Search Results (53)

Background: Change of direction (COD) and sprint abilities are essential in soccer, while reactive agility involves decision-making and perceptual/cognitive skills. This study aimed to examine the relationships between sprint speed, COD, and reactive agility in U12 soccer players. Methods: Thirty-three male players (age 10.40 ± 0.32 years) completed sprint tests (5 m, 10 m, 15 m), the Modified Agility T-Test (MAT), and the Y-Shaped Reactive Agility (Y-RSA) test, across two sessions. Results: The sprint, COD, and reactive agility tests showed high reliability. The Y-RSA test demonstrated strong reliability in regard to the initial sprint, COD-phase time, and total time. Significant correlations were found between sprint, COD, and reactive agility metrics. The sprint times were positively associated with the MAT and reactive agility times (e.g., sprint 15 m vs. total Y-RSA time: r = 0.740, p < 0.01). The smallest worthwhile changes (SWCs) indicated that these tests effectively detect performance improvements. Conclusions: This study demonstrated significant correlations between sprint speed, change of direction, and reactive agility in U12 soccer players, with the 15 m sprint showing the strongest association with reactive agility. These findings support the combined use of physical and perceptual/cognitive assessments to better inform soccer-specific training and evaluate the performance of youth players. 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

(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

This study aimed to compare two female field hockey teams of different competitive levels by analyzing kinematic variables in repeated sprint ability (RSA) tests and the force-velocity profile (FVP). Twenty-five female hockey players representing the elite and subelite levels from the same club volunteered to participate. The RSA protocol included six 30 m maximal sprints with a 30 s recovery. Kinematic variables, such as sprint time, step frequency, and step length, were analyzed for each sprint. Additionally, players performed counter-movement jumps (CMJs) and CMJs with 50% body weight (CMJ50s) to calculate the FV50 using the Bosco Index. The elite players showed better (≈2%; p < 0.05) fatigue indexes in sprint time (0–30 m and 0–10 m sections), step length (0–10 m, 10–20 m, and 20–30 m sections), and step frequency (20–30 m section) during the RSA test, as well as greater values (>10%; p < 0.05) in the CMJ50 and FV50 tests. In addition, these RSA (sprint time, step frequency, and step length) and jumping (CMJ, CMJ50, and FV50) variables showed a moderate, significant, or very significant relationship with each other. Therefore, it seems that both strength and speed capacities can be used either in conjunction or as a complementary approach to enhance the overall RSA performance. Full article

The testosterone to cortisol ratio (T:C ratio) is a measure of whether elite athletes are recovering from their training. This study described this hormone balance stress in elite women’s basketball. (1) Objectives: to analyse the fluctuation of T:C ratio over a 16-week period and explore itis relation to their athletic performance. The participants characteristics were: (height: 177.6 ± 6.4 cm; body mass: 77.808 ± 12.396 kg age: 26.0 ± 5.9 years; and a playing experience of 14.7 ± 2.9 years with 5.0 ± 1.2 years at the elite level. The T:C ratio at Time 1 is: 4.0 ± 2.4 (n = 12); and at Time 2 is: 5.1 ± 4.3 (n = 12). (2) Methods: during 16 weeks of competition, participants underwent analysis of blood samples to assess various biochemical parameters including hormone levels. In addition, their athletic performance was assessed with the following tests: jumping (SJ, CMJ, ABK, DJ); throwing test with a medicine ball (3 kg); Illinois COD agility test; sprint repeatability with change of direction; 20-m speed test without change of direction; and Yo-yo intermittent endurance test IET (II). (3) Results: The main alterations observed were an increase in T levels (1.687%) and a decrease in C levels (−7.634%) between moments, with an improvement (26.366%) in the T:C ratio. Improvements were also observed in some of the tests developed, such as jumping (SJ: 11.5%, p = 0.029; CMJ: 10.5%, p = 0.03; DJ: 13.0%, p = 0.01), upper body strength (MBT: 5.4%, p = 0.03), translation ability (20 m: −1.7%), repeated sprint ability (RSA: −2.2%), as well as intermittent endurance test (Yy (IET): 63.5%, p = 0.01), with significant changes in some of the performance tests. (4) Conclusions: T:C ratio may differ in a manner unrelated to training volume, showing some variation. These results may be attributed to the accumulation of psychophysiological stress during the season. Full article

