Search Results (3,392)

Background: Creatinine normalization is the default adjustment for urine dilution in spot-urine monitoring of athletes, yet its appropriateness is seldom tested in field data. We tested whether it removes or introduces concentration dependence across a panel of urinary analytes in soccer players training in extreme heat and whether raw versus normalized values change the inferred response. Methods: Sixteen male soccer players (age 19.9 ± 0.8 y) provided spot urine at three daily time points (morning, pre-training, post-training) over six training days in Riyadh, Saudi Arabia. Sodium, potassium, chloride, calcium, magnesium, glucose, urea nitrogen, uric acid, total protein, and creatinine were measured. For each analyte we quantified its scaling exponent with creatinine, the correlation of raw and normalized values with creatinine, and the within-day pattern on raw versus normalized values using linear mixed-effects models. Results: Urinary creatinine varied 22.7-fold (coefficient of variation 39%). Only protein and glucose scaled proportionally to creatinine (exponents ≈1.0) and normalized cleanly (ratio–creatinine r = −0.06 and −0.21). The remaining seven analytes, including all electrolytes, scaled weakly (exponents 0.16–0.49), so normalization over-corrected them, producing strong negative ratio–creatinine correlations (uric acid −0.74, sodium −0.59, chloride −0.55). For four of nine a the inferred within-day response differed in direction or significance between raw and normalized values; restricting creatinine to the recommended 0.3–3 g·L⁻¹ range attenuated but did not abolish the over-correction. Conclusions: Creatinine normalization suited protein and glucose but over-corrected every electrolyte and could reverse inferred responses. In this setting of hot-environment team-sport athletes, creatinine normalization should not be assumed adequate for electrolytes, which instead warrant interpretation against an independent index of urine concentration such as osmolality or specific gravity. Full article

Monitoring physiological responses to intensified training is critical in elite sport, yet evidence in world-class kayak paddlers remains limited. To assess biochemical and hematological acute responses during an intensified training microcycle in an elite flat-water kayaker, a 35-year-old Olympic-level kayaker was monitored across two consecutive 7-day microcycles (pre-intensified and intensified). During the intensified microcycle, fasting venous blood samples were collected over five consecutive mornings. Hematological, biochemical, and hormonal markers were analyzed using standardized laboratory procedures. Training intensification induced marked but physiological changes. From Monday to Tuesday, leucocytes increased from 5.7 to 7.3 × 10⁹/L (+28%), while creatine kinase (CK) rose from 291 to 602 U/L (+107%) and remained elevated (579–604 U/L). Serum iron decreased from 131 to 88 µg/dL (−32.8%) and remained below baseline throughout the microcycle. Triglycerides declined from 63 to 52 mg/dL (−17.5%) and stabilized thereafter. AST increased from 33 to 41 U/L (+24.2%) with minor fluctuations. Across the microcycle, cortisol rose from 522 to 575–578 nmol/L (+10–10.7%), whereas testosterone remained stable (29.4–31.2 nmol/L). Epinephrine increased from 13 to 37 ng/L (+184.6%). Erythrocytes, hemoglobin, and C-reactive protein remained stable. The intensified microcycle elicited substantial but controlled physiological perturbations, reflecting increased muscle stress and systemic load without evidence of maladaptation. Full article

As urban renewal progresses, transforming old industrial plants into sports service complexes has become a prevalent strategy to revitalize urban stock space. To evaluate the actual performance of this spatial reproduction from the users’ perspective, this study analyzes 3702 consumer reviews from five typical Chinese sports service complexes using an interdisciplinary text-mining framework. We employ the LDA topic model to extract core dimensions of consumer concern and utilize the DistilBERT model for fine-grained, sentence-level sentiment computation. The results reveal that consumer attention spans five key topics: venue services, cultural business districts, sports training, industrial integration, and heritage utilization. Critically, the sentiment analysis uncovers a structural paradox: while topics associated with cultural and heritage utilization trigger highly positive emotions and strong place identity, core functional modules like sports training and venue services generate substantial negative feedback. This disparity highlights a profound friction between rigid historical industrial architectural structures and the flexible demands of modern servicescapes, reflecting a clear path dependency in spatial transformation. Based on these theoretical and empirical findings, we propose targeted optimization strategies, including the structural reconstruction of training services and the flexible upgrading of basic venue facilities, to transition these complexes from initial physical construction toward long-term, service-oriented operation. Full article

