Biology of Sport最新文献

Basketball performance is influenced by technical-tactical factors, but their effects across different contexts are not well understood in women's basketball. This study analyzed the influence of match outcome (win, lose), match location (home, away), and playing positions (guard, G; point-guard, PG; small-forward, SF; power-forward, PF; center, C) on Key Performance Indicators (KPIs) in Spanish female basketball players. Data from 1786 games involving 897 players (33243 cases) across 10 consecutive seasons were analyzed (2013-2022). Sixteen normalized KPIs (standardized by minutes played) were evaluated using linear mixed modeling with individual player ID as a random factor, controlling for nested data structure (ICC > 0.10, p < 0.001). Fixed effects included playing position, match outcome, match location, and their interactions. Results revealed position-specific patterns: centers and power-forwards achieved significantly higher values in 2-point shots, offensive rebounds (C > PF > SF > PG=G), and blocks (C > PF > SF=PG=G), while guards obtained higher 3-point shooting (G=PG > SF=PF=C), assists (G > PG > SF=PF=C), and steals (G=PG > SF=PF=C) with large effect sizes. Winning teams significantly outperformed losing teams, with the largest differences in points, assists, and reduced turnovers. Home teams demonstrated significant advantages in assists, blocks, and reduced turnovers. Interaction effects revealed that guards benefited most from playing at home in assists, while centers showed the greatest home-court advantage in blocks. Position-outcome interactions showed centers contributed most to winning through 2-point shooting and rebounding, while guards impacted success through playmaking and reduced turnovers. Technical-tactical performance varies substantially by position, match outcome, and location. Coaches should tailor training to leverage positionspecific strengths while developing strategies to overcome positional weaknesses, especially for away games.

This study aimed to compare the effect of three velocity loss (VL) thresholds - 0% (VL0: one repetition per set), 25% (VL25), and 50% (VL50) - on strength gains, neuromuscular adaptations, and muscle hypertrophy during the bench press (BP) exercise. Forty-nine resistance-trained women were randomly assigned to three groups that followed an 8-week (16 sessions) BP training program using intensities ranging from 70% to 85% of 1-repetition maximum (1RM). Training groups differed in the VL achieved in each set (VL0, VL25, and VL50). Assessments performed before and after the training program included: 1) muscle thickness of the triceps brachii (TB); 2) maximal isometric test; 3) progressive loading test; and 4) fatigue test, all in the BP exercise. Electromyography signal was recorded from TB during these tests. Although all groups obtained significant gains in all strength variables, VL50 showed greater gains in 1RM strength and velocity against heavy loads than VL0 (group × time interaction: P < 0.001 and P = 0.04, respectively). Significant improvements in the force-time variables and electromyography amplitude (P = 0.01, with light loads) were observed exclusively in the VL25 group. Additionally, only VL50 exhibited significant increases in TB muscle thickness (P = 0.01). The greater the VL threshold, the more positive the effects on performance against heavy loads and muscle hypertrophy. Moderate VL thresholds improved the ability to produce force at high velocity and led to positive neuromuscular adaptations. Performing only one repetition per set was enough to improve strength in intermediate-trained women but was insufficient to maximize strength gains.

This study aimed to examine the association between aerobic performance (AP) and match running performance (MRP) in elite soccer players when statistically controlling for playing position and contextual factors. AP was tested at the beginning of the season, including maximal oxygen uptake ( ${\dot{\text{V}}\text{O}}_{2\max }$ ), anaerobic threshold (AnT), maximal aerobic speed (MAS), and Yo-Yo Intermittent Recovery Test Level 2 (Yo-Yo IRT2) score. MRP was measured using GPS over a competitive half-season for a total of 216 match performances in elite soccer players, divided into central backs (CBs), full backs (FBs), central midfielders (CMs), wide midfielders (WMs), and strikers. The lowest AP measures were noted among the CBs, while the highest ${\dot{\text{V}}\text{O}}_{2\max }$ , AnT, and MAS were recorded among the CMs, CMs and FBs, and FBs, respectively. The CBs had the lowest total distance (TD), high-speed running (HSR; 19.8-25.1 km · h^-1) distance, and high-intensity running (HIR; > 19.8 km · h^-1) distance; the CMs recorded the greatest TD; and the FBs and WMs covered the greatest HIR distance. Despite the differences in AP and MRP among the players, AP is correlated with MRP independently of the playing position and contextual factors. Higher AP measures were positively associated with the TD, and higher Yo-Yo IRT2 scores were also positively associated with the HSR and HIR distances. The strongest predictors for TD were ${\dot{\text{V}}\text{O}}_{2\max }$ and AnT. In conclusion, a higher AP, irrespective of playing position, makes it possible to achieve greater MRPs. This study emphasized the value of integrating AP metrics into individualized training and player role management in elite soccer.

