BackgroundWomen's futsal has experienced significant growth, highlighting the importance of understanding psychological need satisfaction and burnout as key determinants of athlete well-being. Basic psychological needs satisfaction, according to Self-Determination Theory, and athlete burnout are key constructs in promoting healthy and sustainable sports environments. Foot injuries are also prevalent in high-intensity sports such as Futsal and may be related to psychological outcomes in athletes.ObjectivesThis study aimed to examine the relationship between psychological need satisfaction and burnout in female futsal players, and to explore associations between foot and ankle injuries (podiatric pathology), age, and sport experience with these psychological variables.DesignObservational, cross-sectional, descriptive study.MethodsNinety-four adult female futsal players from first and second national divisions participated. Participants completed a sociodemographic and injury questionnaire, the Athlete Burnout Questionnaire (ABQ), and the Psychological Needs in Sport Questionnaire (PNSQ-15). Injury history included ankle sprains, plantar fasciitis, Achilles tendinopathy, fifth metatarsal fractures, and anterior cruciate ligament ruptures. Data were analyzed using descriptive and correlational statistics.ResultsThe majority of players (85%) reported previous injuries, with ankle sprains (73.4%) and plantar fasciitis (35.1%) being most common. PNSQ-15 scores indicated high activation and concentration, with moderate confidence and motivation. Greater age and sport experience were associated with higher concentration and motivation. ABQ scores were moderate overall; more weekly training hours were associated with lower burnout in the dimensions of reduced sense of accomplishment and sport devaluation. Players with plantar fasciitis showed higher burnout scores, particularly in reduced sense of accomplishment (p=0.036).ConclusionFemale futsal players showed favorable psychological skills and moderate levels of burnout. Age, sport experience, and training load were associated with some psychological dimensions, while the presence of certain foot injuries was related to higher burnout scores. These findings suggest that psychological need satisfaction, training load, and injury history are interrelated factors influencing burnout and psychological well-being in female futsal players. Female futsal is growing rapidly, making it important to understand the psychological and physical factors that affect players’ well-being and performance. This study looked at how satisfaction of basic psychological needs such as feeling competent, connected, and autonomous relates to burnout, a state of emotional and physical exhaustion caused by prolonged stress. We also examined whether foot and ankle injuries influence burnout or psychological well-being. Ninety-four adult female futsal players completed questionnaires about their psychological skills, burnout levels, and previous injuries. Most players (85%) had experienced injuries, with ankle sprains and plantar fasciitis being the most common. Overall, players reported good psychological skills, especially in concentration and motivation. More experienced players showed better psychological outcomes. Players who trained more hours per week tended to have lower burnout, suggesting that regular engagement in sport can be protective. However, players with chronic foot injuries, like plantar fasciitis, showed higher burnout levels, indicating that persistent pain may negatively affect well-being. These findings highlight the importance of supporting both the psychological and physical health of female futsal players. Coaches and sports organizations should consider strategies that promote psychological skills, prevent injuries, and provide support for players dealing with chronic pain to maintain well-being and enhance performance.
To analyze the effects of 8-weeks of small-sided games (SSGs) training on the sprint force-velocity profile of youth football players, with special focus on potential baseline differences and training responses according to players' biological maturity status. Male football players (age: 13.9 ± 0.8years) were allocated to an experimental group (n = 49) or a control group (n = 30). The experimental group performed two SSGs sessions per week, integrated into regular team training, with progressive overload (e.g. intensity). Participants completed a maximal effort 30m linear sprint, from which sprint force-velocity variables were assessed, including theoretical maximal force (F0), maximal velocity (V0), maximal power (Pmax), maximal ratio of force application (RFmax), rate of decrease in force ratio (DRF), and maximal sprint velocity (Vmax). Players were stratified according to the predicted years from/to their peak height velocity (PHV): pre-PHV experimental (n=21), pre-PHV control (n = 15), post-PHV experimental (n = 28), and post-PHV control (n=15). A repeated measures ANOVA was performed to show group baseline differences as well as time and interaction effects. Post-PHV players displayed higher baseline values in all anthropometric (body mass, height) and sprint force-velocity variables compared with pre-PHV peers (p < .050). The F0, V0, Pmax, and Vmax improved after intervention compared to controls, independent from players PHV (no time×group interactions). Youth football players with advanced maturity status exhibited higher values in the sprint force-velocity variables compared to their peers with delayed maturity status before the intervention. However, the SSGs training program induced similar force-velocity profile gains for both maturity groups.