Heart rate variability (HRV) monitoring is commonly used in sport and exercise science to assess recovery, training adaptation, and performance readiness. However, the routine reporting of numerous HRV metrics with substantial conceptual and physiological overlap has created inconsistency regarding which indices should be prioritized for applied monitoring. This narrative review synthesizes the contemporary literature to provide practical recommendations regarding HRV metric selection in applied monitoring, with particular emphasis on whether the root mean square of successive differences between adjacent normal-to-normal intervals (RMSSD) may serve as the primary metric for routine HRV monitoring in many healthy sport and exercise populations. RMSSD demonstrates several characteristics favorable for applied monitoring, including strong physiological relevance, favorable reliability, compatibility with ultra-short recording durations, relative robustness during spontaneous breathing, computational simplicity, and suitability for longitudinal monitoring frameworks. Although additional HRV metrics remain valuable for addressing specific physiological, mechanistic, or research questions, the current evidence supports RMSSD as the primary metric for routine HRV monitoring in many sport and exercise settings. Full article

Background. Recent advances in data systematization have enabled the development of machine learning models to evaluate performance in elite sports; however, studies are needed to analyze the performance of professional players in relation to their playing position. Objective. To analyze the performance of professional soccer players who competed between 2017 and 2024 by applying a multilevel classification approach that integrates different machine learning algorithms. Materials and Methods. We analyzed 9088 player-seasons from professional players during the 2017–2024 seasons. These data were extracted from standardized databases on sports performance analysis belonging to the following leagues: LaLiga (Spain), Premier League (England), Bundesliga (Germany), Serie A (Italy), and Ligue 1 (France). The final sample, distributed by performance level, was as follows: elite players (n = 1818; 20%), mid-level players (n = 2727; 30%), and low-level players (n = 4543; 50%). The average age of the players analyzed was 26.1 ± 4.0 years, distributed across three outfield playing positions: center backs (CB), central midfielders (CM), and strikers (ST); goalkeepers were excluded because the dataset contains no goalkeeper-specific performance metrics. Results. Under a leakage-controlled protocol (the label-defining indicators were excluded from the predictors and the train/test split preceded all preprocessing), a linear model (logistic regression) achieved the best overall performance (mean macro-F1 = 0.729), ahead of ensemble and kernel-based methods; this indicates that, once target leakage is removed, the classification does not require non-linear models. Strikers (ST) were the most separable position (best macro-F1 = 0.818, area under the receiver operating characteristic curve [AUC-ROC] = 0.948) and center backs (CB) the most difficult (macro-F1 = 0.602, AUC-ROC = 0.791), with midfielders (CM) intermediate (macro-F1 = 0.770, AUC-ROC = 0.916). Conclusions. The results confirmed that performance structures differ substantially depending on the position in the field, supporting the use of position-specific analytical strategies. In this context, the combination of position-stratified dimensionality reduction, handling of imbalance, and explainable artificial intelligence allowed for the identification of interpretable performance patterns associated with the profiles of elite, mid-level, and low-level players. Full article

