Search Results (499)

Jump height (JH) is widely used as an indicator of athletic performance. This study aimed to (1) evaluate the relative importance and predictive value of JH for neuromuscular performance across key physical metrics and (2) describe the neuromuscular profile of soccer players from different age groups, positions, and competitive levels. Senior (SG) and youth (YG) players were evaluated after the off season for neuromuscular power, strength, change of direction, speed, repeated sprint ability, and aerobic endurance. SG outperformed YG in most measures, especially JH, abduction strength, and Peak Power (RAST PP). Notably, YG exhibited higher maximal oxygen uptake (VO2max) and lower fatigue index (RAST FI), highlighting their robust aerobic capacity and greater ability to sustain repeated efforts. These results reinforce established developmental patterns, with aerobic endurance more pronounced in youth and anaerobic power in seniors. In seniors, JH correlated moderately with sprint and anaerobic power, while its associations in youth were weaker and linked to endurance. Positional analysis suggested overall higher JH in SG. JH emerged as a practical predictor for physical performance monitoring in seniors and a useful benchmark for athletic potential identification. Findings support targeted training and monitoring based on age-specific profiles. This study enhances applied sports science, underscoring the need for tailored approaches in player development and evaluation. Full article

Monitoring adolescent team-sport athletes may benefit from combining performance and molecular markers, but empirical evidence supporting this approach in youth team sports remains limited. Objective: Our study investigated molecular and physiological adaptations to seasonal training in elite U18 ice hockey players, focusing on aerobic capacity, salivary cortisol, serum irisin, and cell-free DNA (cfDNA) dynamics. Methods: National-level U18 players were enrolled in our study (n = 23 for cross-sectional analysis, n = 12 longitudinal) during the pre- and early-competition season. Aerobic performance was assessed via graded treadmill VO₂max testing, and the biochemical markers quantified using ELISA-based assays. Results: From pre- to early-season (paired n = 12), VO₂max increased by 10.6% (g = +1.00, p = 0.003) and irisin by 14.7% (g = +0.83, p = 0.010). cfDNA decreased by 60.8% (g = −0.54, p = 0.070; moderate effect, not statistically clear), while cortisol remained stable (+11.3%; p = 0.667). Inter-individual variability increased for VO₂max and irisin and decreased by 82% for cfDNA. Exploratory cross-sectional positional analysis indicated higher irisin levels in forwards and elevated cfDNA in defensemen, although differences did not reach statistical significance. Conclusions: These preliminary findings provide cohort-size limited longitudinal evidence of chronic irisin elevation in ice hockey players and highlight the possibility of combining VO₂max + irisin + cfDNA to assist individualized load/recovery in elite youth ice hockey. Full article

Backgrounds/Objectives: Adolescent soccer players are exposed to elevated injury risk due to rapid musculoskeletal development and high physical demands. Neuromuscular training (NMT) and speed–agility–quickness (SAQ) training are widely used to enhance performance and reduce injury risk in youth athletes. While both approaches are effective, comparative evidence regarding their modality-specific performance adaptations remains limited. Furthermore, few studies have discussed how such performance data may inform evidence-based or data-driven training selection in youth sports contexts. Methods: Thirty-six male youth soccer players with at least three years of playing experience, affiliated with Team A in Gyeonggi-do and Team B in Chungcheongbuk-do, participated in the study (NMTG, n = 21; SAQG, n = 15). Participants completed either an NMT or SAQ training program for eight weeks. To objectively assess exercise performance, pre- and post-tests were conducted measuring dynamic balance, vertical jump, zigzag run, and carioca. Results: Findings revealed a significant main effect of time for lower limb power (p < 0.05), but no significant group × time interaction, indicating that both NMTG and SAQG improved significantly over the 8-week period. Conversely, significant interaction effects were found for agility (p < 0.001), with SAQG demonstrating superior enhancements compared to NMTG. Dynamic balance showed no significant time effect or interaction. Conclusions: While NMTG and SAQG are equally effective for enhancing lower limb power, SAQG provides modality-specific advantages for agility in youth soccer players. These results emphasize time-dependent adaptations for power and the distinct benefits of SAQG for multi-directional speed. These adaptation profiles offer a data-driven framework for optimizing training selection in youth athletes. Full article