Background: Quantitative assessment of postural parameters in all anatomical planes may help clarify the potential role of posture in the pathomechanism of low back pain (LBP) in tennis players and support the development of preventive and rehabilitation strategies. This observational cross-sectional study aimed to compare selected pelvic and spinal posture parameters of amateur tennis players with LBP, amateur tennis players without LBP, and physically active controls without LBP who did not participate in asymmetric sports. Methods: The study included 116 participants (52 women and 64 men): amateur tennis players with self-reported tennis-limiting LBP within the previous 6 months, amateur tennis players without such a history, and physically active controls who did not participate in asymmetric sports and were free of LBP. Spinal and pelvic posture parameters were assessed using the DIERS Formetric 4D rasterstereography system. Group comparisons were performed using ANOVA or the Kruskal-Wallis test, as appropriate. Results: Across most analysed body posture parameters, no clear and consistent between-group differences were detected in this sample. Among men, significant between-group differences were observed in pelvic rotation and maximum right vertebral rotation. Men in the TBP (Tennis Back Pain) group showed a mean left-sided pelvic rotation compared with a mean right-sided rotation in those in the TNBP (Tennis No Back Pain) group, and lower maximum right vertebral rotation than men in the PAC (Physically Active Control) group. Among women, a significant between-group difference was observed for coronal imbalance, with higher left-sided values in the TBP group than in PACs. No consistent between-group differences were found across the remaining pelvic and spinal parameters. Conclusions: In this sample of amateur tennis players, static body posture parameters showed limited and non-uniform associations with LBP. The observed differences were selective and of uncertain clinical relevance, and the analyses did not reveal a single consistent postural pattern clearly associated with LBP in this sample.
Gosset, M, Coquart, A, Delaval, B, Catalano, J, Huou, G, Boufflers, M, Bozok, D, Bellanger, L, Douchet, T, Viroux, P, Jaffré, C, and Abaïdia, A-E. Compression garments and adaptations to plyometric training in soccer players: A randomized-controlled study. J Strength Cond Res XX(X): 000-000, 2026-The aim of this study was to analyze the effects of the chronic use of compression garments (CG) during a 6-week plyometric microcycle training block on training adaptations in soccer players. It was hypothesized that CG would have a beneficial effect on training adaptations, compared with placebo (PLA). Eighteen male soccer players (19.54 ± 1.39 years; 180.45 ± 5.25 cm; 71.14 ± 6.73 kg) from a reserve team of an elite professional club were randomly assigned to receive either CG or PLA for 24 hours after each plyometric session. The players participated in a plyometric training program: 2 sessions per week for 6 weeks. In a fully rested state, the players were tested before and after the training program on the following parameters: countermovement jump performance, One-leg sprint power, knee extensor strength, pennation angle of the calf muscles, creatine kinase levels, and perceived muscle soreness. The results were analyzed using a 2-factor mixed linear model. Countermovement jump performance showed a moderate, significant improvement in the CG group (d = 0.762), and a small, nonsignificant improvement in the PLA group (d = 0.344). One-leg power performance showed a large, significant improvement in the CG group (d = 1.690) and in the PLA group (d = 0.867). The results of this study show that the chronic use of CG for recovery does not negatively affect training adaptations and may improve power following a plyometric training program.