Aim: While voluntary Islamic intermittent fasting (IF) of three consecutive days (mimicking practices such as Ayyam al-Bid) may be observed by Muslim athletes, its short-term effects on cognitive function and sleep quality in adolescent team-sport athletes remain unexamined. This study investigated the impact of three successive days of dawn-to-sunset IF on memory, attention, psychomotor vigilance, and subjective sleep quality in young male soccer players. Methods: A quasi-experimental, parallel-group design was employed. Thirty-five male soccer players (age: 15.6 ± 0.8 years; body mass: 55.07 ± 6.53 kg) were allocated to an IF group (n = 17) or a non-fasting control group (n = 18). The fasting protocol comprised approximately 14 consecutive hours of complete food and fluid abstinence per day (from 04:40 to 18:36, with daily variations of −3 min for the dawn and +2 min for the sunset, local time). Cognitive function was assessed using the CogniFit Cognitive Assessment Battery (CAB) and the Psychomotor Vigilance Test (PVT), and subjective well-being was quantified via the Hooper Index. Both assessment sessions were conducted between 14:00 and 17:00 to control for diurnal variation. Results: The Group × Time interaction for single-item subjective sleep quality reached nominal significance at the unadjusted threshold (Z = 2.18, p = 0.029, r = 0.37) but did not survive Bonferroni correction for the four Hooper Index comparisons (α = 0.0125); this result is therefore interpreted as hypothesis-generating only, reflecting a within-group deterioration in the control group (p < 0.05) alongside a non-significant marginal improvement in the fasting group. No statistically significant Group × Time interaction was detected for any memory subdomain (all p ≥ 0.419, r ≤ 0.14), attention component (all p > 0.176, r ≤ 0.23), or PVT parameter (all p > 0.192, η²p/r ≤ 0.22) under the present study conditions. Within-group improvements in memory and attention observed in both groups were consistent with test–retest learning effects. Conclusions: No statistically significant Group × Time interaction was detected for memory, attention-related executive functions, or psychomotor vigilance in young male soccer players under the present study conditions; the study was not designed as an equivalence or non-inferiority trial and cannot exclude effects smaller than the targeted medium magnitude, alongside a nominally divergent but statistically uncorrected sleep quality trajectory relative to non-fasting controls, which should be interpreted as hypothesis-generating pending replication. These findings provide preliminary, hypothesis-generating evidence that no statistically significant cognitive or psychomotor impairment was detected under the present study conditions; because the study was not designed as an equivalence or non-inferiority trial, compatibility between short-term voluntary IF and adolescent athletic training cannot be inferred from the absence of a significant interaction alone. Full article

Background: Muscle health decline is a major concern in postmenopausal women; however, most interventions have focused on exercise as an isolated component. It remains unclear whether embedding exercise within a broader lifestyle framework enhances muscle-related outcomes. Methods: A total of 100 postmenopausal women took part in this randomized controlled trial and were randomly assigned to three groups: Nordic walking combined with high-protein intake and time-restricted eating (NW+HP+TRE, n = 36), Nordic walking combined with time-restricted eating (NW+TRE, n = 33), and a control group (n = 31). The intervention lasted 12 weeks. The primary outcome was handgrip strength, and the secondary outcomes included physical performance (6 m gait speed and five times chair-stand time) and lean mass-related measures. Adherence to all intervention components was monitored throughout the study. Results: During the intervention, four participants did not complete the post-intervention assessment, resulting in 96 participants being included in the final analysis. Handgrip strength improved in both intervention groups, with the largest increase observed in the NW+HP+TRE group. Physical performance outcomes showed a similar pattern. In contrast, the NW+TRE group showed less favorable changes in lean mass-related measures, whereas the control group showed minimal overall changes. Adherence to Nordic walking, time-restricted eating, and protein intake was high in the intervention groups. Conclusions: A Nordic walking-based integrated lifestyle intervention was associated with a more favorable overall pattern of change in muscle strength, physical performance, and lean mass-related outcomes in postmenopausal women. These findings should be interpreted as differences between intervention packages rather than as evidence for the isolated effect of any single lifestyle component. Further research is needed to examine the long-term sustainability of such interventions and to clarify the contribution of individual components. Full article

