Search Results (109)

Background: The off-season is often characterized by a significant decrease or even a complete cessation of training. If this reduction is not planned properly, it can result in detraining. Despite numerous studies examining the effects of HIIT in football players, its specific role in mitigating detraining and maintaining aerobic and anaerobic performance during the off-season in adolescent female football players remains underexplored. Therefore, this study evaluated the effects of a 4-week off-season high-intensity training (HIIT) program on aerobic performance level and sprint endurance ability in Under-15 (U-15) female football players. Methods: Fifteen U-15 female football players from a professional club completed an experimental protocol consisting of two HIIT formats: Small-Sided Games (SSGs) and Repeated Sprint Training (RST), each performed twice weekly. Before and after the intervention period, participants performed the Yo-Yo Intermittent Recovery Level 1 (YYIR1) test to gauge aerobic performance and the 30-seconds sprint test to assess sprint endurance. The internal training load was monitored via heart rate (HR) and blood lactate concentration ([La]⁺), while external training load metrics included the total distance (TD), moderate-speed distance (MSD), high-speed distance (HSD), acceleration distance (≥3 m·s⁻²; ACC), and deceleration distance (≤−3 m·s⁻²; DEC). Results: YYIR1 improved by 57% (p = 0.0001; d = 1.12; 95% CI: 121.94–224.71) and the 30-s test performance increased by 13% (p = 0.004; d = 0.91; and 95% CI: 14.46–25.53) following the intervention period. A very large correlation between time spent at 90–95% HRmax and the 30-s test (r = 0.90, p = 0.0001) and YYIR1 (r = 0.81, p = 0.0001) performance was observed. Very large and nearly perfect correlations between DHS and YYIR1 (r = 0.82, p = 0.0001) and the 30-s test performance (r = 0.94, p = 0.0001), respectively, were found. Conclusions: In U-15 female football players, a four-week off-season HIIT program improved both aerobic performance and sprint endurance ability, indicating that a HIIT regime attenuates the off-season detraining, thus supporting a better-conditioned return to play. Coaches may implement 4-week high-intensity off-season programs to enhance aerobic performance and start the pre-season with a satisfactory level of aerobic fitness and sprint endurance. Full article

This study aimed to evaluate the impact of an 8-week reverse Nordic exercise training (RNET) program on physical fitness in male youth soccer players. A total of 35 players participated in the study and were divided into two groups: the RNET group (n = 19, age 16.39 ± 0.46 years) and the active control group (CG: n = 16, age 16.53 ± 0.48 years). To assess fitness changes, participants were tested on linear sprint speed (5, 10, and 20 m sprints), change-of-direction (CiD) speed (505-CiD), vertical jump (countermovement jump [CMJ]), horizontal jump (standing long jump [SLJ]), drop jump (20 cm drop jump [DJ-20]), and repeated sprint ability (RSA). Significant group-by-time interactions were observed (effect size, [ES] = 0.70 to 1.37), with substantial improvements in the RNET group across linear sprint, CiD, and jumping performances (ES = 0.61 to 1.47), while no significant changes were noted in the CG. However, no significant group-by-time interactions were observed for RSA parameters. Individual response analysis revealed that 63–89% of RNET group exhibited improvements exceeding the smallest worthwhile change (SWC_0.2) threshold. These results suggest that the RNET program is both effective and safe for enhancing physical fitness in male youth soccer players. Full article

This study investigated the influence of aerobic capacity on lactate clearance rate and heart rate recovery during ice hockey matches. Considering the growing intensity and anaerobic demands of modern ice hockey, the ability to recover quickly between high-intensity shifts is essential for optimal performance. Thirty-eight amateur ice hockey players (age: 35 ± 5 years; VO₂max: 48.93 ± 3.88 mL·min⁻¹·kg⁻¹) from the Silesian Amateur Hockey League underwent laboratory ramp tests to determine VO₂max, followed by on-ice repeated sprint tests and heart rate monitoring during matches. The results demonstrated significant positive correlations between VO₂max and lactate clearance (ΔLa4–8min [mmol/L]= 2.55 ± 0.58 mmol·L⁻¹; rho = 0.545; p < 0.001), as well as heart rate recovery (Δ%HRmax = 25.88 ± 2.09%; rho = 0.682; p < 0.001). Players with higher VO₂max exhibited a faster reduction in heart rate during recovery periods between shifts and maintained better sprint performance (rho = –0.877; p < 0.001). These findings confirm that higher aerobic capacity enhances both metabolic and autonomic recovery processes, enabling players to sustain high-intensity efforts more effectively during the game. The study highlights the importance of developing aerobic fitness in hockey training to improve recovery efficiency and match performance. Full article