There is evidence that both intra-serial variable resistance (I-sVR), as pre-activation within the post-activation performance enhancement cycle (PAPE), and creatine and caffeine supplementation increase athletic performance in isolation. However, the effect of the three conditioning factors on 30 m repeated sprint ability (RSA) performance in young soccer players is unknown. This study determined the summative and isolation effect of ergogenic aids and pre-activation in half-back squats (HBSs) with I-sVR on performance in an RSA test in young soccer players. Twenty-eight young soccer players were randomly assigned to either EG₁ (n = 7, creatine + caffeine + I-sVR), EG₂ (n = 7, creatine + placebo₂ + I-sVR), EG₃ (n = 7, placebo₁ + caffeine + I-sVR), or EG₄ (n = 7, placebo₁ + placebo₂ + I-sVR), using a factorial, four-group-matched, double-blind, placebo-controlled design. Creatine supplementation included 0.3 g/kg/day for 14 days, caffeine supplementation included 0.3 mg/kg per day, and pre-activation in HBS with I-sVR (1 × 5 at 30% 1RM [1.0–1.1 m/s] + 1 × 4 at 60% 1RM [0.6–0.7 m/s]). The RSA test and HBS outcomes were evaluated. Three-way ANOVA showed non-significant differences for the RSA test and HBS outcomes (p > 0.05). At the end of this study, it was found that the three ergogenic aids, together, do not generate a summative effect on the physical performance of young soccer players. However, it is important to analyze individual responses to these specific protocols. Full article

Background: Repeated sprint ability (RSA) is defined as the ability to recover and maintain maximal effort during repeated sprints, recognised as a crucial performance component in team sports. The exercise mode used to test RSA may influence performance and the contributions of different energy systems. The primary aim of this study is to address the critical gap between traditional cycling-based anaerobic tests, such as the Wingate test, and the practical, sport-specific demands of running in field-based team sports. Methods: This study involved 32 professional soccer players (age: 21.2 ± 1.3 years; height: 177.8 ± 4.3 cm; and mass: 71.3 ± 6.4 kg). They performed cycling- and running-based repeated sprint tests, with similar total sprint numbers, durations, and recovery times, on different days. Contributions from adenosine triphosphate-phosphocreatine (ATP-PCr), glycolytic, and oxidative systems were estimated through body weight, oxygen uptake (VO₂), blood lactate (BLa), and the fast component of excess post-exercise oxygen consumption (EPOC). The VO₂ levels and heart rate (HR) were monitored during the rest (10 min), exercise, and recovery (15 min) phases in a breath-by-breath mode using a portable gas exchange system. BLa was measured before (at rest) and 1, 3, 5, 7, and 10 min after the running and cycling tests using a handheld portable analyser. A mono-exponential model estimated the ATP-PCr system contribution, calculated using the fast component of EPOC following the final sprint and the sum of the VO₂-time integral during rest intervals. Results: The cycling tests demonstrated significantly higher values for the peak power (PP), mean power (MP), and rate of perceived exertion (RPE) (p < 0.05), while the heart rate peak and blood lactate responses were similar across all modalities. The fatigue index was notably higher in the running tests (p < 0.05). Furthermore, the running tests showed greater contributions in both the percentage and absolute terms from the adenosine triphosphate-phosphocreatine (ATP-PCr) system (p < 0.01), total energy demand (p < 0.05), and total energy expenditure (TEE) (p < 0.01). Notably, the running tests resulted in an increased phosphocreatine breakdown (p < 0.05) and rapid phosphocreatine replenishment (p < 0.01). A simple linear regression analysis highlighted a significant determination coefficient between these performance variables and the contributions of the energy systems, affirming the robustness of the results. The correlation heatmaps further illustrated these relationships, with higher correlations for the PP and MP across modalities (0.41), emphasising the moderate association between cycling and running tests in these metrics. Conclusions: This study elucidated the similarities and differences in energy system contributions and performance outcomes between a cycling and a running repeated sprint protocol, with a comparable total sprint time and work–rest ratio. The findings reveal that a running repeated sprint test elicits a higher energy demand and a higher contribution from the PCr energy system compared to cycling. Performance variables were not associated between running and cycling tests, suggesting those tests cannot be used interchangeably. Full article

