Interindividual differences in physical function and their impact on regular player selection among junior high school soccer athletes.

[Purpose] Unlike professional teams that use comprehensive evaluations, player selection in local and school-level soccer teams relies on the coaches' practical experience. This study investigated the differences in physical function between regular and non-regular male junior high school soccer players to provide valuable insights into player selection. [Participants and Methods] We assessed grip strength, rebound jumps, muscle strength, agility, short-distance running, anaerobic power, and countermovement jumps in 55 Japanese junior high school boys, who were divided into regular (R) and non-regular (NR) groups. Moreover, the age, height, and weight of the groups were compared. [Results] The analysis revealed significant differences in countermovement jumps and anaerobic power, while accounting for age and physique. [Conclusion] These results suggest that countermovement jumps and anaerobic power may constitute determining factors for regular and non-regular players, even when age and physical characteristics are considered.

Taurine supplementation enhances anaerobic power in elite speed skaters: A double-blind, randomized, placebo-controlled, crossover study.

Taurine (2-aminoethanesulfonic acid) is a semi-essential sulphur-containing amino acid abundant in skeletal muscle. Taurine supplementation is popular among athletes and has been purported to enhance exercise performance. This study aimed to investigate the ergogenic effects of taurine supplementation on anaerobic (Wingate; WanT) performance, blood lactate, ratings of perceived exertion (RPE), and countermovement vertical jump (CMJ) in elite athletes. For this study, randomized, double-blind, placebo-controlled crossover designs were used. Thirty young male speed skaters were randomly assigned to either taurine (TAU; single dose of 6 g) or placebo (PLAC; single dose of 6 g) 60 minutes before testing. Following a 72-hour washout, period participants completed the opposite condition. TAU improved peak (Δ% = 13.41, p < 0.001, d = 1.71), mean (Δ% = 3.95, p = 0.002, d = 1.04), and minimum power output (Δ% = 7.89, p = 0.034, d = 0.48) compared to placebo. Further, RPE (Δ% = -10.98, p = 0.002, d = 0.46) was significantly lower following the WanT in the TAU condition compared to placebo. There were no differences between conditions for the countermovement vertical jump. In conclusion, acute TAU supplementation augments anaerobic performance in elite speed skaters.

The effects of taurine ingestion on anaerobic and physiological performance in female rugby players.

The purpose of this study was to investigate the acute effect of low, moderate, or high doses of taurine on anaerobic and physiological performance in female rugby players. A total of 16 sub-elite female rugby athletes (21.3 ± 1.5 yr, 168.0 ± 4.9 cm, 62.1 ± 3.5 kg mean ± SD) participated in this research. Following familiarization, participants attended 4 successive tests separated by 72 h in a randomized, counter-balanced, crossover research design. Following an over night fast, participants completed a 5-min 60 Watt warm-up followed by a 30-s Wingate anaerobic test on a cycle ergometer after ingestion of either 2 g taurine (LOWTAU), 4 g (MODTAU), 6 g (HIGHTAU) or placebo (PLA) 1 h before the test. Peak (PP) and mean power (MP) along with heart rate (HR), rating of perceived exertion (RPE), capillary lactate and blood glucose were measured. LOWTAU did not affect PP, MP, HR, lactate and glucose compared to PLA (p > 0.05), while MODTAU improved MP and HIGHTAU improved PP and MP compared to PLA and LOWTAU (p < 0.05). MODTAU and HIGHTAU had little effect on HR, blood lactate and glucose (p > 0.05). A single dose of taurine (MODTAU or HIGHTAU) 1 h prior to competition or training would provide an ergogenic effect on subsequent power output.

The effect of eight weeks beetroot juice supplement on aerobic, anaerobic power, and field performance of soccer players.

