specific resistance training programs, particularly in relation to load prescription and the application of velocity-based training methods. Full article

Background: Repeated high-intensity intervals under normoxic (NOR) and hypoxic (HYP) conditions is a training strategy used by athletes. Although different protocols have been used, the effect of longer recovery between repetitions is unclear. In addition, information on the effect of repeated high-intensity intervals on HYP in women is scarce. Aims: To analyse the differences between sexes and between conditions (NOR and HYP) in Repeated Wingate (RW) performance and neuromuscular fatigue in triathletes. Methods: A total of 12 triathletes (men: n = 7, 23.00 ± 4.04 years; women: n = 5, 20.40 ± 3.91) participated in this randomised, blinded, crossover study. In two separate sessions over seven days, participants performed 3 × 30” all out with 7′ of recovery in randomised NOR (fraction of inspired oxygen: ≈20%; ≈300 m altitude) and HYP (fraction of inspired oxygen: ≈15.5%; ≈2500 m altitude) conditions. Before and after RW, vertical jump tests were performed to assess neuromuscular fatigue. Oxygen saturation, power, perceived exertion, muscle soreness and heart rate parameters were assessed. Results: Significant differences were reported between sexes in the parameters of vertical jump, oxygen saturation, RW performance and heart rate (p < 0.05). However, between conditions (NOR and HYP), only differences in oxygen saturation were reported (p < 0.05). No significant differences were reported between conditions (NOR and HYP) in RW performance, neuromuscular fatigue, muscle soreness and perception of exertion. Conclusions: A 3 × 30” RW protocol with 7′ recovery in HYP could have no negative consequences on performance, neuromuscular fatigue and perception of exertion in triathletes compared to NOR, independently of sex. Full article

Background: Soccer performance is largely dependent on high-intensity, unilateral actions such as sprints, jumps, and changes of direction. These demands can lead to strength and power differences between limbs, highlighting the importance of individualised assessment in professional players. Rotational inertial devices offer a valuable method to evaluate and train these mechanical variables separately for each leg. The aim of this study was twofold: (a) to characterise the mechanical variables derived from several lower-body strength exercises performed on rotational inertial devices, all targeting the same muscle group; and (b) to compare the mechanical variables between the dominant and non-dominant leg for each exercise. Methods: Twenty-six male professional soccer players (age = 26.3 ± 5.1 years; height = 182.3 ± 0.6 cm; weight = 75.9 ± 5.9 kg; body mass index = 22.8 ± 1.1 kg/m²; fat mass percentage = 9.1 ± 0.6%; fat-free mass = 68.8 ± 5.3 kg), all belonging to the same professional Belgian team, voluntarily participated in this study. The players completed a single assessment session consisting of six unilateral exercises (i.e., quadriceps hip, hamstring knee, adductor, quadriceps knee, hamstring hip, and abductor). For each exercise, they performed two sets of eight repetitions with each leg (i.e., dominant and non-dominant) in a randomised order. Results: The quadriceps hip exercise resulted in higher mechanical values compared to the quadriceps knee exercise in both limbs (p < 0.004). Similarly, the hamstring hip exercise produced greater values across all variables and limbs (p < 0.004), except for peak force, where the hamstring knee exercise exhibited higher values (p < 0.004). The adductor exercise showed higher peak force values for the dominant limb (p < 0.004). The between-limb comparison revealed differences only in the abductor exercise (p < 0.004). Conclusions: These findings suggest the necessity of prioritising movement selection based on targeted outcomes, although it should be considered that the differences between limb differences are very limited. Full article

This study aimed to describe the training leading to the Zwift Academy (ZA) Finals of a world-class road cyclist who earned a professional contract after winning the contest. Four years of daily power meter data were analyzed (male, 25 years old, 68 kg, VO₂max: 85 mL·min⁻¹·kg⁻¹, and 20-min power: 6.37 W·kg⁻¹), focusing on load, volume, intensity, and strategies. Early training alternated between long, moderate-intensity sessions and shorter high-intensity sessions, with easy days in between. Gradually, the structure was progressively modified by increasing the duration of moderate-intensity (MIT) and high-intensity (HIT) and, subsequently, moving them to “high-volume days”, creating a sort of “all-in days” with low-intensity (LIT), MIT, and HIT. Moderate use of indoor training and a few double low-volume, low-intensity sessions were noted. These data provide a deep view of a 4-year preparation period of ZA, providing suggestions for talent identification and training, thereby highlighting the importance of gradual progression in MIT and HIT. 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