While previous studies have explored a range of factors governing the optimal use of caffeine (CAF) in athletes, limited research has explored how time of day (TOD) affects the ergogenic effects of various CAF dosages on physical performance. This study aimed to increase knowledge about how different recommended CAF doses (3 mg/kg vs. 6 mg/kg) ingested at different TODs affected maximal high-intensity physical performance and the perception of potential side effects in female athletes. In this double-blind, randomized, and counterbalanced study, 15 low CAF consumer athletes (aged 18.3 ± 0.5 y) underwent six trials, including three testing conditions assessed across two TODs: one in the morning (08:00 a.m.) and one in the evening (06:00 p.m.). During each condition, the participants ingested either a placebo, 3 mg/kg CAF (CAF (3 mg)), or 6 mg/kg CAF (CAF (6 mg)) capsules 60 min before each test with an in-between washout period of at least 72 h. In each trial, the participants performed a countermovement jumps test (CMJ), a modified agility t test (MATT), a repeated sprint ability (RSA), a rating of perceived exertion (RPE), and finally, a CAF side effects questionnaire. Our findings indicate the absence of an ergogenic effect on CMJ, MAT, and RSA performance in the evening after administering CAF (3 mg) or CAF (6 mg) compared to a placebo. Likewise, when CAF was ingested in the morning, there was an improvement in these performances with both CAF (3 mg) and CAF (6 mg), with greater improvement observed after CAF (6 mg). Additionally, neither the CAF dosage nor the TOD had a significant effect on the RPE. The occurrence of side effects increased significantly after the evening ingestion of CAF, particularly with a moderate dose of CAF (6 mg). Our findings indicate that the effectiveness of CAF depends on the TOD and CAF dosage. When ingested in the morning, a moderate dose of CAF (6 mg), rather than CAF (3 mg), is more effective in improving short-term physical performance without affecting CAF side effects in female athletes. Nevertheless, when ingested in the evening, neither dose was sufficient to enhance short-term physical performance, and both dosages increased the incidence of CAF side effects, particularly at a moderate dose. Full article

This prospective crossover study aimed to investigate the effect of binaural beat therapy music on soccer player performance. Between July 2023 and December 2023, 45 athletes (31 females/14 males, mean age = 20.47 ± 0.99) wore Bluetooth earphones through which one of the following was given during initial 20 min warm-up exercises before undergoing repeated sprint ability tests: no music/fast-tempo music/fast-tempo music with background binaural beat therapy music. Heart rate change after warm-up exercises/repeated sprint ability (RSA) tests and the time to finish RSA tests were recorded. Despite no significant difference in heart rate increase after warm-up between the two genders regardless of intervention, larger increases after RSA tests were found in males following any of the three interventions (all p < 0.01) with the most notable difference observed after fast-tempo music (p < 0.0001). A significant effect size (r = 0.2) correlated with fast-tempo music during warm-up in either gender. Binaural beat therapy music during warm-up reached a significant effect size only when all participants were considered, suggesting limited benefits. Full article

Caffeine (CAF) is among the most extensively researched dietary supplements worldwide. However, little is known about the relationship between dosage and performance enhancement, particularly in female athletes. This study aimed to explore the effects of three different CAF dosages (3 mg·kg⁻¹, 6 mg·kg⁻¹, and 9 mg·kg⁻¹) on high-intensity exercise and the prevalence of undesirable side effects related to these doses among female team-sports athletes. All participants (n = 16; age: 16.9 ± 0.6 y; height: 1.64 ± 0.1 m; BMI: 21.6 ± 1.5 kg·m⁻²) were mild CAF consumers. This study had a randomized, crossover, double-blind design in which each athlete performed four experimental sessions after ingesting either a placebo (PLAC), 3 mg·kg⁻¹ CAF (CAF-3), 6 mg·kg⁻¹ CAF (CAF-6), or 9 mg·kg⁻¹ of CAF (CAF-9), with an in-between washout period of at least 72 h. In each experimental session, 60 min after ingesting the capsules, participants underwent a countermovement jumps test (CMJ), modified agility t-test (MATT), repeated sprint ability (RSA) test, and a rating of perceived exertion (RPE) and completed the CAF side effects questionnaire. Our findings revealed that in comparison to the PLAC condition, the MATT, RSA_mean, and RSA_best performances were significantly greater only under the CAF-6 and CAF-9 conditions. Although the RPE scores remained unchanged, CMJ performance improved under all CAF conditions. All the performance outcomes were better for the CAF-6 and CAF-9 conditions than for the CAF-3 condition. Notably, no significant difference between the CAF-6 and CAF-9 conditions was observed for any of these parameters despite the highest incidence of side effects being noted for the CAF-9 condition. In summary, our findings highlight the recommendation for a moderate CAF dosage of 6 mg·kg⁻¹ rather than 3 or 9 mg·kg⁻¹ to enhance various aspects of short-term maximal performance in mild-CAF-consumer female team-sports athletes while mitigating the occurrence of adverse CAF side effects. Full article

