Search Results (827)

Tracking biomechanical changes associated with different training modalities remains a methodological challenge in applied sports science. This pilot longitudinal study examined stroke technique stability in seven junior rowers (aged 16.6 ± 0.5 years) across three measurement sessions (March, April, June), separated by two training mesocycles emphasising strength training and intensive rowing, respectively. Upper body angular velocity was recorded using a smartphone-based MEMS sensor fixed to the upper back during incremental ergometer exercise. Overall stroke duration and its standard deviation remained stable throughout the study period, whereas the durations of the two stroke phases corresponding to forward (drive) and backward (recovery) body motion changed systematically across mesocycles. Phase-specific changes were statistically significant in 10 of 12 paired comparisons (rank-sum test) and 7 of 12 within-subject comparisons (Wilcoxon signed-rank test) for phase durations, and in 9 and 5 of 12 comparisons for their standard deviations, respectively. These findings suggest that the internal structure of the rowing stroke is sensitive to training load specificity, even when overall stroke timing remains unchanged, and that smartphone-based angular velocity analysis provides a feasible tool for individualized biomechanical monitoring in young athletes. Full article

Background/Objectives: Mind–muscle connection (MMC) refers to a strategy in which an individual intentionally focuses attention on specific muscles to enhance the neural activation of those muscles. The purpose of this study was to examine the acute effects of MMC directed toward a specific muscle during a machine-based shoulder press exercise on the muscle activity of untrained individuals. Methods: Thirty-one healthy young adults with no athletic or resistance training experience participated in this single-session study. Participants performed machine-based shoulder presses at 40% of one-repetition maximum intensity under three MMC conditions. The three conditions were: no-focus condition, deltoid (DT)-focused condition, and triceps brachii (TB)-focused condition. Muscle activities of the DT, TB, and upper trapezius (UT) were measured during exercise under each MMC condition. Differences in muscle activity across conditions were analyzed using a two-way repeated-measures analysis of variance. Results: A total of 31 participants were included in the final analysis. A significant interaction between muscle and MMC condition was observed (p < 0.001). Post hoc analysis showed that DT activity was higher in the DT-focused condition, whereas TB activity was higher in the TB-focused condition (p < 0.001). UT activity did not differ across conditions (p > 0.05). Conclusions: MMC selectively enhanced target muscle activity without changing non-target muscle activity, indicating its potential for selective neuromuscular recruitment. These findings suggest that MMC may serve as a practical strategy for selective muscle activation during machine-based resistance training. Further study is needed to determine whether these findings translate into long-term improvements in muscle strength and functional performance. Full article

(1) Background: This study aims to investigate the differences in body composition, muscle strength, and power between young karate athletes from different competitive disciplines. (2) Methods: The study sample consisted of 131 participants (69 boys and 62 girls) aged 10–14 years divided into three groups: kata (n = 48), kumite (n = 40), and athletes competing in both disciplines (n = 43). The set of variables included 1 anthropometric variable, 6 variables for assessing body composition (InBody 270), 8 variables for assessing handgrip strength (handgrip strength test, Fmax, RFD, absolute and relative, both hands), and 3 variables for assessing lower limb muscle power (force plate, CMJ height and power). Of the statistic analysis, MANOVA and ANOVA, along with MANCOVA and ANCOVA were performed. (3) Results: The adjusted results revealed significant general differences between groups (from p = 0.005 to p = 0.009). Regarding body composition, kumite athletes are taller, have greater body mass, body water, proteins, minerals, and muscle mass content than kata athletes and athletes specialized in both disciplines (from p = 0.002 to p = 0.045). The young karate athletes specialized in kumite competition exhibit higher levels of absolute handgrip muscle strength, rate of force development, and absolute lower limb muscle power than kata athletes and athletes specialized in both disciplines (from p = 0.002 to p = 0.041). There were no significant differences in any measured parameters between kata athletes and young karate athletes specialised in both disciplines. (4) Conclusions: The results are associated with higher values of body composition, muscle strength, and power in kumite athletes compared to kata athletes and athletes competing in both disciplines. Full article