Hip and groin injuries are common in elite football, and reduced isometric adductor strength has been identified as a key risk factor. Therefore, reliable and valid field-based methods for assessing hip adduction strength are essential for effective monitoring and injury prevention. This study aimed to evaluate the intra-rater reliability and construct validity of a hand-held dynamometer (HHD) compared with the ForceFrame (FFS) during the adductor squeeze test in elite youth football players. Thirty-eight male academy athletes completed two testing sessions four weeks apart, performing maximal isometric adductor squeezes using both devices. Relative reliability was assessed using intraclass correlation coefficients (ICC), and construct validity was evaluated using paired t-tests, Bland–Altman analysis, and linear regression. The HHD demonstrated excellent intra-rater reliability (ICC = 0.90, 95% CI: 0.82–0.95) and the FFS showed good reliability (ICC = 0.85, 95% CI: 0.71–0.92). Paired t-tests revealed no significant differences between devices, and regression analysis confirmed no proportional bias, indicating strong agreement and construct validity. These findings demonstrate that the HHD provides valid and reliable measurements of isometric hip adduction strength and may serve as a practical, portable, and cost-effective alternative to fixed dynamometry for field-based strength assessment, rehabilitation monitoring, and injury-prevention screening in elite football environments. Full article

Body composition, bone mineral density, and cardiopulmonary exercise testing (CPET) are commonly used to assess aerobic fitness in athletes, but their interrelationships remain unclear. This study compared these parameters by sex and examined their associations in elite athletes. Our study included 145 youth water polo players (age: 15.7 ± 1.6 years; male: 75). Body composition was measured by DEXA, and treadmill CPET was performed using a sport-specific protocol. We analysed the correlations between the following factors by multivariate linear regression: lean body mass (LBM, LBM_index); body fat mass (BFM); percent body fat (PBF); bone mineral content (BMC); lumbar, femoral, and radial bone mineral density (LBMD, FNBMD, FTBMD, RBMD); exercise time; absolute and relative maximal oxygen uptake (VO_2absmax, VO_2relmax); maximal ventilation (VE_max). Exercise time was found to be negatively correlated with BFM, while VO_2relmax was found to be negatively correlated with BFM and PBF. VO_2absmax was found to be positively correlated with BFM, LBM, BMC, FNBMD, and RBMD. VE_max was found to be positively correlated with LBM and LBM_index. In males, VO_2absmax and VE_max were found to be positively correlated with LBMD and FTBMD. Correlations between bone density and CPET proved to be stronger in males. Our results indicate that body composition and bone density parameters influence CPET parameters, and their complex evaluation can support personalized diagnostics and athletes’ health. Full article

Objectives: Field-based testing is commonly used to evaluate key physical qualities related to soccer performance. However, limited research has examined the degree of shared variance among measures of aerobic capacity, change of direction (COD), and explosive power in youth athletes. This study investigated the relationships between the 20 m shuttle run (20MSR), T-test (TT), and vertical countermovement jump (CMJ) to determine their unique and overlapping contributions to each other’s performance in competitive youth soccer players. Methods: Twenty-five competitive male youth soccer players (13.7 ± 0.8 years) completed standardized assessments of TT, CMJ, and 20MSR during pre-season evaluations. Pearson correlations and hierarchical multiple regression analyses were used to examine associations and independent variance explained among the performance measures. Results: Large, significant correlations were observed between TT and CMJ (r = −0.65, p < 0.001), TT and 20MSR (r = −0.59, p < 0.001), and CMJ and 20MSR (r = 0.53, p = 0.007). CMJ explained 42.3% of TT variance, whereas adding 20MSR did not significantly improve model fit (ΔR² = 0.087, p = 0.062). Across models, aerobic capacity did not contribute significant unique variance beyond neuromuscular performance. Conclusions: COD and lower-body power share a common physiological foundation in youth soccer athletes, while aerobic capacity represents a distinct performance domain. When field tests are administered under applied conditions typical of youth soccer environments, TT and CMJ demonstrate substantial shared variance, whereas 20MSR remains largely independent. Therefore, the findings support the continued use of multi-modal testing batteries in practice. Full article

