Biology of Sport最新文献

This study aimed to evaluate how varying levels of information granularity affect the output variability and multidimensional quality - including Personality, Effectiveness, Safety, and Feasibility - of ChatGPT-generated training programs. A crossover design was used to compare simple and detailed input prompts, with each prompt input into GPT-4 (accessed via ChatGPT) four times to generate eight training programs. The training programs were anonymized by the research team and subsequently evaluated in a blinded manner by 11 experts (mean age = 35.4 years, average of 18.1 years of practical experience in the field of sport and exercise science). Output variability was assessed using the coefficient of variation (CV%), and quality ratings were based on a custom 15-item scale covering Personality, Effectiveness, Safety, and Feasibility. Differences in expert ratings across training programs were examined using repeated-measures ANOVA, with Friedman tests applied as sensitivity analyses to test the robustness of the results. Training programs generated from detailed input prompts consistently received higher expert ratings across all dimensions. CV% was generally lower under the detailed input prompts, indicating more stable outputs. Significant main effects of information granularity were found in Personality, Safety, Feasibility, and overall scores (all p < 0.05), though not in Effectiveness. Notably, repeated inputs of the same information granularity still yielded structurally and qualitatively different outputs, highlighting residual variability even under controlled conditions. Information granularity plays a crucial role in shaping the quality and stability of AI-generated training programs. Providing detailed, structured input enhances personalization, reduces output fluctuation, and improves alignment with exercise science principles.

The current literature suggests that football (soccer) players' age and maturity status affect the likelihood of sustaining certain injuries; however, few studies have used indicators of sexual maturity. By retrospectively analysing prospectively collected data, we therefore aimed to describe injury patterns among young football players in a Spanish academy over three seasons and investigate associations with sexual maturity status. Participants included 354 male youth players aged 7 to 18, categorised into five age groups. Maturity assessments were conducted annually, utilising pubertal stages for genitalia and pubic hair, alongside testicular volume measurements. Time-loss injuries were recorded by medical staff and associations with pubertal stages were examined using Generalized Estimating Equations (GEE). Results indicated an overall incidence of 2.2 injuries per 1000 hours. Higher injury rates were observed for more advanced maturational stages (p < 0.05). Common injury types included muscle injuries (23%), joint sprains (20%), and growth-related injuries (16%), with specific injuries varying by maturity stage. For instance, growth-related injuries peaked during mid-puberty, while muscle and joint injuries were more frequent in advanced maturity stages (p < 0.05). Our findings suggest that sexual maturity status was significantly associated with injury occurrence in youth football. This emphasises the importance of understanding the interplay between biological maturity and injury occurrence. In addition to considering players' age or playing level, coaches and clinicians may consider tailoring training and injury prevention strategies according to players' maturity levels to better mitigate injury risks.

The multifactorial and complex nature of athletic injuries complicates the establishment of clear cause-and-effect relationships, making it challenging to pinpoint precise injury aetiology in the operational field. Research has explored the connection between injuries and training load (TL), identifying an association between high external loads (EL)-such as high-speed running (HSR) and sprinting-and non-contact hamstring injuries. Despite this, injury prevention remains largely ineffective, possibly reflecting a gap between scientific knowledge and practical application, as well as cognitive biases in translating research into real-world scenarios. This paper aims to: 1) summarize key findings on non-contact injuries in soccer, focusing on risk factors and the TL-injury relationship; 2) describe major conceptual frameworks and highlight cognitive biases when attributing injuries exclusively to TL; 3) propose new conceptual frameworks for non-contact injuries, with a primary focus on hamstring injuries. Using a qualitative approach, we present a multilevel causation framework that underscores the significant-but not exclusive-role of sprinting and TL in injury occurrence. We introduce two key concepts: acute mechanical load tissue exposure (AMLTE), referring to the peak acute mechanical stress a muscle can tolerate, and chronic muscle tolerance to load (CMTTL), representing the capacity to endure load over time. We aimed to support a data-informed approach to injury risk management and TL monitoring in daily practice. While we stress that TL and sprinting are not the sole causes of injury, we assert their relevance within a multifactorial model. This framework may assist professionals in developing more effective training strategies and injury prevention practices.

Biological maturation is one of the determinants influencing physical performance, yet its impact on asymmetry in soccer-specific tasks remains poorly understood. This cross-sectional study investigated the effects of biological maturation on inter-limb asymmetry in lower limb muscle volume (LLMV), linear and changeof-direction (COD) sprints (with and without the ball), jump performance, and dynamic balance. The agreement between asymmetry indices in dribbling tasks was assessed using Kappa coefficients to determine the consistency of asymmetry direction across tasks. Eighty-three young male soccer players (Pre-PHV: n = 42, Circa-PHV: n = 30, Post-PHV: n = 11) performed (1) 10-m sprint and 90° COD tests with- (S10_drib and COD_drib, respectively) and without the ball (S10_run and COD_run, respectively), (2) bilateral and unilateral countermovement jumps, and (3) the Y-balance test. Asymmetry indices were calculated for all performance measures. The Pre-PHV players showed greater asymmetry in S10_drib, COD_drib, and COD_drib-Deficit than Circa- and Post-PHV (p < 0.05). The S10_drib-Deficit asymmetry was higher in Pre-PHV players than that of Circa-PHV players (p = 0.038), while Post-PHV players had lower COD_drib asymmetry than Circa-PHV players (p = 0.016). Balance asymmetry was greater in Post-PHV players than their counterparts (p < 0.05). Kappa coefficients showed fair to moderate agreement between asymmetry directions in S10_drib and COD_drib, and between their respective deficits, indicating task-specific asymmetry consistency. These findings underscore the need for maturation-specific training strategies, with early-maturing players benefiting from targeted neuromuscular training, while older players should focus on balance and sport-specific drills to manage asymmetry and injury prevention.