Iron deficiency (ID) can occur before anemia and may impair performance, recovery, and hematological function, particularly in athletes. Female basketball players may be especially vulnerable due to high training demands and sex-specific iron losses. Therefore, this study aimed to compare nutrient intake and hematological and iron status biomarkers between ID and non-ID female basketball players, and to examine diet-biomarker correlations. Twenty-four female basketball players completed the study. Athletes were stratified by ferritin, with ID defined as <30 μg/L, resulting in 12 athletes per group. Dietary intake was assessed using a 48 h food record. Energy, macronutrients, fiber, iron, calcium, folate, vitamin B12, and vitamin C intakes were analyzed. Blood biomarkers included red blood cells (RBCs), hemoglobin (HGB), hematocrit (HTC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), ferritin, serum iron, transferrin, total iron-binding capacity (TIBC), and unsaturated iron-binding capacity (UIBC). ID athletes had significantly lower fiber, iron, folate, and vitamin C intakes than non-ID. They also showed significantly lower HGB, HTC, MCV, MCH, and ferritin, and higher transferrin, UIBC and TIBC. Iron intake correlated positively with HGB, HTC, MCV, MCH, serum iron, and ferritin, and negatively with UIBC. Iron deficient female basketball players may present less favorable dietary profiles and altered hematological and iron status biomarkers. In this context, quarterly assessment of iron status biomarkers should be supported by nutrition education aimed at improving iron intake, alongside monitoring of energy and macronutrient intake in relation to training load. These approaches may help identify athletes requiring nutrition-focused support, although larger studies with longer-term dietary assessment are warranted.
Optimizing bone health is a key aspect of injury prevention both in the general population and in youth sports. Furthermore, the specifics of physical activity, along with nutrition, are potentially modifiable factors influencing the skeletal system. Assessing the relationship and further optimizing dietary intake and bone health is an important component of a comprehensive system of medical and biological monitoring of young athletes. The purpose of this study was to assess the incidence of decreased bone mineral density (BMD) and its relationship with dietary intake in young tennis players. The study involved 60 tennis players aged 7 to 17 years (33 female, 27 male). Dietary intake was assessed using 24-hour dietary recall for 3 survey days (2 training days and 1 day off) and food-frequency methods (for 1 month preceding the survey). BMD of the forearm and lower leg was assessed using ultrasound densitometry. The prevalence of reduced BMD (Z-score <-2.0 SD) in primary school-aged children was 37.5% for the radius and 20.8% for the tibia. Among children aged 11-14 years, low BMD of the radius was observed in 23.5% of those examined, and of the tibia in 11.8%, while in the older age group, only one of the 8 athletes had low BMD of both areas examined. One of the positive factors influencing bone tissue could be the effect of tennis-specific impact loading, which becomes apparent with increasing skill. Dietary imbalance consist of carbohydrate deficiency, which is most pronounced when calculated per kg of body weight in young men aged 15-17 years, girls aged 11-14 and 15-17 years, among whom not a single athlete had carbohydrate consumption reaching the lower limit of the recommended intake range. A surplus of dietary fat was observed regardless of age and gender, with a maximum intake of 3.8 g/kg body weight per day. A specific energy deficit was observed in girls aged 11-14 and 15-17. A positive correlation was noted between daily calories from protein and Z-score in the radius area of boys aged 7-10 years. A negative correlation was found in the group of senior school-age boys between fat intake in absolute and specific units and the BMD of the radius. Based on the study of the frequency of low BMD and its correlation with dietary intake, individual recommendations for adjusting the diet of young tennis players have been developed. X-ray osteodensitometry is recommended for athletes at risk. A comprehensive analysis of nutrition and physical development indicators allows for the timely identification of risks and the development of recommendations for optimizing the level of physical activity and diet of young tennis players to improve bone health.
The study compared the effects of three different heat stress conditions on the psycho-physiological responses and locomotor demands of young players in different small-sided soccer games (SSGs). Sixteen soccer players (age: 16.5 ± 0.5 years) performed 2-a-side and 4-a-side SSGs under three environmental heat stress conditions: low environmental heat (LEH) ≤ 23.9°C, moderate environmental heat (MEH) 24.0-27.9°C, and high environmental heat (HEH) 28.0-32.9°C. Players' heart rate (HR) responses and total distance covered (TDC) were continuously monitored for all SSGs; the rating of perceived exertion (RPE) and visual analog scale (VAS) were used after each bout. Tympanic temperature (TT) was recorded daily before and after the SSGs. The results demonstrated that for both 2-a-side and 4-a-side SSGs, significant main effects of temperature were observed for HR, %HRmax, RPE, and VAS responses (all p < 0.05), indicating progressively increased cardiovascular strain and perceptual load under higher heat stress conditions. In contrast, no significant main effects of temperature were found for TDC and TT responses in either game format. Interaction analyses revealed significant temperature × bout effects for most psychophysiological variables in both SSG formats, including HR, %HRmax, RPE, and VAS responses (all p < 0.05), suggesting that responses to heat stress varied across repeated bouts. However, no significant interaction effects were observed for TDC or TT in the 4-a-side SSGs, while only limited interaction effects emerged for TDC in the 2-a-side SSGs format. Overall, the findings indicate that heat stress substantially amplifies cardiovascular and perceptual responses during SSGs, with effects modulated by game format and bout structure. In contrast, TDC and TT appear less sensitive to these conditions. Coaches may use this evidence to manage players' internal and external load and optimize their team's performance across various heat-stress conditions.