Background: Inorganic nitrate (NO₃⁻) may enhance muscle contractility and blood flow via nitric oxide production, offering potential ergogenic benefits. However, most studies have focused on males, and its effects in females during high-intensity, short-duration exercise remain unclear. Objective: This review assessed the acute effects of nitrate supplementation on muscle strength, power, and sprint performance in healthy females. Methods: A comprehensive literature search was conducted in PubMed, Web of Science, Scopus, SPORTDiscus, and Cochrane CENTRAL, from inception to July 2025. Randomized controlled trials (RCTs) that examined the effects of oral inorganic nitrate (e.g., beetroot juice or nitrate salts) in healthy females were included. Eligible studies involved (i) healthy women aged 18–30, (ii) nitrate supplementation vs. placebo, and (iii) outcome measures of muscle strength (e.g., MVC), power (e.g., countermovement jump height, peak power), or sprint performance (e.g., sprint time or repeated sprint ability). Studies were excluded if they did not report sex-specific results or lacked relevant physical performance outcomes. Random-effects meta-analyses were conducted for each outcome. Results: Nitrate supplementation had small, non-significant effects on muscle strength (SMD = 0.10, 95% CI: −0.10 to 0.30, p > 0.05) and sprint performance (SMD = 0.14, 95% CI: −0.13 to 0.41, p > 0.05). A statistically significant, small-to-moderate improvement was observed in power (SMD = 0.38, 95% CI: 0.06 to 0.69, p < 0.05). Sensitivity analyses confirmed robustness of the power result. The certainty of evidence ranged from low to moderate based on the GRADE assessment. Conclusions: Inorganic nitrate supplementation may modestly enhance power in healthy females but does not appear to significantly improve muscle strength or sprint performance. These findings highlight the importance of sex-specific research in sports nutrition to guide targeted supplementation strategies for female athletes. Full article

Objectives: Sprinting and jumping abilities are key determinants of basketball performance. This study aims to analyze changes in sprinting and jumping performance among professional basketball players during the preseason and to determine whether these adaptations are influenced by specific playing positions (Guards vs. Bigs). Methods: A total of 106 professional basketball players from European leagues were evaluated twice over a 6-week preseason. Neuromuscular assessments included linear sprints (5, 10, and 20 m), a change of direction test, curved sprints, and multiple jump tests: Squat Jump (SJ), Countermovement Jump (CMJ), Single-Leg CMJ (SL-CMJ) and Arm-Swing CMJ (CMJA), Single Leg Hop for Distance (SHDJ), Lateral Bound Jump (LBJ), and Single-Leg Repeated Jumps (SLRJ). The training program integrated 6–8 weekly basketball-specific technical–tactical sessions with two to three strength and conditioning sessions targeting maximal strength, power, and hypertrophy. Results: Players significantly improved linear and curved sprint performance, and jumping ability, particularly CMJ, CMJA, and right-leg SHDJ. Minimal changes were observed in SJ, LBJ, and SLRJ. Positional differences were small, with Guards showing greater gains in CMJA than Bigs (6.85% vs. 1.87%). Conclusions: A 6-week preseason training program may be associated with improvements in sprinting (linear 5, 10, 20 m, and curved sprint) and vertical jump performance (CMJ, CMJA, SHDJ) in professional basketball players, with limited influence of playing position. Guards appear to benefit more from arm-swing vertical jump development. 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