Our study aimed to examine and compare the effects of 12-week repeated sprint intervals with change of direction and linear sprint intervals on physical performance in young soccer players. In this randomized, parallel three-group study, we included 60 male soccer players assigned to (i) a sprint interval with change of direction group (RS–CoD; n = 20); (ii) a linear sprint interval group (RS–LiN; n = 20); and (iii) a soccer group (SOC; n = 20). Physical performance included explosive power (countermovement jump [CMJ] and squat jump [SJ]), agility (T505, 93,639, 20Y), speed (sprints over 5 m, 10 m and 20 m), anaerobic capacity (the Running-Based Anaerobic Sprint Test [RAST]) and maximal oxygen uptake (VO2max). Over the 12 weeks, the RS–CoD group displayed significantly beneficial effects in the 93639 test (effect size [ES] = 0.42), compared to the RS–LiN (ES = 0.18) and SOC (ES = 0.12) groups. The RS–CoD group also had larger improvements in their SJ (ES = 0.87; RS–LiN 0.37; SOC 0.18), CMJ (ES = 0.56; RS–LiN 0.39; SOC 0.43), 20Y test (ES = 1.05; RS–LiN 0.67; SOC 0.56) and sprints at 5 m (ES = 1.18; RS–LiN 0.50; SOC 0.21) and 20 m (ES = 1.43; RS–LiN 0.71; SOC 0.25). The RS–CoD group displayed more beneficial improvements, making the CoD interval sprints effective training stimuli. Full article

With the growing demands and expectations associated with professionalised youth sport environments, there is an increasing need for psychosocial development initiatives to support young athletes and their healthy progression. The aim of this study was to extend and investigate the application of the 5Cs framework, a prominent psychoeducational approach in sport psychology, to a youth tennis Talent Development Environment (TDE). Using a collective case study design, five athletes, their parents and two coaches (n = 12) participated in a season-long multimodal 5Cs intervention programme at a British Regional Player Development Centre (RPDC). The 30-week programme was delivered by an embedded sport psychology practitioner (SPP) and incorporated a blocked educational curriculum supported by a range of athletes, coach and parent development strategies. Post-intervention semi-structured interviews were conducted with all participants, with reflexive thematic analysis leading to three overarching themes. Findings highlighted the positive influence of the programme, with perceptions of the framework’s effectiveness associated with its specificity to tennis and individual athlete needs, the collaboration of all stakeholders across the TDE and the use of developmentally accessible and innovative strategies enabling evidence of athlete improvements. Researchers, practitioners and sport organisations are encouraged to consider these impact factors in terms of supporting the development, performance and well-being of athletes and their families in competitive youth sport contexts. Full article

Background: This study examines how contextual factors influence the match load experienced by U14 athletes. Methods: Ninety-six male players from eight Portuguese regional selection teams were monitored during three official matches each, using WIMU Pro™ inertial devices with ultra-wideband (UWB) tracking systems. Fifteen internal and external load variables were analyzed, including player load/min, high-speed running (HSR), maximum heart rate (HRmax), and high impacts/min. Mixed linear models revealed significant inter-individual variability in all variables, showing sensitivity to match context. Results: Losing teams exhibited higher player load/min. Balanced matches provoked greater cardiovascular and locomotor demands, particularly in HRmax and HSR metrics. Cluster analysis identified three match typologies based on score margin. Team level was strongly associated with final outcomes and quarter performance, reinforcing the predictive value of intra-match consistency. In contrast, match type (score margin) showed limited correlation with team quality or load distribution. Conclusions: These findings demonstrate the multifactorial nature of match load in youth basketball, supporting the implementation of individualized, context-aware training and recovery strategies while guiding long-term athlete development. Full article