Background: Trunk and pelvic strength balance and functional movement quality are relevant factors for musculoskeletal health and injury-prevention monitoring in youth soccer players. Aim: This study aimed to evaluate longitudinal changes in isometric trunk and pelvic strength balance, functional movement quality, and selected muscle imbalance indicators during a physiotherapy-based strengthening programme in adolescent male soccer players. Methods: A longitudinal single-group repeated-measures study was conducted in male soccer players aged 12-18 years. Isometric strength balance was assessed using the Dr. Wolff Back-Check system, and functional movement quality was evaluated using the Functional Movement Screen (FMS). Complete-case analyses were performed according to available repeated measurements. Results: FMS total scores improved across repeated assessments, whereas the global Back-Check score showed no significant longitudinal change. Component-level and imbalance analyses indicated reductions in adductor-abductor imbalance, and better FMS performance was moderately associated with lower adductor-abductor imbalance. Conclusions: Functional movement quality and selected muscle imbalance indicators demonstrated favorable longitudinal changes during the physiotherapy-based strengthening programme. These findings suggest that physiotherapy-oriented strengthening and movement-control exercises may contribute to improvements in functional movement quality and selected muscle balance indicators in adolescent male soccer players. However, the small repeated-measures subsamples and observational study design limit causal interpretation and generalizability.
Football is a complex team sport with high physical, tactical and technical demands, exposing players to a high risk of both contact and non-contact injuries. To map the range of preventative strategies used to reduce non-contact lower limb injuries among male footballers. Our study was conducted as a scoping review. The review was guided in five stages: (1) defining the research question; (2) identifying relevant studies; (3) selecting the topic; (4) charting and collecting data; and (5) summarising and reporting the results. The research was guided by the population, concept, context framework, focusing on professional and amateur male soccer players across various age groups. It examined a range of preventative strategies targeting non-contact lower limb injuries, recognising their critical role in reducing player exclusion because of injury. The literature search was conducted across eight electronic databases: PUBMED, CINAHL, PEDro, EBSCOhost, Cochrane Library, SPORTDiscus, Scopus and ScienceDirect. Twenty-five (out of 617) studies met the inclusion criteria, and their outcomes have been presented. Outcomes revealed various injury inhibition programmes implemented for non-contact lower limb injuries among male footballers, which were: Nordic hamstring exercises, Copenhagen adduction exercise, muscle strengthening, stretching exercises, ankle taping, FIFA 11, FIFA 11+ warm-up programme, preseason preparation, running mechanics, high chronic training loads, bounding exercises and a multicomponent exercise programme. The study identified a range of preventative strategies commonly employed to reduce the risk of non-contact lower limb injuries among male football players. Considering the varying dynamics across teams and competitive levels, these strategies can serve as a valuable framework for developing injury prevention programmes.
Low back pain (LBP) is common among adolescent racket sport athletes; however, simultaneous assessment of multiple sport-specific physical factors remains limited. This study aimed to identify physical factors associated with LBP in male high school soft tennis players with national-level competitive experience using a machine learning approach. Cross-sectional study. Preseason intensive training camps conducted at a single standardized training center in Japan, with participants recruited from elite teams across multiple regions. One-hundred and sixty male high school soft tennis players. LBP history was assessed using a self-administered questionnaire. Candidate variables included shoulder and hip rotational range-of-motion (ROM) indices and training-related factors. Feature selection was performed within a nested cross-validation framework. Six machine learning algorithms were evaluated using stratified five-fold nested cross-validation. Model performance was assessed using accuracy and area under the receiver operating characteristic curve (AUC), and feature importance was quantified using permutation importance. Logistic regression showed the most stable performance (mean AUC = 0.81). Across models, nondominant hip internal rotation ROM was consistently the most important feature. Restricted nondominant hip internal rotation ROM was consistently identified as the factor most strongly associated with LBP across models. This may represent a key physical characteristic associated with LBP in male high school soft tennis players.