This study investigated the relationship between reactive strength and sprint acceleration performance in elite under-21 hurling athletes. Reactive strength was assessed using the 10/5 Repeated Jump Test (RJT), while sprint performance was measured over 30 m with split times at 5, 10, 20, and 30 m. Twenty-four male players participated in the study. The results revealed large, significant correlations between reactive strength index (RSI) and sprint times in the 5–10 m, 10–20 m, and 20–30 m splits but not in the initial 0–5 m phase. Further analysis showed that athletes with higher RSI scores exhibited significantly shorter ground contact times (CT_SPRINT) and superior sprint performance in the 20–30 m segment without compromising step length. These findings suggest that reactive strength plays a crucial role in mid-to-late-phase acceleration, likely due to the ability to produce force rapidly during short ground contact durations. The study also identified a significant, negative correlation between RSI and CT_SPRINT, indicating a possible mechanical link. These results support the inclusion of reactive strength development in training programs aiming to enhance sprint performance, especially in field sports requiring repeated high-intensity sprints. 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: Previous work has found that combining plyometric and resistance training in a single session can be effective in improving maximum strength (muscle contraction ability), vertical jumping, and sprint acceleration performance in young soccer players. However, the literature is scarce in relation to young rugby union players. Thus, the purposes of the present study were to examine the effects of a 6-week combined training (CT) programme that combined plyometric and resistance training in the same session on physical performance measures in adolescent male rugby union players and whether a 4-week period of plyometric training exclusion (Detraining) affects training adaptations. Methods: The participants (n = 15) completed a 6-week CT intervention and 4 weeks of plyometric detraining during the schoolboy rugby union in-season. A performance testing battery was conducted pre-intervention, post-intervention, and 4 weeks post-intervention. Results: A repeated measures ANOVA showed a significant effect for time on CMJ variables (mean power, mean force, and modified reactive strength index [RSI]), 3RM back squat strength, and 505 test time (p < 0.05). Pairwise comparisons revealed that CMJ variables (mean force, mean power, and peak power), 3RM back squat strength, and 505 test performance significantly increased from pre-intervention to post-intervention (p < 0.05). The 4-week plyometric detraining period significantly augmented CMJ variables (mean force, mean power, and modified RSI) and performance measures (standing broad jump [SBJ], 20 m sprint time, 505 test, and 3RM strength). Conclusions: The findings indicate that a 6-week CT programme can augment measures of lower-body power, maximal strength, and change of direction performance in adolescent male rugby union players, and a 4-week resistance training-only period (plyometric detraining) does not negatively affect performance adaptations. Full article

Listening to self-selected motivational music (SSMM) during warm-ups and caffeine (CAF) intake prior to exercise can independently enhance athletic performance among female athletes. Likewise, the potential synergistic effects of these interventions have not yet been thoroughly examined. Objective: The purpose of the study was to assess the independent and combined effects of SSMM during warm-up and pre-exercise CAF intake on maximal short-duration performance in female athletes. Methods: Seventeen female handball players (aged 16.7 ± 0.4 years) participated in a randomized, double-blind, crossover study. Each athlete completed four conditions: (i) placebo (PLA) with no interventions, (ii) music and placebo (MUS), (iii) caffeine intake only (CAF), and (iv) a combination of music and caffeine (MUS + CAF). Performance assessments included the countermovement jump (CMJ), modified agility t-test (MAT), repeated-sprint ability (RSA) test (mean and peak sprint performance), and rating of perceived exertion (RPE). Results: The MUS (p > 0.05; p < 0.01; p < 0.01; p < 0.001, respectively), CAF (all p < 0.001), and MUS + CAF (all p < 0.01) conditions significantly outperformed the PLA condition in CMJ, MAT, RSA mean, and RSA peak measures. No significant differences were observed between the CAF and MUS + CAF conditions; however, the best performances were recorded during MUS + CAF. RPE scores remained consistent across conditions. Conclusions: Warm-up routines incorporating either SSMM or a moderate dose of CAF (6 mg·kg⁻¹) enhance anaerobic performance in female athletes. While both interventions are effective independently, CAF intake elicits a stronger effect. Although no significant difference was demonstrated for this combination, the concurrent use of SSMM and CAF appears to produce a potential effect, emerging as the most effective strategy for optimizing anaerobic performance. Full article

The aim of the study was to examine the safety and effects of relatively high caffeine doses on physical performance and sport-specific skills of young elite soccer players. Fifty-four soccer players from an elite Russian soccer academy participated in the blinded randomised placebo-controlled study with a double-blinded and balanced design. Participants were divided into four groups: group 1 CAF/CAF; group 2 CAF/PLA group 3 PLA/PLA and group 4 PLA/CAF. All participants were administered 400 mg of caffeine or the placebo. The data demonstrated that a single 400 mg caffeine administration 60 min before exercise had a positive effect on repeated sprint ability (RSA) test parameters such as fatigue index (for both groups p < 0.001) and percentage decrement score (for both groups p < 0.001). In group 4, statistically significant improvements were also found when performing the fourth and sixth sprint during the RSA test (p = 0.039 and p = 0.005, respectively). Group 1 also showed a statistically significant improvement in dribbling speed performance (p = 0.048). It was demonstrated that the number of adverse events in all four groups was not different (p = 0.56). A single administration of 400 mg of caffeine 60 min prior to maximal intensity physical activity can be considered reasonable and safe for young elite soccer players. Full article