Background: Sports training induces functional and structural adaptations that may influence body composition, particularly during adolescence when growth and maturation are still occurring. Although anthropometric characteristics have been extensively studied within individual sports, comparative analyses among different sport categories remain limited. The aim of this study was to compare body composition characteristics among athletes participating in individual, team, and combat sports within a Spanish Sports Technification Program. Methods: A total of 118 young athletes (62 males and 56 females) from the Valencian Sports Technification Centre participated in this cross-sectional study. Participants were classified into three sport categories: individual sports (athletics, swimming, and triathlon), team sports (handball and volleyball), and combat sports (karate and taekwondo). Anthropometric assessment was performed according to the International Society for the Advancement of Kinanthropometry (ISAK) protocol. Body composition variables, including fat mass, muscle mass, and bone mass, were estimated using established anthropometric equations. Statistical analyses were performed using non-parametric tests, with significance set at p < 0.05. Results: After adjustment for multiple comparisons, significant differences remained between sport categories for several body composition indicators. Athletes from the individual sport group showed a higher muscle mass percentage and lower body fat percentages estimated using the Withers, Faulkner, and Carter equations than those from the team sport group. Similarly, estimated body fat percentages were lower in the individual sport group than in the combat sport group across all three equations. Team sport athletes presented higher absolute fat and muscle mass than combat sport athletes. However, some differences identified in the initial analyses, including fat mass and bone mass percentage between the individual and team sport groups and muscle mass percentage between the team and combat sport groups, did not remain statistically significant after adjustment for multiple comparisons. Conclusions: Body composition characteristics differed among the groups of young athletes participating in the specific individual, team, and combat sports included in this study. Within this cohort, athletes from the individual sport group generally exhibited lower body fat levels than those from the team and combat sport groups, whereas differences were also observed in other anthropometric characteristics. These findings should be interpreted within the context of the specific sports included and should not be generalized to individual, team, or combat sports as a whole. The findings may assist coaches, sports scientists, and health professionals in the monitoring and development of young athletes participating in similar sports and development programs. Full article

This study investigated the effects of alpha-band EEG neurofeedback on load-specific lower body strength performance in competitive judokas and examined whether training status modulates neuromuscular adaptation. Twenty-four male athletes (advanced vs. intermediate level) completed 15 neurofeedback sessions targeting the Frontal Alpha Asymmetry Index (FAAI) using real-time EEG from F3/F4 electrodes. Squat performance was assessed across five relative loads (35–100% 1RM) pre- and post-intervention. Key outcomes included ∆Reps at each intensity, EEG changes (∆FAAI, ∆F3, ∆F4), and a composite neural efficiency index (∆Reps/∆FAAI). Statistical analyses included RM-ANOVA, MANOVA, and ANCOVA with FAAI baseline as a covariate. Neither group showed significant within-group performance improvements across load conditions, and multivariate analysis revealed no significant group effect on EEG change outcomes (Wilks’ Λ = 0.930, p = 0.688). None of the individual EEG change metrics differed significantly between groups (∆FAAI, ∆F3, ∆F4; all p > 0.28). Efficiency indices likewise did not differ significantly by group (all p > 0.32), and FAAI baseline did not predict performance transfer. Despite uniform intervention exposure, cortical EEG changes did not differ significantly between experienced and Intermediate-level athletes, and squat performance remained load invariant in both groups. Because the design did not include a placebo or non-neurofeedback control condition, and given the small sample (n = 12 per group) and the non-significant multivariate effect, these findings should be regarded as preliminary and associative rather than causal. They suggest that alpha-band neurofeedback was not associated with training-status-dependent EEG changes over this protocol, and that cortical changes did not translate into measurable gains in maximal strength output under progressive loading. Further studies using placebo-controlled designs and larger samples should extend training duration and consider multimodal interventions to bridge cortical gains with functional strength improvements in elite sport contexts. Full article