Basketball requires repeated high-intensity actions such as sprinting, jumping, and change-of-direction (COD) movements. Therefore, repeated sprint training incorporating COD actions may be an effective strategy to improve basketball-specific physical performance. This study aimed to investigate the effects of a 6-week COD repeated sprint training program on explosive power, sprint performance, and COD performance in U19 basketball players. Twenty male U19 basketball players were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). The experimental group performed COD repeated sprint training three times per week for six weeks in addition to regular basketball training, while the control group continued regular training only. Performance assessments included countermovement jump (CMJ), squat jump (SJ), 30-m sprint, and T-test measures before and after the intervention. The experimental group demonstrated significant within-group improvements in CMJ, SJ, 30-m sprint, and T-test performance following the intervention. Between-group comparisons revealed significant improvements in CMJ and SJ performance in favor of the experimental group, whereas no significant between-group differences were observed for 30-m sprint or COD performance. A 6-week COD repeated sprint training program may be effective for improving lower-limb explosive power in U19 basketball players. However, its effects on sprint and COD performance appear limited when compared with regular basketball training. ClinicalTrials.gov Identifier: NCT07477379. Registered on 10.03.2026. Retrospectively registered.
Integrating proprioceptive and neuromuscular exercises into the FIFA 11+  Kids program may enhance motor performance and postural stability in youth athletes. This study aimed to determine the effects of a 12-week combined FIFA 11+  Kids and proprioceptive-neuromuscular training program (three sessions/wk) compared with regular standard soccer training on physical and postural performance in young male soccer players aged 12-13 years. Forty players (aged 12.19±0.59 years) were randomly assigned to an experimental group (n=20) or control group (n=20). Pre- and post-tests included anthropometry, linear sprints (5-10-20 m), vertical jumps (countermovement jump and squat jump), agility, Y-Balance, and stabilometric assessment (eyes open/closed). In the experimental group, body fat showed a non-significant downward trend (-2.93%; p=0.081), while leg muscle volume significantly increased (+5.53%; group×time: p=0.007; η p 2=0.183) alongside fat-free-mass (+2.41%; p=0.015). Sprint performance improved significantly at 5 m (5.16%; p=0.004; η p 2=0.206), 10 m (4.75%; p=0.008; η p 2=0.270), and 20 m (3.28%; p=0.019). Countermovement jump and squat jump also improved (7.63-14.97%; p=0.046 and p=0.002, respectively). Y-Balance scores and postural stability improved, particularly unipodal mediolateral sway (-35.19%; p=0.001; η p 2=0.224). Conversely, the control group showed no significant changes across anthropometric, performance, balance, or stabilometric parameters. The combined program effectively enhanced athletic performance, body composition, and postural control, strongly supporting its systematic implementation within youth soccer training programs.
Background: Rugby sevens has developed rapidly in China, but research on its related injuries remains limited; thus, clarifying injury characteristics is crucial for targeted prevention. Objective: The aim of this study is to investigate the distribution and incidence of training-related rugby sevens injuries by age and gender. Methods: A cross-sectional retrospective study was conducted using a self-reported questionnaire, recruiting 414 competitive rugby sevens players (aged 14-24 years) who participated in competitions at the city level or higher. Injuries were defined as rugby-related physical discomfort with training time loss, or medical care regardless of time loss. Injury rates were calculated via the Poisson distribution as standardized incidence per 1000 training hours. Results: Among 414 participants, 141 reported 283 injuries, with an overall rate of 0.80/1000 h (95% CI: 0.71-0.90), and the ankle (20.1%) and knee (18.7%) were the most common sites. The participants > 18 years had a higher injury rate (1.21/1000 h, 95% CI: 1.03-1.38) than those ≤18 years (0.52/1000 h, 95% CI: 0.42-0.62). Females (1.00/1000 h, 95% CI: 0.82-1.19) had a significantly higher rate than males (0.70/1000 h, 95% CI: 0.60-0.81), with females > 18 years having the highest rate (1.41/1000 h, 95% CI: 1.12-1.71). Conclusions: Lower-limb injuries (ankle, knee) are most common in 14-24-year-old elite players. Participants > 18 years and females have higher injury risks, providing epidemiological data for age- and gender-specific prevention.