Background: High-intensity actions like accelerations and decelerations, often performed unilaterally, are crucial in elite female football but increase the risk of interlimb asymmetries and injury. Flywheel resistance training enhances eccentric strength, yet limited research has assessed how different inertial loads affect mechanical outputs in unilateral exercises. Purpose: This study investigated how two inertial loads (0.107 kg·m² and 0.133 kg·m²) influence power, acceleration, speed, and asymmetry during unilateral hip extensions in elite female footballers. Methods: Eighteen professional players (27 ± 4 years, 59.9 ± 6.5 kg, 168.2 ± 6.3 cm, BMI 21.2 ± 1.8) completed unilateral hip extensions on a conical flywheel under both inertia conditions. A rotary encoder measured peak/average power, acceleration, speed, and eccentric-to-concentric (E:C) ratios. Bilateral asymmetries between dominant (DL) and non-dominant (NDL) limbs were assessed. Paired t-tests and Cohen’s d were used for analysis. Results: Higher inertia reduced peak and mean acceleration and speed (p < 0.001, d > 0.8). Eccentric peak power significantly increased in the NDL (p < 0.001, d = 3.952). E:C ratios remained stable. Conclusions: Greater inertial loads reduce movement velocity but increase eccentric output in the NDL, offering potential strategies to manage neuromuscular asymmetries in elite female football players. Full article

Boxing is a sport that has a high level of oxygen use within the Rectus Femoris muscle, with recovery between rounds important to subsequent performance. The study aimed to determine muscle oxygen use in male and female professional boxers in response to a repeated sprint stimulus. 10 male (age: 26 ± 5 years, height: 177 ± 4 cm, weight: 72 ± 6 kg) and 6 female (age: 29 ± 4 years, height: 173 ± 2 cm, weight: 73 ± 4 kg) professional boxers took part. Participants attended a single session where a Moxy near-infrared monitor was placed on the rectus femoris muscle of both legs. Participants completed 2 × 30 s Wingate-based sprint efforts with a 60 s active recovery (maintaining 60 rpm against 50 W resistance). Skeletal muscle oxygenation was recorded throughout. Significant differences were found in peak power, average speed and rate of fast desaturation between males and females (p < 0.001) in both sprints. There was a significant difference in males and females for the rate (sprint 1M: −5.6 ± 1.2%.s⁻¹, 1F: −2.3 ± 1.9%.s⁻¹, p < 0.05; sprint 2M: −4.2 ± 1.1%.s⁻¹, 2F: −1.5 ± 0.9%.s⁻¹, p < 0.05) and duration of fast desaturation (sprint 1M: 6.1 ± 1.3 s, 1F: 3.7 ± 2.8 s, p < 0.05; sprint 2M: 7.3 ± 1.6 s, 2F: 4.5 ± 1.0 s, p < 0.05) in both sprints. This study demonstrates that male professional boxers have a significantly different oxygen use and recovery in response to a high-intensity stimulus compared to female boxers. In both male and female boxers, the ability to perform subsequent high-intensity activity is dependent on the quality of the recovery from the initial high intensity activity. Therefore, there is a greater need to focus training to improve recovery kinetics in boxing. Full article

Background: Lower limb motor output contributes to determining functional performance in many motor tasks. This study investigated the effects of non-invasive spinal cord transcutaneous stimulation (scTS) applied during an exercise-based priming protocol on lower limb muscle force and power generation. Methods: Twelve young, physically active male volunteers (age: 22.7 ± 2.1 years) participated in this randomized crossover, sham-controlled study. The maximal voluntary contraction and low-level torque steadiness of knee extensors, as well as the maximal explosive extension of lower limbs, were assessed before and after the priming protocol with scTS or sham stimulation over a total of four experimental sessions. Further, characteristics of evoked potentials to scTS related to spinal circuitry excitability were assessed in the supine position before and after the scTS priming protocol. The exercise component of the ~25 min priming protocol consisted of low-volume, low- and high-intensity lower limb motor tasks. Results: scTS priming protocol tended to increase or maintain maximum isometric torque during knee extension (4.7%) as well as peak force (0.2%) and rate of force development (6.0%) during explosive lower limb extensions, whereas sham priming protocol tended to decrease them (−4.3%, −3.3%, and −15.1%, respectively). This resulted in significant interactions (p = 0.001 to 0.018) and medium–large differences between scTS and sham protocols. These findings were associated with meaningful trends of some neurophysiological variables. Conversely, priming protocols did not affect low-level torque steadiness. Conclusions: scTS counteracted the unexpected fatigue induced by the exercise-based priming protocol, supporting lower limb performance during maximal efforts. Future studies are warranted to assess the implementation of scTS with optimized exercise-based priming protocols during training and rehabilitation programmes that include high-intensity neuromuscular efforts. Full article