Perceptual–cognitive abilities are essential components of performance in volleyball, where players must quickly interpret visual information and respond effectively to rapidly changing game situations. The present study aimed to examine perceptual–cognitive abilities and reaction performance in competitive female volleyball players and to explore how these abilities may contribute to athlete development and training design. Thirty-nine young female volleyball athletes participated in the study and underwent an evaluation of perceptual–cognitive abilities considered critical for volleyball performance. These abilities were assessed through specially designed computer-based tasks delivered via dedicated experimental software, enabling the measurement of reaction time and response accuracy during perceptual–motor processing. Group comparisons did not reveal significant differences between playing positions or competitive levels in the measured perceptual–cognitive abilities. Multivariate and clustering analyses suggested the presence of potential performance patterns characterized by different combinations of reaction speed, response accuracy, and perceptual–cognitive processing. However, these patterns should be interpreted with caution, as the clustering solution showed limited separation (silhouette score = 0.02), indicating an exploratory and non-definitive structure. Overall, the findings highlight the multidimensional nature of perceptual–cognitive performance in volleyball and suggest that athletes may rely on different perceptual–motor strategies when responding to game-related stimuli. From an applied perspective, integrating perceptual–cognitive challenges into training environments may support athlete development and improve decision-making efficiency in dynamic game situations. Full article

Background: Anterior cruciate ligament (ACL) injuries in youth athletes are multifactorial, and the relative contributions of neuromuscular and neurocognitive variables remain inadequately comprehended. Methods: In this prospective cohort study, 220 young handball players (104 girls and 116 boys; mean age 16.3 ± 1.4 years) participated in functional testing with the Back in Action system and baseline neurocognitive evaluation with the ImPACT battery. During the 24-month follow-up period, orthopedic specialists identified ACL damage, which was confirmed by magnetic resonance imaging (MRI). Univariable logistic regression and receiver operating characteristic (ROC) curve analyses were conducted to evaluate predictive capability. Results: During the 24-month follow-up, 26 athletes sustained an ACL injury. Prolonged plyometric ground contact time was significantly associated with ACL injury occurrence in logistic regression analysis (p = 0.019) and demonstrated fair discriminatory ability (AUC = 0.63) (OR = 0.98 per ms; 0.98 95% CI: 0.964–0.997). Female sex emerged as a profound and independent risk factor (OR = 5.74). Conclusions: Neuromuscular performance, specifically plyometric ground contact time and female sex, has predictive ability for ACL damage in youth handball players, while separate cognition assessments failed to independently differentiate injury risk. These findings support the use of objective neuromuscular evaluation in comprehensive injury prevention strategies in youth sport. Full article

Objective: To analyze the relationship between weekly accumulated external load and pre-match neuromuscular performance assessed through the countermovement jump (CMJ), in under-21 (U21) football players across 10 competitive microcycles. Methods: Sixteen U21 football players (age: 18.9 ± 0.42 years; height: 180 ± 6.3 cm; body mass: 78.5 ± 8.5 kg) from a Chilean professional club were monitored over 10 consecutive weeks. In each microcycle, the relationship between changes in neuromuscular performance estimated from CMJ-derived variables and two components of external load was analyzed: (1) weekly accumulated external load and (2) the acute–chronic workload ratio (ACWR). External load variables included total distance (TD), high-speed running distance (HSR), accelerations (ACC), decelerations (DC), and PlayerLoad (PL). CMJ variables included jump height (JH), modified reactive strength index (RSI-mod), and peak eccentric velocity (PEV). Performance changes were calculated as the percentage change (Δ%) between MD + 2 (start of the microcycle) and MD − 1 (pre-match). Pearson or Spearman correlation coefficients were applied depending on data distribution. Results: Significant negative associations were observed between weekly accumulated external load and changes in CMJ performance. Reductions in JH were associated with TD, HSR, ACC, and PL. Similar patterns were found for RSI-mod, while PEV showed a particularly strong association with ACC. Additionally, ACWR demonstrated significant negative relationships with CMJ changes, especially for HSR, ACC, and PL. Conclusions: Higher weekly accumulated external loads and elevated ACWR, particularly in high-intensity metrics such as high-speed running and accelerations, are associated with impaired pre-match neuromuscular performance. Consequently, monitoring CMJ-derived variables alongside external load data is recommended to manage fatigue and optimize match readiness in young football players. Full article