Background: Nutritional supplementation is widely used to support physical and cognitive performance in football. However, evidence on multi-ingredient protocols combining taurine, caffeine, and phosphatidylserine (PS) remains limited in professional athletes. Methods: Eighty-one professional male football players (19-32 years) were randomly assigned to three groups (n = 27): placebo (P), taurine + caffeine (TC; 1500 mg taurine + 200 mg caffeine), and taurine + caffeine + PS (TCP; 1500 mg taurine + 150 mg caffeine + 300 mg PS) in a randomized, placebo-controlled, single-blind trial. Supplementation lasted 10 days, with a final dose administered 60 min before a standardized 105 min training session. Reaction time, sprint performance, GPS-derived variables, and technical/tactical indicators were assessed. Data were analyzed using ANOVA with post hoc tests, and pairwise comparisons were additionally adjusted using the Holm-Bonferroni correction due to the exploratory nature of the analysis. Results: Compared with placebo, the TCP group was associated with more favorable physical, cognitive, and selected game-related outcomes (p < 0.05). TCP was associated with higher locomotor performance (η2 = 0.13-0.20) and smaller fatigue-related declines in sprint performance (-18% vs. -34%) and speed (-10% vs. -19%) (η2 = 0.18-0.22). Reaction time and technical indicators, including passing accuracy (84% vs. 75%) and dribbling success (73% vs. 62%), were also improved. Higher coach-rated tactical performance scores were observed in TCP (η2 = 0.19-0.25). Conclusions: A short-term multi-ingredient protocol including taurine, caffeine, and PS may be associated with improved physical, cognitive, and selected game-related outcomes in professional football players. However, due to differences in caffeine dosage between groups, the independent effect of PS cannot be determined. Further double-blind studies are warranted. Given the exploratory nature of the analysis, the multiple assessed outcomes, and the partly subjective coach-rated tactical evaluations, the cognitive and tactical findings should be interpreted cautiously and regarded as preliminary rather than confirmatory evidence.
This study provides a comparative kinematic analysis of futsal instep shot performance between trained athletes and novice players, addressing limited evidence on how multijoint kinematic patterns are associated with ball velocity. Twenty trained futsal athletes and twenty novice players performed standardized instep shots recorded using high-speed cameras at 240 fps. Research procedures included camera calibration, frame-by-frame motion analysis, reliability testing, and kinematic extraction using Dartfish software. Joint angles, angular velocities, torso orientation, and ball velocity were examined using independent-sample t-tests, effect sizes, and multiple regression analysis. Trained athletes exhibited more optimized multijoint kinematic patterns, characterized by more mechanically efficient knee positioning during foot placement and backswing, improved torso stability, and effective upper-limb positioning. Significant between-group differences were detected across most kinematic variables (p < 0.05). Knee angular velocity emerged as the strongest predictor of ball velocity (R² = 0.62, p < 0.01). Optimized lower- and upper-body kinematic patterns are associated with shooting proficiency and performance, supporting targeted technical training focused on optimizing shooting mechanics and kinematic efficiency.
This study examined long-term neuromuscular and multidirectional speed development in elite youth badminton players and evaluated whether developmental stage influences adaptation trajectories during systematic training. Thirty athletes were monitored over 16 months with repeated assessments at five time points and stratified into Younger (8-14 years) and Older (15-22 years) developmental groups. A comprehensive test battery assessed explosive strength, reactive strength, musculotendinous stiffness, and badminton-specific multidirectional speed. Data acquisition was performed using a multi-sensor approach, including force-platform-based jump analysis, accelerometry-based systems, and electronic timing gates, enabling the objective, high-resolution, and repeatable monitoring of neuromuscular performance. Significant time effects were observed across all sensor-derived performance variables (p < 0.001), indicating robust improvements in speed, power, and neuromuscular efficiency. Adaptation trajectories were predominantly linear, with no evidence of performance plateauing. Although older athletes maintained higher absolute performance levels, Time × Group interactions were largely absent, demonstrating parallel improvement rates across developmental stages rather than a catch-up effect in younger players. Linear mixed models confirmed equivalent improvement slopes despite baseline differences, and adjustment for body mass attenuated but did not eliminate age-group differences in jump performance. Exploratory analyses revealed substantial inter-individual variability, identifying responder phenotypes independent of age. These findings indicate that systematically progressed training supports sustained, linear neuromuscular adaptation across youth badminton development and highlight the importance of long-term, individualized monitoring over age-based expectations of accelerated responsiveness.