Exercise and sports metabolomics provide a systems-level approach to characterizing how acute exercise, training adaptation, nutrition, recovery, and environmental stress reshape human metabolism. By profiling metabolites related to substrate utilization, mitochondrial function, redox balance, inflammation, muscle stress, and recovery kinetics, these approaches can reveal pathway-level responses that conventional single biomarkers cannot capture. However, many exercise-responsive features remain difficult to interpret because of incomplete chemical identification, uncertain annotation confidence, limited quantitative reproducibility, variable pre-analytical control, inconsistent data processing, and insufficient biological validation. This narrative review examines recent advances in exercise and sports metabolomics, with emphasis on LC–MS, GC–MS, NMR spectroscopy, IMS–MS, and CE–MS workflows; platform selection; metabolite annotation and identification; pathway-level interpretation; and evidence requirements for candidate-panel development. Exercise-responsive metabolites should be interpreted as context-dependent pathway signals rather than isolated indicators of fatigue, recovery, adaptation, or performance. The review consolidates requirements for sampling, quality control, metadata capture, repeated-measures analysis, and external validation within an evidence-readiness roadmap. Wearable biochemical monitoring, AI-assisted analysis, and multi-omics integration may support future applications, but their value depends on analytical robustness, external validation, and physiological interpretability. Exercise and sports metabolomics should therefore progress from descriptive feature discovery toward reproducible, quantitatively reliable, and biologically validated pathway-level interpretation. Full article

Background/Objectives: Prolonged sedentary behavior is associated with adverse cardiometabolic risk, but the acute metabolic effects of interrupting sitting remain incompletely quantified in apparently healthy populations. The objective was to evaluate the acute effects of interrupting prolonged sitting on glucose, insulin and lipid metabolism and to identify potential protocol-level moderators. Methods: We conducted a three-level meta-analysis of randomized crossover trials comparing structured sitting interruptions with uninterrupted sitting in apparently healthy participants, an approach used to account for the statistical dependency among multiple effect sizes reported within individual studies. PubMed, Embase, Web of Science, Scopus and Cochrane Library were searched from inception through March 2026. Standardized mean differences (Hedges’ g) were calculated using random-effects models with robust variance estimation. Subgroup analyses and meta-regression examined interruption modality, intensity, frequency and duration. Certainty of evidence was assessed using GRADE. Results: The evidence base comprised 25 publications representing 23 independent cohorts; primary outcome analyses included 23 cohorts (135 effect sizes). Sitting interruption produced small but significant reductions in glucose (g = −0.28, 95% CI −0.49 to −0.08; PI −1.15 to 0.59) and insulin (g = −0.22, 95% CI −0.36 to −0.07; PI −0.51 to 0.07). No significant effect was observed for triglycerides (g = −0.04, 95% CI −0.14 to 0.07), whereas the exploratory estimates for non-esterified fatty acids (NEFA) and C-peptide were inconclusive. Subgroup analyses did not identify any statistically significant moderators of glucose, insulin or triglyceride responses; all subgroup estimates drawn from fewer than five independent cohorts are exploratory and hypothesis-generating. Meta-regression identified no statistically significant linear moderators. Certainty of evidence was low for all three primary outcomes (glucose, insulin and triglycerides) and very low for the exploratory outcomes (NEFA and C-peptide). Conclusions: Interrupting prolonged sitting may produce modest acute improvements in glucose and insulin responses in apparently healthy participants but does not reliably affect triglyceride metabolism. Given the low certainty of the current evidence, sitting interruption may be considered a low-burden adjunctive behavior for reducing uninterrupted sitting time. However, the current evidence primarily supports the hypothesis that interrupting prolonged sitting is a promising behavioral strategy rather than an evidence-based clinical recommendation, and its metabolic effects require confirmation in adequately powered, higher-quality trials. Full article