Traditional soccer training relies on repetitive drills, while modern approaches emphasize personalized strategies that better suit individual player development needs. This study examined the effects of Small-Sided Games (SSGs) alone and in combination with Differential Learning (SSG + DL) on physiological responses, tactical behaviors, and technical skills enhancement of soccer players. Twenty male soccer players participated in this randomized controlled trial, assigned to either a control group (SSG, n = 10, age: 19.4 ± 1.07 years) or an intervention group (SSG + DL, n = 10, age: 18.2 ± 0.91 years). Physiological responses (heart rate, blood lactate, RPE), tactical behaviors, and technical skills were assessed before and after an 8-week training program (four sessions weekly). Large main effects of Time were found for technical/tactical skills including possession (η² = 0.83), passes (η² = 0.86), shots (η² = 0.77), tackles (η² = 0.73), and decisionmaking (η² = 0.92). Medium effects emerged for heart rate (η² = 0.19) and effort (η² = 0.27). Group effects were negligible for physical measures. Significant interaction effects favoring the intervention were found for possession (η² = 0.42), passes (η² = 0.42), tackling (η² = 0.74), and marking (η² = 0.58). The intervention group showed larger improvement effect sizes (g = 0.11-2.61) compared to controls (g = 0.05-1.97). Integration of SSGs with DL significantly enhances tactical behaviors and technical skills in amateur soccer players compared to SSGs alone. These findings provide coaches with a practical framework to develop more adaptable players, particularly valuable for youth teams with limited resources, highlighting the importance of incorporating innovative training methods that emphasize variability and exploration.

We sought to investigate whether the magnitude of differences in cycling critical power between normoxia and hypoxia (∆CP) is associated with fitness level or haematological status in highly trained endurance athletes. Thirty-three triathletes and longtrack speed skaters (11 females) completed two 3-minute CP cycling tests: one in normoxia (F_iO₂ = 20.8%) and the other in normobaric hypoxia (F_iO₂ = 14.2%). This cross-sectional study analysed ∆CP regarding performance, physiological, and haematological indices using correlation and regression analyses. Significant correlations were found between ∆CP and baseline CP in normoxia (r = -0.366, p = 0.047), ${\dot{\text{V}}\text{O}}_{2\max }$ (r = -0.437, p = 0.018), and MCH (r = 0.487, p = 0.012). Only a few significant associations were found between the indices obtained from venous blood sampling and ∆CP, different for females and males. In females, ∆CP was correlated with Hb_mass (r = -0.761, p = 0.017), erythrocyte volume (r = -0.783, p = 0.013), plasma volume (r = -0.745, p = 0.021), and blood volume (r = -0.870, p = 0.002), all established with the CO rebreathing method. The best-performing regression model (R² = 0.501, RMSE = 0.033, p = 0.002, Cohen's F² = 1.004) included MCH, ${\dot{\text{V}}\text{O}}_{2\max }$ , and Hb_mass. A higher fitness level is associated with a greater CP decrease in hypoxia among the homogeneous cohort of highly trained endurance athletes. Haematological status plays a more prominent role in females, and the CO rebreathing method should be considered a preferred approach for assessing haematological status in highly trained athletes.

This study aimed to examine the effects of pre-bedtime smartphone use on sleep quality and athletic performance in soccer players while also investigating potential time-of-day variations. In this randomized controlled crossover trial, 16 male elite-level players were assigned to either use a smartphone for two hours prior to bedtime or read magazines (control), separated by a one-week washout period. Participants completed morning and afternoon performance tests (cognitive and physical assessments) and sleep quality measurements. Nocturnal smartphone use significantly impaired sleep quality, increasing sleepiness after days 3 and 5 (p < 0.01; d=5.74, d=5.72, respectively), decreasing total sleep time, increasing sleep onset latency, and reducing sleep efficiency (all p < 0.01; d=1, d=4.59). Cognitive performance initially showed improved afternoon results, although following five days of smartphone use, this pattern reversed with enhanced morning performance (p < 0.01; d=0.53, d=1.48). Simple and choice reaction times deteriorated significantly in afternoon sessions compared to both baseline and control conditions (p < 0.01; d=0.96-3.47). Physical performance tests revealed decreased jumping ability and slower reactive agility times following five nights of smartphone use, particularly in afternoon sessions (p < 0.01; d=0.85-0.91). Five consecutive nights of pre-bedtime smartphone use impaired sleep quality and both cognitive and physical performance in elite soccer players, with stronger effects in afternoon sessions. These findings emphasize the importance of implementing device-free periods prior to bedtime and potentially adjusting training schedules when evening screen exposure is unavoidable. Future research should explore countermeasures for managing evening device exposure in elite athletes.