Perovskite solar cells (PSCs) are emerging as leading candidates for sustainable energy generation due to their high power conversion efficiencies and low fabrication costs. However, their performance remains constrained by non-radiative recombination losses primarily at grain boundaries, interfaces, and within the perovskite bulk that are difficult to characterize under realistic operating conditions. Traditional methods such as photoluminescence offer valuable insights but are complex, time-consuming, and often lack scalability. In this study, we present a novel Long Short-Term Memory (LSTM)-based deep learning framework for dynamically predicting dominant recombination losses in PSCs. Trained on light intensity-dependent current–voltage (J–V) characteristics, the proposed model captures temporal behavior in device performance and accurately distinguishes between grain boundary, interfacial, and band-to-band recombination mechanisms. Unlike static ML approaches, our model leverages sequential data to provide deeper diagnostic capability and improved generalization across varying conditions. This enables faster, more accurate identification of efficiency limiting factors, guiding both material selection and device optimization. While silicon technologies have long dominated the photovoltaic landscape, their high-temperature processing and rigidity pose limitations. In contrast, PSCs—especially when combined with intelligent diagnostic tools like our framework—offer enhanced flexibility, tunability, and scalability. By automating recombination analysis and enhancing predictive accuracy, our framework contributes to the accelerated development of high-efficiency PSCs, supporting the global transition to clean, affordable, and sustainable energy solutions. Full article

Background: High-intensity intermittent training (HIIT) has been proven to improve cardio-metabolic and respiratory health outcomes. In addition, 20-hydroxyecdysone from plant extracts has been studied for its anabolic effects. However, studies examining these two interventions in individuals who are obese or overweight are limited. This study, thus, examined the effects of HIIT combined with Asparagus officinalis (A. officinalis) extract supplementation on cardiovascular and pulmonary function parameters in obese and overweight individuals. Methods: Seventy-two obese and overweight participants were randomized into four groups (n = 18 each): the control (CON) group; HIIT group (HIIT for 3 days/week); AOE (A. officinalis extract) group (supplementation with 20E at 1.71 mg/kg/day); and HIIT + AOE group. Pre- and 12-week post-intervention measures included heart rate (HR), HR variability, endothelial function, blood pressure (BP), BP variability, pulmonary function and volume, respiratory muscle strength, chest expansion, and body composition. Results: The HIIT + AOE group showed better HR variability with higher high-frequency power and a lower low-frequency/high-frequency ratio (both p = 0.038) compared to the CON group. The peak blood flow increased in both the HIIT (p = 0.03) and HIIT + AOE (p = 0.028) groups, but only the HIIT group had a shorter vascular recovery time (p = 0.048). The maximum expiratory pressure was increased in both the HIIT and HIIT + AOE groups compared to the CON group (p = 0.029 and p = 0.041). The ratio of forced expiratory volume in one second to forced vital capacity, the percent-predicted FEV₁/FVC, and chest wall expansion were higher in the HIIT + AOE group than in the CON group (p = 0.047, p = 0.038, and p = 0.001). The waist-to-hip ratio was lower in the HIIT + AOE group than in the CON group (p = 0.043). There were no significant differences in HR, BP, BP variability, or pulmonary volume parameters among groups. Conclusions: The combination of HIIT with A. officinalis extract supplementation markedly improves HR variability. Moreover, it also greatly improves expiratory muscle strength, chest wall expansion, pulmonary function, and body composition parameters in obese and overweight individuals. Full article

Background/Objectives:Training periodization is fundamental to optimizing athletic performance, with carbohydrate metabolism playing a critical role in supporting high-intensity efforts by facilitating muscle glycogen resynthesis. Recent studies suggest that high carbohydrate diets and high molecular weight carbohydrate (HMWC) supplementation can improve both endurance and anaerobic performance, while potentially influencing oxidative stress. This study investigates the effects of a high carbohydrate diet combined with HMWC supplementation on anaerobic performance and oxidative stress markers in elite swimmers. Methods: Eight national-level swimmers (tier 3–4) completed a three-day training microcycle with dietary interventions. Anaerobic capacity was assessed using Wingate tests for upper and lower limbs, while swimming performance was evaluated through an 8 × 100 m exercise protocol. The study was conducted using a one group quasi-experimental design with a pre-test/post-test structure, with participants acting as their own controls. Baseline measurements were taken prior to the intervention, followed by the administration of the high carbohydrate diet and HMWC supplementation. Post-intervention assessments were performed using the same test protocols to assess changes in performance and oxidative stress markers (such as GSH, CK, MDA, FRAP), which were determined by ELISA. The samples were stored at −80 °C until the evaluations. STATISTICA 5.0 (StatSoft, Inc., 1995) was used for statistical analysis of the obtained results. Results: The obtained results demonstrated significant improvements in peak power output for the lower limbs following supplementation (p < 0.001) and a reduced time to peak power for the upper limbs (p < 0.001). Additionally, velocity during the final swimming segments increased significantly following the intervention (p < 0.001). However, no notable changes were observed in antioxidant enzyme activity (SOD, CAT, GPx, GR) or low molecular weight antioxidants, suggesting a potential ceiling effect in redox adaptations. Lipid peroxidation, measured by MDA levels, increased post-supplementation (p < 0.05), indicating oxidative stress associated with high-intensity training and supplementation. Conclusions: The findings underscore the efficacy of combined dietary strategies with HMWC in enhancing anaerobic performance in swimming, while highlighting the necessity for further exploration of oxidative stress dynamics. Full article