Background: This study aimed to compare changes in motor coordination associated with two different motor practice models—multisport and single-sport soccer training—in children, without implying causal effects of one training context over the other. Methods: A quasi-experimental pre–post study (T0–T1) was conducted over 10 weeks in non-randomized, pre-existing groups. A total of 143 children (mean age: 6.21 ± 0.55 years; 107 males) were allocated to a Multisport Group (MG; n = 79) and a Single-sport Group (SG; n = 64). Motor coordination was assessed using the Körperkoordinationstest für Kinder (KTK), and raw scores (RAW SCORE) were used for analysis. Statistical analyses included t-tests, change-score (Δ) and effect-size analyses, and two-way repeated-measures ANOVA. Results: Both groups showed significant improvements over time (p < 0.001; d = 0.75 for MG, d = 0.77 for SG). However, the MG showed significantly greater improvements than the SG (Δ = 16.68 ± 6.14 vs. 12.28 ± 4.08; p < 0.001; d = 0.83). At T1, the SG still showed slightly higher absolute RAW SCORE values than the MG (p = 0.049; d = −0.33), although this between-group difference was markedly reduced compared to baseline (d = −0.59). The ANOVA revealed a very large effect of Time (F(1,141) = 1092.31, p < 0.001, η²p = 0.886), a small-to-medium effect of Group (F(1,141) = 7.51, p = 0.007, η²p = 0.051), and a large Time × Group interaction (F(1,141) = 24.18, p < 0.001, η²p = 0.146). A sensitivity analysis (ANCOVA) confirmed that, after adjusting for baseline scores, sex, and anthropometric variables, the Multisport group showed significantly higher adjusted T1 scores than the Single-sport group (adjusted mean difference = 3.96 points, 95% CI: 1.93–5.99), reversing the direction observed in the unadjusted T1 comparison. Given the non-randomized design and baseline group differences, findings reflect observed associations rather than causal effects. Conclusions: Both practice models were associated with improved motor coordination, with multisport participation associated with greater observed change over 10 weeks. These findings are consistent with a possible role of diversified motor experiences in coordination development, though this study cannot establish causality. Full article

This paper presents a novel approach for estimating 3D human pose from monocular video sequences in underwater scenarios, tackling the unique challenges posed by water refraction, body occlusion, low image quality and illumination distortion in underwater environments. Leveraging both 2D keypoint extraction and parametric model estimation, our method operates in a two-stage framework including preprocessing and optimization. In the preprocessing stage, a Part Attention Regressor (PARE) is adopted to dynamically estimate SMPL human body parameters, particularly adept at handling occlusions common in underwater scenarios. Additionally, a 2D keypoint detector, employing YOLO for bounding box detection and HRNet for keypoint regression, enhances feature extraction despite underwater image challenges. In the optimization stage, we propose an underwater variational autoencoder (UW-VAE), which adopts a data-driven strategy to learn the biomechanical prior distribution of underwater human poses and implicitly correct unreasonable pose parameters caused by refraction and occlusion. The optimization process incorporates constraints aligning final SMPL models with detected 2D keypoints, minimizing disparity between adjusted and original SMPL models, and ensuring temporal consistency. Furthermore, to address the scarcity of annotated underwater datasets, we build a full pipeline to generate synthetic underwater datasets with complete annotations based on UW-VAE. Experimental results on the SwimXYZ synthetic dataset show that our method achieves 51.60% PCK@0.2 and 80.13% PCK@0.5, outperforming state-of-the-art land-based methods across most stroke categories. Validation on real-world underwater swimming datasets demonstrates improved 2D keypoint accuracy after synthetic-data fine-tuning, which provides a new solution for 3D human motion analysis in underwater sports, biomechanical research and swimming training. Full article

Background/Objectives: Hitting the wall (HTW) is a common and performance-limiting phenomenon in marathon running, traditionally attributed to glycogen depletion and reduced carbohydrate availability. However, the persistence of late-race performance collapse despite advances in fueling strategies suggests that HTW may not be explained by a single metabolic mechanism. Instead, HTW may represent a psychophysiological performance-collapse phenomenon arising from the interaction between physiological strain, perceived exertion, pacing regulation, and the athlete’s capacity to preserve function under prolonged stress. Methods: This narrative review aimed to synthesize the physiological and psychophysiological mechanisms contributing to HTW and to propose an integrative durability-based framework for understanding late-race performance deterioration during marathon running. Results: Current evidence indicates that HTW may emerge from the cumulative interaction of metabolic stress, thermoregulatory strain, dehydration, gastrointestinal dysfunction, neuromuscular fatigue, biomechanical deterioration, perceptual responses, and pacing errors. These stressors may progressively increase perceived effort, impair pace regulation, and reduce the athlete’s capacity to preserve physiological function and sustain the intended race pace. Within this framework, durability represents the ability to resist deterioration in physiological characteristics and performance capacity during prolonged exercise and may help explain why runners with similar fitness levels experience different late-race outcomes. Conclusions: HTW should therefore not be viewed simply as running out of fuel. Rather, it may represent the manifestation of reduced durability and psychophysiological dysregulation arising from multiple interacting stressors during marathon running. Strategies aimed at improving durability through marathon-specific training, optimized fueling, gastrointestinal tolerance, thermoregulatory preparation, neuromuscular resilience, pacing regulation, perceptual awareness, and individualized monitoring may reduce susceptibility to HTW. Full article