The purpose of the study investigated the effect of eight weeks of soccer training with beetroot juice supplement on aerobic power, anaerobic power, and field performance of soccer players. This is experimental research, by the control group in pre and post-test. The statistical population was male soccer players. Forty subjects were randomly divided into four groups including the exercise group (EX) the exercise group with beetroot juice supplement (EX&BRJS) the beetroot juice supplement group (BRJS), and the control group (C). Aerobic power, anaerobic threshold, and respiratory exchange ratio, measured by the gas analyser (Cosmed), anaerobic power (peak, mean power), and fatigue index, by Wingate cycle test (Monark, 839), and field performance by (Bangsbo, field test performance). The statistical methods include the Kolmogorov-Smirnov, Levin, covariance (ANCOVA), and pair comparison with Bonferroni test. The results showed eight weeks' of soccer training with beetroot juice supplement, significantly changed aerobic power, respiratory exchange ratio, anaerobic threshold, anaerobic power, field performance, and fatigue index (P ≤ 0.05). Additionally, in all variables, the paired comparison showed that the EX&BRJS group progressed more than all other condition groups. The soccer athletes may use beetroot juice supplements along with soccer exercises to improve aerobic and anaerobic power and field performance.

Response to Three Weeks of Sprint Interval Training Cannot Be Explained by the Exertional Level.

Background and Objectives: The all-out mode of sprint interval training (SIT) has been shown to be an efficient method for improving sports performance, exercise capacity, and aerobic fitness. Although the benefits of SIT are well described, the mechanisms underlying the different degrees of response remain largely unexplored. We aimed to assess the effects of exertion on the responsiveness to SIT. Materials and Methods: The participants were 28 young untrained men (mean ± SD age 25.7 ± 6.03 years) who exhibited either a large or small increase in Wingate test average power in response to nine SIT sessions performed over three weeks. Each training session comprised four-six bouts of 30 s all-out cycling interspaced with 4 min of rest. Individual responses were assessed using heart rate (HR) during exercise for all nine sessions, as well as blood lactate concentration up to 1 h, and the decrement in maximal voluntary knee extension torque (MVC) up to 24 h after the first and last training sessions. Peak oxygen uptake (VO2peak) and maximum HR were measured before and after training during an incremental cycling test to exhaustion. Results: Although all participants showed benefits of SIT such as increased VO2peak, the increase in anaerobic cycling power varied between participants. We identified 17 high responders and nine low responders, whose average power outputs were 0.80 ± 0.22 and 0.22 ± 0.19 W/kg, respectively. The HR achieved during any of the training sessions did not differ between high and low responders. The lactate kinetics did not differ between groups before and after the intervention. Training resulted in a more rapid recovery of MVC without any discernible differences between the high and low responders. Conclusion: The differences in the responses to SIT are not dependent on the exertion level during training.

Effect of skill-based training vs. small-sided games on physical performance improvement in young soccer players.

Recently, there has been increasing attention to research related to the effect of skill-based or game-based training on soccer players' physical performance. Therefore, this study aimed to compare the effectiveness of skill-based training (SBT) at maximum intensity versus the small-sided game (SSG) on the physical performance characteristics of young soccer players during the pre-season period. Twenty-two male soccer players (mean age 15.3 ± 3 years) were randomly assigned to either an SBT or SSG fully controlled intervention programme, running parallel for eight weeks and held twice a week. On three non-consecutive days before and after training players completed a test battery consisting of the 20 m sprint, T-run, countermovement jump, running anaerobic sprint test (RAST) and 20 m shuttle run. Data were analysed with a two-way ANOVA test for repeated measures. SBT and SSG interventions induced a significant improvement in the anaerobic power (10.9% vs 6.2%), explosive power (8.5% vs 5.6%), VO2max (6.7% vs 6.5%) and vertical jump (5.3% vs 2.9%), respectively. When the improvements in the physical performance variables of both groups are compared, the SBT group achieved greater improvement than the SSG group in anaerobic power (by 4.7%), in explosive power (by 2.8%), in vertical jumping (by 2.3%), in the 20 m sprint (by 2.2%) and T-test scores (by 1.7%). However, improvements in the VO2max were similar in both groups. The results of the present study suggest that SBT at maximum intensity may be more effective than SSG in improving the physical performance characteristics of young soccer players in the pre-competitive season.