Evidence supports the role of palmar cooling to improve exercise performance, especially with endurance and resistance activities. The aim of this randomized placebo-controlled trial was to explore the effects of palmar cooling on repeated sprinting performance and recovery. Fifteen graduate students were randomly assigned to either a palmar cooling intervention or placebo group (males: n = 8, females: n = 7; Avg. age: 24.06 yrs.) After a ten-minute warm-up, participants completed ten sixty-meter sprints that included two 180-degree changes of direction. Three bouts of two-minute intervention or placebo occurred during the study. Data for sprint times, heart rate, and RPE were collected throughout testing. A muscle soreness rating was collected via survey 48 h post intervention. Statistically and practically significant differences were found between groups for average sprint times, heart rate, and delayed onset muscle soreness. The intervention group utilizing palmar cooling demonstrated less degradation in sprint times, lower heart rate upon completion, and a lower soreness rate 48 h after testing. More research is needed with a larger sample size to determine if practical and statistically significant differences will be maintained and would allow for a more robust multivariant analysis, resulting in the findings being more generalizable to a larger population. Full article

Purpose: To investigate the influence of upper body (UB) strength qualities and UB strength training on the performance of high-intensity running and jumping actions and to identify gaps and recommendations for future research. Methods: A systematic search using the PRISMA Scoping Review protocol was conducted in February 2024 using PubMed, Scopus, and ICTRP. Studies eligible for inclusion were those that reported associations between UB or trunk maximal strength qualities (e.g., absolute strength, forces, power) and high-intensity running or jumping actions or investigated the influence of an isolated UB strength training intervention on high-intensity running or jumping performances. Results: Of the 4730 articles, 7 studies met the inclusion criteria, reporting correlations for 16 high-intensity running or jumping tests. No intervention studies were identified. Preliminary findings of the limited number of studies highlight that greater UB maximal strength-generating capacity may positively influence repeated sprint ability. While a significant moderate correlation between greater absolute UB strength and faster “flying” sprint was also reported, mixed results were found for sprint acceleration. There is also evidence that change-of-direction performance may greatly benefit from high maximal isometric strength of all trunk muscles and that strong trunk extensors may enhance drop jumps. Conclusions: This review identifies the potential of UB strength to contribute to high-intensity running and jumping actions. Future research is warranted to investigate this link via various UB strength tests and UB strength training protocols aimed at maximising neuromuscular adaptations. Full article

(1) Background: Enhancing repeated sprint ability (RSA) is critical to soccer performance. Post-activation performance enhancement (PAPE) protocols, particularly those utilizing heavy resistance preloading, have shown promise in improving RSA. Yet, the optimal preloading intensity for amateur players is still unknown. This study investigated the effects of two PAPE protocols using different preloading intensities (85% and 90% of 1 RM back squat) on RSA. (2) Methods: A double-blind, randomized, two-period crossover design was used, and 18 amateur male players were included in this study. RSA was assessed using a 6 × 35 m sprint protocol with 10 s rest intervals (RAST). (3) Results: While the main effect of time significantly (p = 0.01, η² = 0.71) influenced performance decline across all groups, there was no significant (p = 0.65, η² = 0.01) interaction between time and condition. Individual responses to PAPE varied, highlighting the importance of individual differences. Interestingly, the BS85% group exhibited a less pronounced decline in performance compared to the control group, while the BS90% group only showed significant differences in three sprint levels. (4) Conclusions: Our findings suggest that a lower preload of 85% of 1 RM may be as adequate as a higher preload of 90% of 1 RM in enhancing RSA in amateur soccer players. These results may indicate a potential fatigue-delaying effect of PAPE protocols and emphasize the importance of individualized approaches for optimizing PAPE strategies. Full article

Elite athletes are an under-represented population in scientific studies, and there are no works analysing the influence of hypoxia in elite triathletes. The aim of this study was to analyse the influence of different methods of normobaric hypoxia on repeated sprint ability (RSA) performance. This study was a case study with an elite triathlete who has won nine triathlon world championships. The study used a combination of different methods of normobaric hypoxia. The three methods combined were as follows: live high-train low interspersed; intermittent hypoxic training; and intermittent hypoxic exposure. This study analysed the influence of these methods on RSA performance in variables such as power output, saturation of muscular oxygen, heart rate and ventilatory variables (VO₂ and VCO₂). The triathlete was measured before the training protocol (PRE), just after (POST-D3) and 21 days after the end of the protocol (POST-D21). This type of protocol has shown that it can lead to an improvement in RSA performance in the number of sprints (PRE vs. POST-D3 vs. POST-D21: 19 vs. 24 vs. 28), power output (PRE 615 W vs. POST-D3 685 W vs. POST-D21 683W) and efficiency of the triathlete. This work may be useful in improving power output and repeated sprint ability for elite triathletes. Full article