AI-based chatbots are increasingly used to design training programs, but their effectiveness for elite athletes is unclear. This study assessed ChatGPT-4's ability to generate weekly training plans for elite swimmers and sprinters. Twenty-three coaches and thirty-six athletes rated the AI-generated plans using a 5-point Likert scale in three areas: weekly frequency, intensity adjustments, and training structure. Seven intensity zones were analyzed: A1 (endurance/recovery), A2 (extensive aerobic), B1 (intensive aerobic), B2 (aerobic-anaerobic transition), C1 (anaerobic threshold), C2 (anaerobic-lactate), and C3 (maximal sprint intensity). Coaches gave neutral-to-positive ratings (3.6 for distance swimmers, 3.7 for sprinters), while athletes were more critical (2.8 and 3.1, respectively). AI-generated plans performed well in low-intensity zones (A1) but had shortcomings in moderate-intensity (A2, B1-B2: long repetitions, excessive sets, insufficient recovery) and anaerobic zones (C1: excessive frequency for swimmers; C2-C3: insufficient frequency for sprinters). No significant differences emerged between plans for swimmers and sprinters (p=0.596), but A2, B1, and B2 showed greater discrepancies (p < 0.001). Rating reliability was moderate for coaches (ICC=0.609) and low for athletes (ICC=0.369). Older coaches and male athletes rated the plans lower, while those with national-level experience were more favorable. While 65% of coaches found the plans usable with minor modifications, only 27.8% of athletes agreed, 47.2% requested major changes, and 25% rejected them. ChatGPT-4 is useful for simple training plans but requires human supervision for complex periodization, particularly in high-intensity zones.

This study aimed to compare the acute biomechanical effects of three distinct sprint-specific priming strategies - resisted sprinting, assisted sprinting (i.e., overspeed), and technical wicket drills - on neuromechanical performance during 50-m sprint trials in elite youth sprinters. Twelve nationally ranked female youth sprinters (17.3 ± 0.8 years) participated in a randomized, repeated-measures protocol. Each athlete performed baseline 50-m maximal sprints, followed by three separate priming interventions, with performance re-evaluated at 24 h and 48 h post-activation. Key outcome measures included 50-m sprint time, reactive strength index (RSI), ground contact time (GCT), flight time (FT), step length, step frequency, duty factor, and asymmetry metrics. Data were analyzed using repeated-measures ANOVA, principal component analysis (PCA), k-means clustering, and machine learning classifiers. Assisted sprinting produced the greatest improvements in RSI (+0.13) and the largest reductions in GCT (-16 ms) at 48 h post-activation (p < 0.001). Resisted sprinting significantly increased step length (+0.09 m), while technical drills improved interlimb asymmetry and mediolateral control. PCA revealed two primary adaptation domains: PC1 (RSI, GCT, FT) and PC2 (interlimb asymmetry, mediolateral sway, and step frequency). Machine learning models (AUC = 0.83-0.85) identified the priming strategy, baseline asymmetry, and step frequency as the strongest predictors of ≥ 10% improvement in RSI. Sprint priming strategies elicited distinct neuromechanical responses that can be assessed during 50-m sprint trials. The overspeed protocol most effectively enhances force-time capacity and sprint performance, whereas technical drills primarily improve coordination. Integrating multivariate modeling facilitates the individualized prescription of priming protocols, offering a flexible and evidence-based approach to sprint optimization and athlete development.

The literature on nutrition in soccer has extensively focused on adult male and female soccer players, while knowledge regarding nutritional issues in youth soccer players remains limited. This review aims to summarize the findings related to nutritional habits and ergogenic aid practices among male youth soccer players. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) Checklist, four databases were consulted on September 17, 2024. Studies that included youth soccer players and examined daily energy intake or expenditure, as well as the effects of ergogenic aids on performance, met the eligibility criteria for this review. In total, 42 studies were considered. Among these, 22 studies focused on energy expenditure and dietary intake, while 20 studies investigated the effects of ergogenic aids on performance. Overall, a negative energy balance was observed; however, after adjusting for the underestimation of energy intake, an adequate intake compared to energy expenditure was found in this review. Additionally, carbohydrate intake tended to decrease with age, while protein intake remained stable throughout adolescence. The topic of macronutrient periodization in youth players requires further research, as no data is currently available regarding macronutrient intake. Additionally, data concerning the effects of ergogenic aids on performance is limited due to variability in methodological procedures. Nevertheless, caffeine and creatine appear to have a positive effect on physical capabilities. This review provides reference data for nutritionists working with youth soccer players and highlights the need for future research in this area.