Effects of short-term Rhodiola Rosea (Golden Root Extract) supplementation on anaerobic exercise performance.

The purpose of this study was to examine the effects of short-term Rhodiola Rosea (Golden Root Extract (GRE)) supplementation on repeated Wingate performance. Eleven physically active college aged females were recruited for this study. In a within groups counterbalanced study design, participants were supplemented with either 1,500 mg/day of GRE or placebo (gluten-free cornstarch) for 3 days. Participants also took an additional 500 mg dose of corresponding treatment 30 minutes prior to testing of each trial. During each exercise trial, participants completed 3 × 15-second Wingate Anaerobic Tests (WAnTs) separated by 2-minute active recovery periods. Each exercise trial was separated by a 7 day washout period. Over the 3 × 15-second WAnTs, mean watts (p = 0.017, ES = 0.55), mean anaerobic capacity (p = 0.025, ES = 0.96), mean anaerobic power (p = 0.03, ES = 1.07), mean peak watts (p = 0.029,ES = 0.46), and mean total work (p = 0.017, ES = 0.49) were higher in the GRE treatment trial versus placebo. However, mean fatigue index (p = 0.094, ES = 0.39) was unaffected regardless of treatment. Our results show that GRE supplementation enhanced anaerobic exercise performance as measured through repeated WAnTs. GRE may possess ergogenic benefits and findings hold important implications for boosting anaerobic performance in repeated anaerobic bouts of exercise.

The 2 Minute Loaded Repeated Jump Test: Longitudinal Anaerobic Testing in Elite Alpine Ski Racers.

This study investigated the 4-year development of anaerobic power and capacity in Austrian elite female alpine ski racers and examined the relationship between the 2-minute loaded repeated jump test (LRJT) results and ski racing performance (International Ski Federation (FIS) points). Ten Austrian elite female ski racers were tested prior to four racing seasons. The LRJT consisted of 48 loaded countermovement jumps (LCMJs) with barbell load equivalent to 20% bodyweight. Before the LRJT, maximal body mass normalized average power of a single LCMJ (PMAX) was determined. The mean jump power was calculated across all jumps in the test (P0-120). Anaerobic power (PMAX) in season 2 (32.3 ± 2.3 W·kg-1) significantly improved over season 1 (30.5 ± 2.3 W·kg-1) (p < 0.05) but there were no further differences between seasons, with season 3 at 33.5 ± 3.4 W·kg-1 and season 4 at 33.6 ± 3.0 W·kg-1. Anaerobic capacity (P0-120) increased up to season 3 by 9.2% (27.1 ± 2.8 to 29.6 ± 2.4 W·kg-1), but was significantly higher only when comparing season 4 to seasons 1 and 2 (p < 0.05). FIS points changed significantly (p < 0.05), from 18.1 ± 8.2 in season 1 to 8.4 ± 4.8 in season 4 (lower FIS points indicates better racing results). FIS points had a positive relationship with PMAX (r = -0.73, p < 0.05) and P0-120 (r = -0.64, p < 0.05) only in season 4. Improvements in FIS points from year to year did not correlate with seasonal increases in LRJT results. In conclusion, anaerobic power improved only after season 1, and anaerobic capacity changes were evident only in season 4. Ski racing performance (FIS points) correlated with LRJT test results in only season 4. The LRJT can monitor a ski racer's anaerobic power and capacity, but does not correlate with ski racing performance.

Correcting Vitamin D Insufficiency Improves Some But Not All Aspects of Physical Performance During Winter Training in Taekwondo Athletes.