Background: Anterior cruciate ligament (ACL) injuries are increasing in young athletes and many are related to non-contact, spontaneous mechanical fatigue-related ruptures. The objective of this narrative review is to identify and synthesize the anatomical, histological, physiological, and biomechanical basis of extracellular matrix (ECM) factors that contribute to ACL injuries and suggest ways to decrease their occurrence. Methods: The primary investigator searched PubMed, Web of Science, and Google Scholar database titles and abstracts using search phrases with Boolean operators: “anterior cruciate ligament” OR “ACL”, OR “cranial cruciate ligament” AND “disease”; “anterior cruciate ligament” OR “ACL”, OR “cranial cruciate ligament” AND “spontaneous rupture” OR “non-contact injury”; and “anterior cruciate ligament” OR ACL, OR cranial cruciate ligament” AND “crosslink”, “collagen” OR “extracellular matrix”; and “anterior cruciate ligament” OR “ACL”, OR “cranial cruciate ligament” AND “microtrauma”, OR “sudden” OR “fatigue failure”. The primary investigator and a sports orthopedic surgeon reviewed titles and abstracts of diverse evidence sources. From these identified sources, the study team performed full text reviews, selected contributing articles, performed Strength of Recommendation Taxonomy (SORT) grading, and synthesized the following themes: A Hostile Environment, ACL Strain, and Poor Nutrient Delivery; Accumulative ACL Microtrauma and Mechanical Failure; The ACL Differs From Other Ligaments; Collagen, the ECM, and ACL Mechanobiology; Crimps and ACL ECM Stretch; Crosslinks Improve ECM Mechanical Properties; The Delicate Collagen Synthesis and Degradation Balance; Exercise Training and the ACL; Can Nutraceuticals Help Restore the Balance?; Training Induced ACL Hypoxia; Estrogen and the Female Athlete; Counting Pitches or Counting Collagen Fiber Ruptures; and Restoring A Positive Anabolic–Catabolic Collagen Balance. Results: Regular exercise training within a physiologically safe loading range is vital to ACL ECM health. However, low or moderate evidence suggested that poor blood supply, slow metabolism, and a hypoxic environment may unbalance anabolic and catabolic homeostasis. Active rest and recovery concepts that prevent youth baseball shoulder and elbow injuries may help prevent non-contact ACL injuries. Conclusions: More prescriptive active rest and recovery intervals and neuromuscular control training may restore the anabolic–catabolic balance that increases mature crosslink density and improves ACL ECM strength. Confirmatory studies are needed to better establish therapeutic intervention mode(s), timing, dosage, and frequency optimization. Full article

Ventricular repolarization abnormalities are among the most frequent electrocardiographic findings in pediatric athletes undergoing cardiovascular screening, yet their clinical significance remains a major source of diagnostic uncertainty. While most of them represent benign expressions of training-induced cardiac remodeling and developmental maturation, selected patterns may constitute the earliest phenotypic manifestation of cardiomyopathies or primary electrical disease. Distinguishing physiological adaptation from early pathology is therefore essential to prevent both sudden cardiac events and unnecessary restrictions on sports participation. This review integrates contemporary international electrocardiographic interpretation criteria with emerging pediatric evidence to provide a clinically oriented framework for evaluation and risk stratification of ventricular repolarization abnormalities in pediatric athletes. Early repolarization and anterior T-wave inversion are commonly benign when occurring within recognized age- and ethnicity-specific patterns and in the absence of symptoms, concerning family history, or structural abnormalities. Conversely, lateral or inferolateral T-wave inversion, atypical ST-segment morphology, complex ventricular arrhythmias, and abnormal imaging findings represent red flags requiring comprehensive investigation, including multimodality imaging when indicated. Due to the dynamic electrophysiological evolution during adolescence, longitudinal reassessment is crucial. A structured, risk-based approach integrating electrocardiographic features, demographic/familial context, clinical evaluation, imaging findings, and follow-up provides a pragmatic strategy to optimize risk detection while safeguarding appropriate athletic participation in young athletes. Full article

Judo, as a weight-category combat sport, exposes young athletes to body mass pressures that may foster abnormal eating behaviours. Building on a companion study that documented the prevalence and sex-specific characteristics of abnormal eating behaviours in this cohort, this secondary analysis aimed to identify training-related predictors of eating behaviours in young Polish judo athletes, examine body image satisfaction as a mediator, and assess whether patterns observed in elite adult athletes apply to younger populations. The participants were 150 athletes (70 girls, 80 boys) aged 12–17. Eating behaviours were assessed using the Three-Factor Eating Questionnaire (TFEQ-13) and the Test of Eating Situation Style (TSJ); training characteristics, pre-competition weight control, and appearance satisfaction were examined through hierarchical regression, mediation analysis, latent profile analysis, and two-way ANOVA. Training-related factors—including tenure, session frequency, competitive level, and pre-competition weight control—showed no significant associations with eating behaviours. However, in a subsample of N = 136 athletes, relative weight grouping predicted dietary restraint (p = 0.015, η²p = 0.066), with athletes in the heaviest tertile reporting higher restriction; lower appearance satisfaction was associated with greater restraint (p = 0.031, β = −0.192), independently of sport-mandated weight control; females demonstrated higher emotional eating across instruments (p < 0.001). These findings suggest that body image and weight classification may be more strongly associated with eating behaviours than training demands, highlighting the need for body image interventions and the monitoring of athletes near weight category boundaries. Full article