Background: Reaction time and coordination are key performance components in team sports such as handball, particularly during the developmental years. Integrating visual and cognitive stimuli through smart technologies has been shown to facilitate motor skill development in young athletes. Methods: This study evaluated the effects of a BlazePod-based training protocol on reaction time, visuomotor coordination, movement quickness, and change-of-direction performance in junior male handball players aged 12–14 years. Thirty-two athletes (mean age = 13.37 ± 0.29 years) were randomly assigned to an experimental group (n = 16), in which the traditional neuromotor/coordination block of regular practice was replaced with BlazePod-based drills three times per week for eight weeks, or to a control group (n = 16), which trained the same capacities with traditional handball-specific exercises without technology. Training frequency (3 sessions/week), session duration (90 min), and the workload of the 30 min neuromotor block were matched between groups. Motor performance was assessed using four tests: Focus Reactions, Fast Feet, Clap Challenge, and the Agility T-Test. Paired- and independent-samples t-tests were applied to compare pre- and post-intervention scores. Results: The experimental group showed significant within-group improvements in Focus Reactions (p = 0.002) and AgilTT_ShuffleLeft (p = 0.014), whereas the control group showed no improvements and a small but significant worsening in Focus Reactions. Between-group comparisons at post-test revealed significant differences in favor of the experimental group for Fast Feet (p = 0.036), Clap Challenge (p = 0.008), AgilTT_Overall (p < 0.001), and AgilTT_SprintBack (p = 0.003). Conclusions: The integration of BlazePod technology into handball training produced measurable improvements in reaction speed and lateral agility among junior players. These findings suggest that technology-assisted neuromotor training represents a viable training modality that can replace a traditional neuromotor block within youth handball practice while maintaining overall training dose. Full article

Understanding how contextual variables shape differences in match demands in youth football is essential for optimising performance and player development. Objective: This study aimed to compare physical and competitive performance according to playing position, match location, match result, and opponent quality in the physical and competitive performance of U21 football players from a professional Chilean club. Methods: Twenty male U21 players (19.2 ± 1.2 years) were monitored during 11 official matches using 10 Hz GPS devices (WIMU Pro™) and post-match Rating of Perceived Exertion (RPE). Variables included total distance (TD), high-speed running (HSR > 20 km/h), metres per minute (MM), accelerations/decelerations (N°AC/N°DC > 3 m·s⁻²), player load (PL), and peak velocity (PV). Contextual variables were classified by playing position, home/away, win/loss, and opponent quality (higher vs. lower rank). Results: Significant between-group differences were found across all contextual factors (p < 0.05). Midfielders (MFs) covered greater TD and reported higher RPE, while full-backs (FBs) and wingers (WGs) reached higher HSR and PV. Away and lost matches showed greater RPE, PL, and N°AC/N°DC, alongside more goals conceded. Facing higher-ranked opponents increased RPE and HSR but reduced explosive actions. Conclusions: Physical performance in U21 football is strongly modulated by contextual factors. Coaches should adjust training load and tactical strategies according to match conditions and positional roles to optimise adaptation and competitive readiness in developmental categories. Full article

This mixed methods study explored perspectives from volunteer coaches and team parents involved in one sport-based youth development program, Junior Giants. The purpose was to (a) compare multiple perspectives on program impact and (b) investigate processes behind program impact and intentions to return. The sample (N = 11,638) included 1541 volunteer coaches, 861 team parents, and 9236 caregivers who completed an online survey assessing perceptions of players’ character development, antibullying, and league organization. Coaches and team parents also responded quantitatively and qualitatively about attending the initial training, use of practice plans, and intentions to return. Coaches reported significantly higher perceptions of participant change in character development and antibullying compared to caregivers (effect sizes were small), and team parents’ perceptions were not significantly different from coaches or caregivers. Perceptions of program outcomes did not differ by sport type (baseball v. softball), binary gender, age, or years in Junior Giants. For process variables, coaches were significantly more likely to attend the training and use the practice plans than team parents (small effects). Several themes emerged from open-ended questions, including not attending the initial team meeting due to schedule conflicts or signing up late to coach, not using practice plans due to limited time or needing modifications, and not intending to return due to child aging out or time commitment. Results suggest Junior Giants is perceived to have a positive impact and offer advice for supporting volunteers in sport-based youth development programs. Full article