We investigated the effects of vitamin D3 supplementation on physical performance during winter training in vitamin D insufficient taekwondo athletes. Thirty-five collegiate male and female taekwondo athletes, aged 19-22 years with low serum 25(OH)D concentration (28.8 ± 1.10 nmol/L), were randomly assigned to a vitamin D group (n = 20) or a placebo group (n = 15). Subjects received either a vitamin D3 capsule (5,000 IU/day) or a placebo during 4 weeks of winter training. Blood samples were collected for analyzing serum 25(OH)D concentration. Physical performance tests included Wingate anaerobic test, isokinetic muscle strength and endurance, a countermovement jump test, sit-ups, agility test, and 20-m pacer. Serum 25(OH)D concentrations increased significantly in the vitamin D group (96.0 ± 3.77 nmol/L) after 4 weeks of supplementation, but no changes were found in the placebo group (F = 242.44, p = .000). There were significant interaction effects for anaerobic peak power (F = 7.49, p = .010) and isokinetic knee extension at 180 deg/s (F = 6.08, p = .019). Changes in serum 25(OH)D concentration were positively associated with changes in peak power and isokinetic knee extension at 180 deg/s. However, no significant interaction effects were observed in other performance variables. This study suggests that 4 weeks of vitamin D supplementation elevates serum 25(OH)D concentration to sufficient levels. Correcting vitamin D insufficiency improves some but not all aspects of performance. Thus, efficacy of vitamin D supplementation to enhance performance remains unclear.

Effects of work-matched moderate- and high-intensity warm-up on power output during 2-min supramaximal cycling.

We tested the hypothesis that compared with a moderate-intensity warm-up, a work-matched high-intensity warm-up improves final-sprint power output during the last 30 s of a 120-s supramaximal exercise that mimics the final sprint during events such as the 800-m run, 1,500-m speed skate, or Keirin (cycling race). Nine active young males performed a 120-s supramaximal cycling exercise consisting of 90 s of constant-workload cycling at a workload that corresponds to 110% peak oxygen uptake (VO2peak) followed by 30 s of maximal cycling. This exercise was preceded by 1) no warm-up (control), 2) a 10-min cycling warm-up at a workload of 40% VO2peak (moderate-intensity), or 3) a 5-min cycling warm-up at a workload of 80% VO2peak (high-intensity). Total work was matched between the two warm-up conditions. Both warm-ups increased 5-s peak (observed within 10 s at the beginning of maximal cycling) and 30-s mean power output during the final 30-s maximal cycling compared to no warm-up. Moreover, the high-intensity warm-up provided a greater peak (577±169 vs. 541±175 W, P=0.01) but not mean (482±109 vs. 470±135W, P=1.00) power output than the moderate-intensity warm-up. Both VO2 during the 90-s constant workload cycling and the post-warm-up blood lactate concentration were higher following the high-intensity than moderate-intensity warm-up (all P≤0.05). We show that work-matched moderate- (~40% VO2peak) and high- (~80% VO2peak) intensity warm-ups both improve final sprint (~30 s) performance during the late stage of a 120-s supramaximal exercise bout, and that a high-intensity warm-up provides greater improvement of short-duration (<10 s) maximal sprinting performance.

Effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players.

[Purpose] The study investigated the effects of lower extremity injuries on aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function in high school soccer players. [Subjects and Methods] The study assessed U High School soccer players (n=40) in S area, South Korea, divided into 2 groups: a lower extremity injury group (n=16) comprising those with knee and ankle injuries and a control group (n=24) without injury. Aerobic exercise capacity, anaerobic power, and knee isokinetic muscular function were compared and analyzed. [Results] Regarding the aerobic exercise capacity test, significant differences were observed in maximal oxygen uptake and anaerobic threshold between both groups. For the anaerobic power test, no significant difference was observed in peak power and average power between the groups; however, a significant difference in fatigue index was noted. Regarding the knee isokinetic muscular test, no significant difference was noted in knee flexion, extension, and flexion/extension ratio between both groups. [Conclusion] Lower extremity injury was associated with reduced aerobic exercise capacity and a higher fatigue index with respect to anaerobic exercise capacity. Therefore, it seems necessary to establish post-injury training programs that improve aerobic and anaerobic exercise capacity for soccer players who experience lower extremity injury.