Background and Objectives: Evidence on the acute effects of caffeine in female team-sport athletes is limited. This study aimed to quantify the acute effects of caffeine on female team-sport athletes across physical performance, sport-specific performance, physiological responses, perceptual responses, and cognitive performance and determine moderators. Methods: PubMed and Web of Science were systematically searched for randomized, placebo-controlled crossover trials of acute, dose-defined caffeine in female team-sport athletes. Effect sizes were expressed as Hedges’ g and synthesized within each domain using a three-level CHE model with CR2 cluster-robust variance estimation and Satterthwaite degrees of freedom; 95% confidence intervals and prediction intervals were reported. Risk of bias (RoB 2), methodological quality (PEDro), and certainty of evidence (GRADE) were assessed. Results: Twenty-six studies were included, comprising 26 randomized, blind, placebo-controlled crossover trials. As a descriptive cross-domain summary, acute caffeine intake showed a small overall effect when all available domains were pooled (Hedges’ g = 0.24, 95% CI 0.13 to 0.35); however, because these domains represent different constructs, domain-specific estimates were considered the primary interpretable findings. For physical performance, caffeine showed a small favorable effect (g = 0.32, 95% CI 0.22 to 0.42), with statistical evidence for repeated sprint ability (g = 0.43), agility or change in direction (g = 0.42), sprint or speed performance (g = 0.39), anaerobic power (g = 0.30), and jumping performance (g = 0.29). For sport-specific performance, the pooled estimate indicated a small favorable effect but did not reach conventional statistical significance (g = 0.36, 95% CI: −0.01 to 0.73). Exploratory sub-indicator analyses, each based on only a few studies, suggested possible favorable directions for sport-specific locomotion or running performance (g = 0.46) and throwing or ball-speed outcomes (g = 0.19), whereas evidence was insufficient for shooting or scoring accuracy. Physiological outcomes were direction-aligned to the value conventionally regarded as favourable for each indicator (i.e., lower heart rate, lactate, and glucose), so that positive values denote the conventionally favourable direction; because the domain aggregates indicators of differing clinical desirability, its pooled value is a descriptive summary only and showed no clear domain-level direction (g = −0.05, 95% CI −0.31 to 0.21). The heart rate submetric showed a statistically detectable difference (g = −0.30), indicating that caffeine increased heart rate, the expected pharmacological response to a stimulant rather than an adverse effect; there were no clear effects on blood lactate or blood glucose. Perceptual responses improved modestly (g = 0.42), largely through reduced rating of perceived exertion (g = 0.35). Cognitive performance, based on only four studies with low degrees of freedom and wide uncertainty, showed a nonsignificant direction (g = 0.37) with no clear evidence for reaction time or cognitive accuracy, and these data should not be interpreted as showing that caffeine improves cognitive performance in female team-sport athletes. Exploratory moderator analyses did not provide statistically reliable evidence of moderation by caffeine dose, timing of intake, formulation or source, sport type, competitive level, habitual caffeine intake, or blinding status. Conclusions: Available evidence most consistently supports small, outcome-specific benefits of acute caffeine for physical performance and reduced perceived exertion. Evidence for sport-specific skills and cognitive outcomes remained uncertain, based on few studies per outcome and not supporting a general benefit. Current data do not support dose-, timing-, formulation-, habitual-intake-, sport-, or population-stratified recommendations. Future trials should be adequately powered, prospectively report menstrual-cycle phase, hormonal-contraceptive use, habitual caffeine intake, and adverse symptoms, and verify the integrity of blinding. Full article