Relevant skills and physiological traits vary between high-intensity functional training (HIFT) workouts, but it is unknown how altering each programming detail affects their importance. To examine the effect of workout duration on relationships to HIFT performance, twelve men and ten women with ≥2 years of HIFT experience (29.3 ± 7.1 years, 171 ± 7 cm, 80.5 ± 15.6 kg) completed a baseline visit to assess body composition and performance in vertical jump, barbell thruster, and 2000 m rowing tests. Participants returned twice to randomly complete the same circuit of rowing, barbell thrusters, and box jumps for “as many repetitions as possible” in 5 or 15 min. Performance was described by expressed kinetics on each exercise, overall and individual exercises, repetition completion rates and volume load completed, and transition times. Spearman correlation analysis revealed several expected relationships (p < 0.05) but also differences between workout durations. Performance measures, especially rowing (time: ρ = −0.89 to −0.94; power: ρ = 0.88 to 0.93), were more applicable to the 5 min workout. Experience and body composition measures (ρ = −0.47 to −0.50) were more often related to the 15 min transition strategy. These data suggest that increasing workout duration alters the importance of relevant predictive traits. Full article

Background/Objectives: Beetroot juice (BJ), a natural source of dietary nitrate, has gained increasing attention for its potential to improve exercise performance and cardiovascular function. While its benefits are well documented in endurance contexts, less is known about its short-term effects on resistance training performance and recovery. Thus, this study investigated the effects of short-term BJ supplementation on strength performance, cardiovascular responses, muscle oxygenation, and post-exercise recovery in resistance-trained males. Methods: Twelve healthy men (age: 21.3 ± 1.9 years; body mass index: 21.42 ± 2.36 kg/m²) completed two supplementation protocols involving BJ, providing 450 mg of nitrate per day, and a nitrate-free placebo (PLA). Each protocol consisted of two laboratory visits, one to assess the acute ergogenic effects and another to evaluate recovery after 72 h, resulting in a total of four sessions over a two-week period. During the three consecutive days of supplementation, participants ingested a single 900 mL dose (15 g BJ powder/PLA) 2 h before the first session, followed by three daily 300 mL doses (5 g BJ each/PLA) over the next two days, and a final dose (15 g BJ powder/PLA) taken 2 h before the second session (72 h post-first session). Each testing session involved incremental back squat (BS) and bench press (BP) exercises at 60%, 70%, and 80% of the one-repetition maximum (1RM) performed to failure, with three-minute rest intervals between sets. Repetition to failure, movement velocity, peak power, peak heart rate (HR), and muscle oxygenation (SmO₂) were recorded during BP and BS exercises. Heart rate variability (HRV) and blood lactate were assessed before and after each training session. Lower-limb strength (CMJ and SJ) and delayed-onset muscle soreness (DOMS) were assessed daily during the 3-day supplementation period. Results: BJ significantly increased repetitions completed at 80% 1RM during BP and BS (p < 0.05) compared to the PLA. Peak movement velocity improved across all intensities using BJ with higher values compared to the PLA at 60–80% 1RM (p < 0.05). SmO₂ was higher in BJ at 70–80% 1RM) and further improved after 72 h of BJ supplementation (p < 0.05). Cardiovascular strain was reduced in BJ, evidenced by lower peak HRs and smaller post-exercise declines in HRV indices (p < 0.05). Post-exercise recovery favored BJ, with faster recovery in jump performance at 24 h and reduced upper-limb DOMS at 24–48 h (p < 0.05). Conclusions: Short-term BJ supplementation enhances high-intensity resistance performance, improves muscle oxygenation, attenuates cardiovascular strain, and accelerates neuromuscular recovery. These benefits highlight its potential as a practical strategy for athletes seeking to optimize training performance and recovery during periods of intense resistance training. Full article