Caffeine ingestion improves power output decrement during 3-min all-out exercise.

PURPOSE: To investigate the effect of caffeine ingestion on the 3-min all-out test (3MT) performance and plasma electrolytes in athletes. METHODS: Fifteen collegiate male basketball players were recruited and completed two trials separated by at least 1 week in caffeine (CAF, 6 mg kg(-1)) and placebo conditions. During the first visit, participants performed an incremental cycling test to determine their 3MT resistance. After a familiarization trial, participants performed a CAF or PL trial according to a randomized crossover design. One hour after ingesting capsules, the participants performed the 3MT to estimate the end-test power (EP) and work done above EP (WEP). Blood samples for sodium (Na(+)), potassium (K(+)), pH, and lactate concentrations were drawn pretest, 1 h after ingestion, and posttest. RESULTS: Significant differences in WEP (CAF vs. PL, 13.4 ± 3.0 vs. 12.1 ± 2.7 kJ, P < 0.05) but not in EP (CAF vs. PL, 242 ± 37 vs. 244 ± 42 W, P > 0.05) were determined between the conditions. Compared with the PL condition, the CAF condition yielded significantly higher power outputs (60-150 s), a lower fatigue rate during the 3MT (CAF vs. PL, 0.024 ± 0.007 vs. 0.029 ± 0.006 s(-1), P < 0.05), a significantly higher lactate concentration after the 3MT, and significantly lower K(+) concentrations at 1 h after caffeine ingestion. There were no significant interaction effects for pH and Na(+) concentrations. CONCLUSIONS: Caffeine ingestion did not change EP but improved WEP and the rate of decline in power output during short-term, severe exercise.

Sex-Related Differences in Self-Paced All Out High-Intensity Intermittent Cycling: Mechanical and Physiological Responses.

The purpose of this study was to compare sex-related responses to a self-paced all out high-intensity intermittent exercise (HIIE). 9 women and 10 men were submitted to a maximal incremental test (to determine maximum aerobic power - MAP and VO2peak), and an HIIE cycling (60x8s:12s, effort:pause). During the protocol the mean value of V̇O2 and heart rate for the entire exercise (VO2total and HRtotal) as well as the values only in the effort or pause (V̇O2effort, VO2pause and HReffort and HRpause) relative to VO2peak were measured. Anaerobic power reserve (APR), blood lactate [La] and the respiratory exchange ratio (RER) were also measured. These variables were compared between men and women using the unpaired t test. Men used greater APR (109 ± 12%MAP vs 92 ± 6%MAP) with similar V̇O2total (74 ± 7 vs 78 ± 8% VO2peak), however, when effort and pause were analysed separately, V̇O2effort (80 ± 9 vs 80 ± 5%VO2peak) was similar between sexes, while V̇O2pause was lower in men (69 ± 6% vs 77 ± 11% VO2peak, respectively). Women presented lower power decrement (30 ± 11 vs 11 ± 3%), RER (1.04 ± 0.03 vs 1.00 ± 0.02) and [La]peak (8.6 ± 0.9 vs 5.9 ± 2.3 mmol.L(-1)). Thus, we can conclude that men self-paced HIIE at higher APR but with the same cardiovascular/aerobic solicitation as women. Key pointsMen self-paced high-intensity intermittent exercise at higher intensities than women.Men utilized greater anaerobic power reserve than women.Men and women had same cardiovascular solicitation.

Comparison of body composition, heart rate variability, aerobic and anaerobic performance between competitive cyclists and triathletes.