This study investigated the impact of mental fatigue on lower limb biomechanics and bilateral asymmetry during drop landings in elite collegiate American football players to assess injury risk implications. Twelve elite male players performed bilateral drop landings before and after a 45-minute Stroop task. Data were analyzed using a 2 × 2 repeated-measures ANOVA. Irrespective of mental fatigue, the dominant limb exhibited significantly smaller hip flexion, larger peak vertical ground reaction force, and longer time to vertical ground reaction force peak compared to the non-dominant limb. Following mental fatigue, knee flexion range of motion and peak vertical ground reaction force increased bilaterally, and the non-dominant limb specifically demonstrated greater knee varus/valgus range of motion compared to baseline. While the symmetry index indicated baseline asymmetry, mental fatigue exerted no significant effect on global symmetry index. We conclude that mental fatigue impairs landing mechanics through limb-specific constraints rather than systemic symmetry collapse. Because localized compensatory mechanisms can preserve the overall symmetry index, relying solely on global symmetry metrics may mask underlying, joint-specific injury risks under mental fatigue. Consequently, athletic screening should prioritize the sensorimotor resilience of the non-dominant limb.
Neck pain is common in contact sports such as football, where rapid and accurate cervical range of motion (ROM) assessment is essential. Electronic goniometers provide reliable measurements but are impractical in field settings, leading clinicians to rely on visual estimation. The accuracy of this method and its improvement with repeated exposure remain unclear. To evaluate the agreement (trueness) between subjective visual assessments of active cervical range of motion and measurements obtained using an electronic goniometer, and to determine whether repeated assessments improve agreement over time. A three-time-point cohort study was conducted between August and December 2023 in male varsity-level American football players. At each time point, participants completed questionnaires on neck pain and disability and performed active cervical ROM (flexion, extension, side bending, rotation) assessed both subjectively and objectively. Agreement between subjective and objective evaluations was generally poor to moderate, with flexion and extension showing the lowest concordance. Repeated-measures ANOVA, assessing improvement due to exposition revealed no significant changes for flexion, extension, or rotations (p > 0.05). Significant improvements occurred for right side bending (p = 0.004) and left side bending (p < 0.001), with preseason-to-postseason differences of -0.44° and -1.64°, respectively, suggesting a limited learning effect for lateral movements. Subjective cervical ROM assessment varies by movement plane. Although repeated exposure improves trueness, subjective measures should be interpreted cautiously, and objective tools remain preferable for precise evaluation.
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Carpels, T, Kelly, S, and Kemi, OJ. Substitutions in professional elite soccer increase distance and high-intensity actions. J Strength Cond Res XX(X): 000-000, 2026-Physical performance in intense domains including distance covered and high-intensity actions are central for success in soccer. During a match, players need to appropriately distribute their capacity for intense match-play to last the full match. Substitutions may mitigate performance losses. Here, we investigated physical performance by global positioning system-tracked total distance, repeated high-intensity efforts and peak metabolic power, and result score impact, of substitutions in top division male professional elite soccer players (n = 48) in 95 competitive matches over 3 seasons, featuring 253 substitutions. We found that full match-players showed 4% higher maximal oxygen uptake (p < 0.05) versus substitution players. Relative distance covered in match was 50-74% higher (p < 0.01) in players who substituted into the match versus players who played the full match or were replaced during the match. Repeated high-intensity efforts in match was 61-93% higher (p < 0.01) in players who substituted into the match versus those who played the full match or were replaced during the match. These effects occurred in all player positions, and no home and away match differences occurred. Peak metabolic power did not differ between full-match or substitute players. Finally, we found that substitutions were 3-4 times more likely to improve match score than worsen it (p < 0.01), especially substitutions between 60 and 80 minutes of the match. In conclusion, substitutions permit a team to maintain or increase physical performance, including high-intensity actions, during the course of a match.