This study aimed to compare the effects of an 8-week short-term training program, comprising repeated sprints or running-based high-intensity intermittent training (HIIT), on the aerobic fitness and repeated sprint ability (RSA) performance of sub-elite basketball referees. Twenty male referees participated in supervised training sessions twice a week. They were randomly assigned to either the RSA-based group (RSAG) or the running-based HIIT group (HIITG). The RSAG conducted 3–4 sets of 8 × 20-m all-out sprints, while the HIITG performed 2–3 sets of 6 × 20-s runs at 90% of their maximal velocity achieved in the 30–15 intermittent fitness test (30–15_IFT). Referees underwent a graded exercise test on a treadmill, the 30–15_IFT, and an RSA test before and after the training program. Both groups showed significant improvement (~3%) in the fastest (22.6 ± 1.4 vs. 23.4 ± 1.7 and 22.0 ±1.9 vs. 22.4 ± 1.7 km·h⁻¹ in RSAG and HIITG, respectively) and mean (21.5 ± 1.2 vs. 22.4 ± 1.4 and 21.3 ± 1.8 vs. 21.7 ± 1.6 km·h⁻¹ in RSAG and HIITG, respectively) sprint velocity of the RSA test (p < 0.05). Moreover, positive changes (p < 0.05) were observed in the 30–15_IFT maximal velocity (18.6 ± 1.1 vs. 19.3 ± 1.0 and 19.4 ± 0.9 vs. 20.5 ± 0.9 km·h⁻¹ in RSAG and HIITG, respectively). In conclusion, an 8-week training intervention using either RSA or running-based HIIT led to similar improvements in referees’ RSA performance and specific aerobic fitness measures. These findings could assist in devising tailored training programs for basketball referees. Full article

Aiming to identify the ideal suhoor timing for maintaining optimal physical performance and health indicators during Ramadan intermittent fasting, the present study compares the effects of early vs. late Suhoor on short-term high-intensity physical exercise while controlling the body mass index (BMI) oral temperature (OT), dietary intake, and sleep patterns. In a randomized design, 19 female pre-university handball players (age: 16.8 ± 0.4 y; height: 1.70 ± 0.9 m; and body mass: 61.5 ± 6.9 kg) underwent two test sessions (at 08:00 a.m. and 05:00 p.m.) at four different conditions: ten days prior to Ramadan (R − 10), the final ten days of Ramadan (R) including both Early Suhoor R(ES) and Late Suhoor R(LS) conditions, and the ten days immediately following Ramadan (R + 10). A recovery period of at least 48 h has been set between successive test sessions at each period. Outcome measures included the Countermovement Jumps Test (CMJ), Modified Agility t-Test (MATT), Repeated Sprint Ability (RSA), and Rating of Perceived Exertion (RPE). The Pittsburgh Sleep Quality Index (PSQI), OT, BMI, and daily diary intake were assessed across the three periods. The total scores of PSQI decreased significantly during R and R + 10 compared to R − 10. When performed in the afternoon, CMJ, MATT, and RSA performance decreased significantly at R(ES) and R(LS) conditions compared to R − 10. However, these performances decreased only after R(ES) when performed in the morning. Furthermore, performances were lower during R(ES) compared to R(LS) in the afternoon for all tests and the morning for MATT and RSA tests. These findings support prior research showing a deterioration of physical performance during Ramadan fasting and indicate a more pronounced impact following early Suhoor condition. Therefore, consuming a late suhoor, closer to pre-dawn time, could be suggested as an effective strategy to minimize physical performance decline during short-term high-intensity exercise. Full article

Understanding the physical fitness elements that influence high-intensity running ability during rugby matches is crucial for optimizing player performance and developing effective training strategies. In this study, we aimed to investigate the relationships between various physical fitness components and high-intensity running ability in rugby. For this purpose, 60 Japanese university rugby players were randomized into four groups and two matches were played. The participants were monitored in two matches, and their running abilities were assessed using GPS sensors. The running time was divided into three running velocity categories: distance run at ≤5.4 km/h (low-intensity running); distance run at 5.5~17.9 km/h (medium-intensity running), and distance run at ≥18.0 km/h ≤(high-intensity running) and backs and forwards were evaluated separately. To determine which physical fitness test is more predictive of performance, we decided to correlate several physical test performances with the running time intensities during the matches. Independently of the position, the high-intensity running time correlated with the repeated sprint ability (RSA) and the 40 m sprint speed. The results suggest that RSA measured in the field is the most important high-intensity running ability predictor during a match for both positions. Full article