[Purpose] The aim of this study was to compare the body composition, heart rate variability, and aerobic and anaerobic performance between competitive cyclists and triathletes. [Subjects] Six cyclists and eight triathletes with experience in competitions voluntarily participated in this study. [Methods] The subjects' body composition was measured with an anthropometric tape and skinfold caliper. Maximal oxygen consumption and maximum heart rate were determined using the incremental treadmill test. Heart rate variability was measured by 7 min electrocardiographic recording. The Wingate test was conducted to determine anaerobic physical performance. [Results] There were significant differences in minimum power and relative minimum power between the triathletes and cyclists. Anthropometric characteristics and heart rate variability responses were similar among the triathletes and cyclists. However, triathletes had higher maximal oxygen consumption and lower resting heart rates. This study demonstrated that athletes in both sports have similar body composition and aerobic performance characteristics.

Effect of respiratory warm-up on anaerobic power.

[Purpose] The aim of the present study was to examine the effects of respiratory muscle warm-up on anaerobic power. [Subjects and Methods] Thirty male field hockey players (age, 20.5 ± 2.0 years) each participated in a control (CAN) trial and an experimental (EAN) trial. The EAN trial involved respiratory muscle warm-up, while the CAN trial did not. Anaerobic power was measured using the Wingate protocol. Paired sample t-tests were used to compare the EAN and CAN trials. [Results] There were significant increases in peak power and relative peak power, and decreases in the time to peak after the EAN trial by 8.9%, 9.6%, and 28.8% respectively. [Conclusion] Respiratory muscle warm-up may positively affect anaerobic power due to faster attainment of peak power.

Relationship between vertical jump and maximal power output of legs and arms: effects of ethnicity and sport.

The hypothesis that ethnicity and sport practice influence the relationship between maximal power in cycling (P(max)) and countermovement jump (CMJ) has been studied by relating CMJ and P(max) in two groups (volleyball players, VB, and physical education students, PES) including subjects with Caucasian (67 C) or West African (39 WA) origins. Maximal power of the arms (P(max) Arms) was also measured. A two-way analysis of variance (groups × ethnicity) showed significant effects of both factors upon CMJ, which was higher in WA and VB, P = 0.002 and P < 0.001, respectively. Within WA, CMJ was significantly higher in VB (0.732 ± 0.057 m) than in PES (0.661 ± 0.082 m), although there was no difference in P(max) (14.7 ± 1.7 vs 14.7 ± 1.9 W/kg). CMJ was significantly higher in WA (0.69 ± 0.08 vs 0.65 ± 0.09 m in C, P = 0.002) without significant interethnic difference in P(max) (14.7 ± 1.8 in WA, and 14.8 ± 1.9 W/kg in C). The CMJ-P(max) relationships were different in C and WA (P = 0.003). Therefore, CMJ predicted from P(max) would be underestimated in WA. The same difference was observed for the relationship between CMJ and P(max) Arms. These results were confirmed by the comparison with previous P(max) -CMJ relationship in the literature, collected in Caucasian and African subjects with the same protocols.

Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players.

The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key pointsThe 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed.In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity.Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can elect to assess player performance off-ice and focus on other uses of valuable ice time for their individual teams.

Sex differences in the adaptations in maximal strength and anaerobic power to upper body plyometric training.

This study aimed to compare the effects of a 6-week upper body plyometric training (UBPT) on maximal strength and anaerobic power performance of male and female subjects. Forty collegiate physically active male and female subjects participated in the study and were assigned to either UBPT group (M-UBPT, n = 10, F-UBPT, n = 10) or control group (M-CON, n = 10; F-CON, n = 10). The training groups performed 6 weeks of progressive overload UBPT three times per week using six exercises and were evaluated for upper-body anaerobic power and maximal strength, 3-kg medicine ball throw (MBT), push-up endurance, and reaction time at pre- and post-intervention. After the training intervention, the M-CON and F-CON groups did not show significant (p > 0.05) changes in the variables, while both the M-UBPT and F-UBPT groups demonstrated significant (p = 0.001) medium to very large improvements in their performance as follows: maximal strength (effect size [ES] = 0.55, 0.92), MBT (ES = 1.96, 0.89) peak power output (ES = 2.31, 1.52), mean power output (ES = 2.19, 1.11), push-up endurance (ES = 1.26, 0.70), and reaction time (ES = - 2.16, - 1.56), respectively. Nevertheless, the male group experienced more significant improvements in the MBT (p = 0.001), peak (p = 0.001) and mean power output (p = 0.01), as well as reaction time (p = 0.01) compared to the female group when utilizing UBPT. In conclusion, it is imperative to take sex into account as a crucial factor when incorporating UBPT, particularly if the objective is to enhance anaerobic power output, muscular power, and reaction time.