In elite youth soccer, the objective is to identify, develop, and enhance players’ ability to support their progression. During adolescence, players of the same chronological age often show differences in technical, tactical, physical, and psychological performance due to variations in biological maturation. The bio-banding (BB) format tries to reduce these discrepancies by grouping players with maturity-matched peers, promoting development within a maturity-respecting environment. This review synthesizes the effects of BB on soccer-specific performance in comparison to traditional chronological-age (CA) grouping. PubMed, Scopus, Web of Science (Core and Medline), and BASE databases were searched, and experimental studies using crossover, such as those applying both BB and CA in young soccer players, were considered eligible. Eleven experimental studies were included. Most of the investigated outcomes focused on physical performance (n = 9) and technical and tactical characteristics (n = 8), while psychological aspects were less examined (n = 2). Moreover, two studies further assessed how different BB methods influenced the investigated outcomes. The evidence confirms that BB influences youth soccer player characteristics, showing differences compared to CA grouping. BB can be an approach for optimizing individual growth but is not a definitive solution, presenting limits that require careful management, appropriate challenge, and integration with injury prevention and workload monitoring. Further research is needed to clarify its performance-related impact across maturity statuses. Full article

Background: Race walking, an Olympic discipline, produces an increase in energy cost and a change in the recruitment pattern of muscle fibres compared with running, yet the cardiorespiratory responses of elite race walkers to severe-intensity exercise remain poorly characterised. Objectives: (i) To determine whether exhaustive exercise performed at vΔ50 elicits VO₂max in young elite race walkers, and (ii) to compare the temporal and metabolic profiles of this effort with those of similarly trained runners. Methods: Fourteen elite junior athletes (seven race walkers and seven runners) completed an incremental test to determine velocity at the lactate threshold (vLT), vVO2max, and VO2max, followed by a constant-velocity trial at individual vΔ50 performed to voluntary exhaustion on a 400 m track. Breath-by-breath VO2, heart rate, capillary blood lactate concentration, and time to exhaustion, time limit (Tlim) were measured. Results: At vΔ50 (≈94% vVO2max), the race walkers reached VO2max, with no detectable VO2 slow component (SC) in six of seven participants. In contrast, runners exhibited a significant SC (8 ± 3% of total VO2). The energy cost (EC) was 16% higher in race walking than in running (p < 0.01). Conclusions: In elite junior race walkers, it seems that vΔ50 reliably elicits VO2max primarily due to a high baseline oxygen cost rather than a progressive VO2 SC, contrasting with the kinetic response observed in running. These discipline-specific responses suggest that interval training in race walking should be prescribed using walking-specific thresholds. This study is preliminary, given the small sample size; further studies with larger cohorts are warranted. Full article

Background: Health-related behaviors often cluster during young adulthood, potentially increasing the risk of long-term adverse health outcomes. Understanding how lifestyle risk behaviors co-occur among university students is essential for developing targeted health promotion strategies. Objective: This study aimed to identify lifestyle risk profiles among university students based on the co-occurrence of smoking behavior, alcohol consumption, sedentary behavior, and body weight status. Methods: A cross-sectional study was conducted with 147 university students enrolled in a physical education and sport undergraduate program (mean age: 20.58 ± 2.94 years; 80.3% male). Physical activity and sedentary behavior were assessed using the International Physical Activity Questionnaire–Short Form (IPAQ-SF), while smoking and alcohol consumption were self-reported. Body mass index was used to classify weight status. Lifestyle risk profiles were identified using two-step cluster analysis based on regular smoking, alcohol consumption, sedentary behavior, and overweight/obesity. Differences in cluster distribution according to sex and federated athlete status were examined using chi-square tests. A two-step cluster analysis based on the Bayesian Information Criterion (BIC) and silhouette measure was used to identify lifestyle risk profiles. Results: Overall, 46.9% of participants had experimented with tobacco, 11.6% were current smokers, and 74.8% reported alcohol consumption. Participants accumulated an average of 3772.25 ± 1957.99 MET-min/week of physical activity. Three distinct lifestyle risk profiles were identified. Cluster 1 (46.9%), labeled the alcohol profile, was characterized by alcohol consumption without smoking and no prevalence of being overweight. Cluster 2 (20.4%), the multiple-risk profile, included participants who reported regular smoking, with nearly half presenting sedentary behavior and overweight/obesity. Cluster 3 (32.7%), the overweight profile, was characterized by overweight/obesity combined with alcohol consumption but no smoking. No significant differences were observed in the distribution of lifestyle profiles according to sex (p = 0.111) or federated athlete status (p = 0.087). Conclusions: Lifestyle risk behaviors cluster into distinct profiles among university students, with alcohol consumption appearing across multiple profiles and smoking concentrated in a specific high-risk group. These findings highlight the need for targeted health promotion strategies addressing multiple co-occurring behaviors within university populations. Full article