Understanding the long-term effectiveness of warm-up strategies is essential for enhancing neuromuscular performance in youth soccer players. This study examined the long-term effects of integrating squat exercises into the final phase of the warm-up over nine weeks on sprint, jump, change-of-direction (COD), and aerobic performance in youth soccer players. Twenty-four male U17 players were randomly assigned to either a squat-based warm-up (experimental group [EG]) or a rondo-based warm-up (control group [CG]). The EG trained twice weekly using 3–4 sets of 4–12 repetitions at progressively increasing intensities (50–85% of 1-RM). Performance was assessed pre- and post-intervention using 10 and 30 m sprint, squat jump (SJ), countermovement (CMJ), standing long jump (SLJ), 5-jump (5JT), T-half (COD), and VAMEVAL tests. The EG showed small to large significant gains in sprint (10 m: −2.21%, Cohen’s d [d] = 1; 30 m: −1.6%, d = 0.58), jumping (SJ: +9.29%, d = 1.23; CMJ: +12.08%, d = 1.83; SLJ: +7.14%, d = 0.8; 5JT: +2.33%, d = 0.32), and COD (−1.41%, d = 0.32), while aerobic endurance showed no significant change (p > 0.05). The CG showed no significant improvements (p > 0.05). Overall, integrating brief, progressive squat exercises at the end of warm-ups twice weekly led to chronic improvements in explosive neuromuscular performance, with minimal impact on aerobic endurance. Full article

The aim of this study was to analyze the effects of different competition formats on the plyometric performance of under-13 basketball players, considering the influence of maturational age and monitored through GPS devices. Thirty-seven under-13 male basketball players (age = 12.91 ± 0.57 years) from four southeast Spanish teams participated in two different tournaments. On the first day, the tournament was played according to the official Spanish Basketball Federation (FEB) rules for under-14 players. On the second day, the competition was held with modified rules (Modified Tournament), in which the basket height was lowered to 2.90 m and the three-point line was replaced by a rectangle located 4 m from the basket. Plyometric variables, such as number of impacts (total and in zones), number of horizontal impacts (total and in zones), number of steps, number of jumps (total and in zones) and g-force of jumps during takeoff and landing, were assessed using GPS monitoring. In addition, the moderating effect of maturational age on the intervention in each of the variables under study will be evaluated. The results showed that the modified tournament (MT) showed significant differences compared to the standard format (FEB) in playing time, steps, landings 5–8 G, and takeoffs >8 G during positional attacks, as well as in horizontal impact variables during counterattacks and effective playing time. Bayesian analysis provided moderate-to-strong evidence for several of these variables, and extreme evidence for playing time and impacts during effective time. Moreover, maturational age (%PAH) consistently moderated the intervention effects, particularly in impact loads and locomotor demands. These findings can provide useful insights for coaches and practitioners in youth basketball. Adjusting competition rules and considering maturational status may optimize player development by creating contexts that enhance plyometric performance while adapting to the physical and biological characteristics of young athletes. Full article

Background and Objectives: This study compared the effects of two posterior-chain strength training strategies on eccentric hamstring strength, jump and sprint performance, and hamstring injury incidence in elite youth soccer players. Materials and Methods: Twenty-three players were randomly allocated to either a Nordic Hamstring Exercise Group (NHEG; n = 11) or a Deadlift + Leg Curl Slides Group (D + LCSG; n = 12). Both groups completed a 9-week in-season resistance training program consisting of one strength-oriented session (MD-4) and one power-oriented session (MD-2) per week, in addition to regular soccer training. Pre- and post-intervention assessments included eccentric hamstring strength (NordBord), countermovement jump (CMJ), and 10 m and 30 m linear sprint performance. Results: Eccentric hamstring strength increased significantly only in the NHEG (p ≤ 0.05), though this improvement did not transfer to enhancements in jump or sprint performance (p > 0.05). No significant changes were observed in the D + LCSG for any variable (p > 0.05), and no between-group differences were found across all performance outcomes. During the 12-week monitoring period, one hamstring injury was recorded, occurring in the NHEG. Conclusions: These findings suggest that, while the NHE elicited greater exercise-specific eccentric strength gains, neither posterior-chain strategy produced improvements in sprint or jump performance. However, given the small sample size and low number of injury events, these trends cannot be attributed with certainty to the implemented protocols, and both programs reported a low incidence of hamstring injuries per 1000 h of exposure with no statistically protective effect associated with the use of the NHE. Full article