Optimal homeostatic stress to maximize the homogeneity of adaptations to interval interventions in soccer players.

This study examined the uniformity of adaptations in cardiorespiratory fitness and bio-motor abilities by analyzing individual responses to measures representing the mentioned qualities. Twenty-four male well-trained soccer players (Age = 26 ± 4 years; stature = 181 ± 3.8; Weight = 84 ± 6.1) were randomized to two groups performing short sprint interval training [sSIT (3 sets of 10 × 4 s all-out sprints with 20 s of recovery between efforts and 3 min of rest intervals between sets)] or a time-matched small-sided game [SSG (3 sets of 3 v 3 efforts in a 20 × 15 m area with 3 min of relief in-between)]. Before and after the 6-week training period, aerobic fitness indices, cardiac hemodynamics, and anaerobic power were assessed through a graded exercise test utilizing a gas collection system, noninvasive impedance cardiography, and a lower-body Wingate test, respectively. Also, sport-specific bio-motor abilities were determined by measuring linear speed, change of direction, and jumping ability. Comparing inter-individual variability in the adaptive changes by analyzing residuals in individual adaptations indicated that sSIT induces more uniform changes in the first and second ventilatory threshold (VT1 & VT2), stroke volume, and peak power output across team members than SSG. SSG also yielded lower proportions of responders in V˙O2⁡max, VT1, VT2, peak, and average power output compared to sSIT. Additionally, the coefficient of variation in mean group changes in measures of aerobic fitness and bio-motor abilities in response to sSIT were lower than in SSG. Short sprint interval training induces more homogenized adaptations in measures of cardiorespiratory fitness and anaerobic power than small-sided games across team members.

Construction and validation of the Wingate index model for elite athletes.

Objective: The gold standard for measuring anaerobic fitness is the power cycle ergometer test, but this method is expensive and time-consuming, and it has negative effects on pre-competition performance. This study aims to utilize the strong correlation between accessible body composition indices and less accessible anaerobic power bicycle indices to establish and verify a Wingate Index Model. Methods: A cohort of 993 male (age: 22.56 ± 3.30 years) and 450 female (age: 21.47 ± 2.70 years) athletes who participated in diverse sports were enrolled and completed the high-intensity power cycle test and body composition test, and the model formula was established based on these data. Totally, 283 participants were randomly selected to verify the formula using SPSS 22.0 and GraphPad Prism 9.4.1. Results: There was no significant difference between the value derived from the confirmed formula and the measured value of the instrument among the elite athletes (p > 0.05). The probabilities that the values obtained by the formula would fall within the 95 % confidence interval were as follows: Mpower(mean power): 94.7 %, Mpower/W(mean power/weight): 96.8 %, total work: 94.7 %, Ppower(peak power): 94.7 %, Ppower/W(peak power/weight): 95.8 %, and fatigue index: 93.6 %. Conclusion: By constructing and validating multiple regression equations for the anaerobic power cycle and body composition indices, this study showed that the probabilities of the values obtained from the equations falling within the 95 % confidence interval were 94.7 % for Mpower, 96.8 % for Mpower/W, 94.7 % for total work, 94.7 % for Ppower, 95.8 % for Ppower/W, and 93.6 % for fatigue index. Therefore, these equations may have some practical value in predicting the elite athlete population.