We aim to investigate the relationship between sleep quality, psychological health, and quality of life (QOL) in highly trained athletes. Elite athletes (n = 118, 20.1 ± 0.64 years; 39 females; 50 world class; 102 aged ≤ 25 years; and 76 practicing individual sports) responded to the Pittsburgh sleep quality index (PSQI), insomnia severity index (ISI), Epworth sleepiness scale (ESS), Depression, anxiety and stress scale (DASS), world health organization QOL (WHOQOL), and bespoke questions related to sleep hygiene. High percentages of the sample reported low or very low sleep quality (62%), moderate or excessive daytime sleepiness (51%), sleeping 7 hours or less (60%), and moderate or severe insomnia (16%), implying a modest sleep health. Female athletes reported higher PSQI (p < 0.05; d = 0.25), ESS (p < 0.05; d = 0.37) and DASS (p < 0.05; d = 0.27) scores compared to males. Young athletes (i.e., ≤ 25 years) reported higher PSQI (p < 0.05; d = 0.49) and DASS (p < 0.05; d = 0.34) scores compared to older athletes (i.e., > 25 years). Individual-sport athletes reported higher ESS (p < 0.05; d = 0.37) and lower QOL (p < 0.01; d = 0.51) scores compared to team-sport athletes. Higher DASS scores were associated with higher PSQI (t = 3.68; β = 0.3) and ISI (t = 4.78; β = 0.36) scores. Lower physical health (i.e., sub-scale of WHOQOL) was associated with higher DASS (t = -5.01; β = -0.42) and ISI (t = -8.02; β = -0.61) scores. Higher PSQI scores contributed to lower WHOQOL scores (t = -4.81; β = -0.41). In summary, the current study highlights reciprocal relationships between low sleep quality, low mental health and low QOL. Elite athletes (especially sub-groups of female, individual, and young athletes) showed a low sleep quality, potentially affecting their physical and psychological health and QOL.

On January 1, 2024, a nationwide ban on sales of energy drinks (EDs) to individuals under 18 came into effect in Poland. The aim of this study was to compare ED consumption, motives, and contexts of use before and after implementation of the sales ban. Two studies with similar methodology were conducted in independent samples: the first in 2022 (n = 1530, adolescents participating in extracurricular sports activities, aged 10-14 years) and the second in 2025 (n = 1083, adolescents from Handball Training Centres, aged 11-15 years). Both studies were anonymous, included participants from all provinces and applied the computer-assisted web interview method. The prevalence of ED consumption among adolescents decreased significantly from 46.4% in 2022 to 19.1% in 2025 following implementation of the sales ban for minors (p < 0.001; OR = 0.27, 95%CI: 0.23-0.33). Before and after the ban, the percentage of ED consumers increased with age. Taste and consuming EDs with friends were the most frequently cited motives and circumstances in both studies. The significant decline in the proportion of ED consumers suggests that the implemented policy may have been effective, albeit to a limited extent. The ban did not alter the circumstances and motives for consumption. To our knowledge, this is the first study to directly compare ED consumption before and after implementation of such a policy among physically active adolescents. Research on a representative youth sample, including adolescents who do not train, is needed to assess the scale of the problem and the effectiveness of the sales ban.

We examined the long-term effects of recreational football training on bone mineralization, osteogenic activity, and physical function in women during the menopause transition. 25 women (45 ± 4 yrs at recruitment) were randomized into an exercise group (EXE; n = 12) completing 1-h football training sessions on average 1.7/wk for a consecutive 9-yr period or an inactive control group (CON; n = 13). Pre and post, we measured bone mineralization and lean body mass, plasma bone turnover markers, and sprint performance. Significant time × group interactions were for leg BMD, leg BMC, femur shaft BMD, CTX-I, PINP, leg lean mass, and sprint performance (all p < 0.01), favoring the exercise group. Leg bone mineral density (BMD) decreased (P = 0.002) by 0.05 g/cm² [-0.08;-0.02] in CON, but was maintained in EXE, resulting in a higher leg BMD in EXE than CON (P = 0.02). Leg bone mineral content (BMC) increased in EXE (time × group, P = 0.005) resulting in a 56 g [4;108] higher (P = 0.04) total leg BMC in EXE compared to CON. A between-group effect existed in favor of EXE for femur shaft BMD (time × group, P = 0.005). Plasma CTX-I and PINP increased (both P = 0.001) by 95% [43;147] and 64% [29-100] following EXE only (time × group, P = 0.003 and 0.02). Leg lean mass increased (P < 0.001) by 1.5 kg [1.0;2.1] in EXE (time × group, P = 0.006). Finally, sprint performance was maintained in EXE but declined (P < 0.001) by 10% [5;14] in CON (time × group, P = 0.002). Recreational football training (on average 1.7 sessions per week) over 9 years preserves leg bone health, muscle mass and functional capacity in women during the menopause transition.