The aim of this study was to evaluate the quality of resistance training plans for muscle hypertrophy and maximal strength generated by three large language models (LLMs): GPT-3.5 (via ChatGPT and Microsoft Copilot) and Google Gemini (GG). A total of 10 experienced coaches, each with at least a bachelor's degree in exercise science and at least 2 years of coaching experience, rated these plans on a 1-5 Likert scale based on 27 criteria essential for effective training plan design. The LLMs were accessed on April 30, 2024, with a prompt structure that included key training objectives and the training history of a fictional advanced trainee. Results showed that the overall quality of the LLM-generated training plans was moderate. GG outperformed GPT-3.5 (via ChatGPT and Microsoft Copilot) for hypertrophy-related plans on 2 out of 27 criteria (advanced exercise methods, recovery strategies; p < 0.05), while GPT-3.5 (via Microsoft Copilot) outperformed GG for strength-related plans on 1 out of 27 criteria (testing procedure; p < 0.05). Across all criteria, GG received ratings > 3 more frequently than GPT-3.5 (via ChatGPT and Microsoft Copilot), particularly for general aspects, training principles, and training methods. Differences between hypertrophy- and strength-oriented plans within each LLM were minimal, although GPT-3.5 (via ChatGPT) showed the most inconsistency in ratings. Although LLM-generated plans can serve as an initial framework for hypertrophy and strength development, expert supervision remains crucial to refine these plans, as LLMs cannot account for individual responses to training, safety considerations, and the complex physiological adaptation processes observed by experienced coaches.

This study investigated the effects of ischemic preconditioning (IPC) on performance during highintensity resistance exercise (RE) sessions, as well as the additional effects of inter-set palm cooling (PC) and the potential underlying mechanisms. Twelve resistance-trained men participated in three RE sessions in a randomized order: (1) IPC followed by RE with inter-set PC (15°C for 2.5 minutes), (2) IPC followed by RE, (3) SHAM followed by RE. IPC involved four cycles of 5-minute ischemia/5-minute reperfusion at 220 mmHg on the upper arm, whereas SHAM involved 20 mmHg with a pneumatic cuff. The RE protocol included three sets to exhaustion, consisting of six exercises at 85% of one-repetition maximum. Multiple perceptual parameters were assessed during RE, and blood samples were obtained both before and after four cycles of ischemia/reperfusion as well as after RE. The results indicated that compared with SHAM, IPC significantly increased the total work volume (∆ = 2.6%); the total number of repetitions (∆ = 4.3%); the number of repetitions in specific exercises; and the levels of several arousal indicators, such as norepinephrine levels before RE and arousal level (assessed using the Felt Arousal Scale) during RE (p < 0.05). The IPC + PC combination further outperformed SHAM alone in most parameters (p < 0.05). However, fatigue indicators (rating of perceived exertion and lactate level) did not differ significantly across the protocols. In conclusion, this study suggest that IPC enhances high-intensity RE performance, potentially through increased arousal levels, with PC augmenting exercise performance by amplifying the arousal response.

To synthesise the impacts of napping following normal sleep (NS) or deprived sleep on psychophysiological measures in physically active individuals and athletes. This systematic review and metaanalysis utilized nine databases, including Web of Science, PubMed/MEDLINE, Scopus, SPORTDiscus, Embase, ProQuest Central, Cochrane Library, PsycInfo, and SciElo, to evaluate the effects of napping in physically active individuals and athletes, focusing on psychophysiological measures. The risk of bias in the included studies was assessed using the Cochrane Collaboration's RoB 2.0 tool, while the certainty of evidence (CoE) was evaluated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach. In the 35 studies, 489 participants (athletes or physically active) were studied. Following NS, napping significantly reduced total mood score (standardized mean difference (SMD)=0.61), fatigue (SMD=0.91), rating of perceived exertion (RPE) both during (SMD=1.62) and immediately after exercise (SMD=1.11). Additionally, napping significantly improved perceived recovery (SMD=1.66). There were no significant effects of napping on sleepiness (SMD=1.09), muscle soreness (SMD=1.57), heart rate during exercise (SMD=0.62), and temperature (SMD=0.66). Similarly, following sleep deprivation, there were no significant effects of napping on sleepiness (SMD=1.03) and fatigue (SMD=0.79). The CoE was rated as moderate for RPE during and after exercise following NS, while it was low to very low for the remaining outcomes. Napping has been found to positively impact only fatigue, mood states, perceived exertion, and recovery following NS in physically active individuals and athletes. The low-to-very low CoE requires cautious interpretation, highlighting the need for further napping studies implementing robust methodologies.

The aim of this study was to analyze how the type, location, and severity of injury are associated with the time elapsed since the return to training and matches of male football players to reach fitness values comparable to pre-injury levels. A longitudinal analysis was conducted on 333 male football players from an elite Spanish football club over five seasons (2017/18 to 2021/22). A total of 234 injuries (including medical attention) were included in the analysis. The study focused on hamstring and quadriceps injuries, examining high-speed running, sprint distance, and maximum velocity before and after injury. Results indicated that hamstring injuries significantly impact V_max and HSR, with severe injuries requiring up to five weeks to return to pre-injury levels (V_max: -1.43 km/h, p = 0.01; HSR: -32.90 m, p = 0.04). Quadriceps injuries revealed less impact on performance metrics than hamstring injuries, with only mild injuries resulting in a significant reduction in V_max (-1.18 km/h, p = 0.04) and HSR (-52.70 m, p = 0.01) during the first week post-injury. The findings highlight the importance of injury-specific rehabilitation protocols and the need for tailored training loads to minimise the risk of re-injury and optimise return to performance. This research provides valuable insights for medical and performance staff in elite football, emphasizing the critical role of injury management in maintaining player performance and club success.