Objective: The purpose of this study was to compare the influence of biological maturity status and training experience on motor performance in young athletes of different sport disciplines. Methods: Youth athletes (n = 84, 23 females) from five different sports (basketball, volleyball, track and field, wrestling, and badminton) participated in this study. Jump height was measured for the squat jump (SJ) and countermovement jump (CMJ). Peak torque during maximal voluntary contractions (MVCs) and torque steadiness at 20% MVC were assessed during plantar flexion (PF) and dorsiflexion (DF). Postural control was assessed with the one-leg test for both the right and left legs. K-means clustered analysis categorized participants into groups of low and high performers. Results: High performers had greater training experience than low performers for the SJ (p < 0.05), with no difference in maturity status (p > 0.05). Similarly, high performers had greater training experience (p < 0.05) than low performers for the CMJ, with no difference in maturity status (p > 0.05). High performers were more mature than low performers for MVC torque of DF (p < 0.001) and PF (p < 0.001), with no group differences in training experience (DF: p > 0.05; PF: p > 0.05). Maturity status for torque steadiness differed only for DF (p < 0.001), whereas there was no difference for PF (p > 0.05). There were no differences in either maturity status or training experience for one-leg-stance time (p > 0.05). Conclusions: These findings suggest that maturity status and training experience are linked to performance, although their relative roles differ across tasks. These findings reflect an interaction between biological maturity, training background and sports performance in youth athletes. Full article

This study investigated interlimb asymmetries in lower limb performance using both vertical and horizontal jump tests in elite young basketball players. Specifically, it aimed to determine whether (1) unilateral jump performance and (2) the magnitude of interlimb asymmetry differed across maturity groups, whether (3) limb dominance influences performance, and whether (4) asymmetry direction is consistent across tests. One hundred elite male basketball players (U13 to U19) were categorised into three maturational stages: Pre-PHV (n = 19), Circa-PHV (n = 29), and Post-PHV (n = 52). Each athlete performed the following unilateral tests with both the dominant and non-dominant leg: single-leg hop, triple hop for distance, 6 m timed hop, single-leg countermovement jump (SL-CMJ), and single-leg drop jump (SL-DJ) from a 30 cm box. The Bilateral Strength Asymmetry (BSA) index was computed for each test. All tests showed significant differences between Pre-PHV and Circa-PHV groups (p < 0.001), whereas only the 6 m timed hop differed between Circa-PHV and Post-PHV (p < 0.01). BSA did not differ significantly across maturation stages in any test, except for the single-leg hop. Agreement in asymmetry direction between test pairs was slight to fair (kappa ≤ 0.29). BSA values remained largely stable across maturational stages, suggesting that interlimb asymmetries are established before PHV, likely during childhood. Limb dominance did not affect jump performance, and asymmetry direction varied between tests, confirming they are not interchangeable. Full article

Background: Gross movement skills (GMS) development is important for long-term physical activity participation. Despite this, the influence maturation has on GMS is understudied. The purpose of this pilot study was to evaluate the effect of maturation and sex on GMS in adolescents and identify numbers for a definitive study. Methods: We recruited seventy-one athletes (21 male, 50 female) from 8 to 17 years of age. Height, sitting height, and body mass were measured, and biological age (indexed as years from peak height velocity [PHV]) was predicted. Athletes were classified into three maturational categories: pre-PHV, peri-PHV, and post-PHV. The Test of Gross Motor Development-2 was used to assess GMS. Differences in overall GMS, locomotor skill, and object control skills were evaluated using ANCOVA controlling for height, weight, sex, physical activity, and sport specialization. Results: We found that GMS scores were greater for athletes post-PHV (83.62 ± 6.09) when compared to athletes peri-PHV (74.25 ± 12.92; p = 0.01). There were no differences between the pre-PHV and post-PHV groups (p = 0.13). Between sexes, males had greater GMS scores than females within each maturational category (p < 0.05). Conclusion: Our pilot study is inconclusive but suggests that factors such as sex, exposure to different GMS, and time spent practicing GMS may influence GMS performance to a greater extent than maturation. However, these findings are underpowered; a sample of 154 would be required for a definitive study. Full article