The objective of the study was to examine the effects of the relative age effect (RAE) and predicted maturity status on body size and repeated sprint ability (RSA: 7 x 34.2 m / 25 s interval) in youth soccer. The sample was composed of 197 male players aged 13-14 years. Body mass, stature, and sitting height were measured, RSA was assessed in the field, and age at peak height velocity (APHV) was predicted. Factorial ANOVA tested the independent and combined effects of RAE given by birth quarters (BQs) and maturity status on dependent variables. Players born in the second birth quarter (BQ2) were significantly taller (F = 4.28, p < 0.01) than their peers born in BQ1 and BQ3. Additionally, players born in BQ2 performed better than players born in BQ4 in RSA total time and ideal time (F ranged between 4.81 and 4.90, p < 0.01), while players born in BQ1 exhibited a lower RSA fatigue index compared to those born in BQ4 (F = 2.90, p < 0.05). The interaction of the BQ and maturity status was a significant source of inter-individual variation for body size (F ranged between 64.92 and 105.57; p < 0.01) and RSA output (F ranged between 4.082 and 6.76; p < 0.05). In summary, being relatively older and, simultaneously, advanced in maturity status corresponds to a substantial advantage in characteristics that are related to soccer-specific fitness.

The purpose of this study was to examine the effects of age and maturity on anthropometric and various fitness characteristics in young competitive female tennis players. Sixty-one players, aged 10.4–13.2 years (11.8 ± 0.8) were measured for standing and sitting heights, body mass, skinfolds, grip strength, and agility, and dichotomized into two age (U12 and U14) and maturity (earliest and latest) groups according to their chronological age and maturity status. The results revealed significant age effects for stature, sitting height, leg length, and hand grip in favor of the older players. Girls contrasting in maturation differed significantly for all anthropometric and physical performance variables except for body mass index (BMI), body fat percentage (BF%), and hexagon agility test. The earliest maturing group showed significantly higher values for anthropometric measures and better results in the hand grip test than the latest maturing group. After controlling for chronological age, differences were revealed between contrasting maturity groups in stature, sitting height, BF%, and the hand grip test. The findings highlight the age- and maturity-related trends in body size and muscular strength among young female tennis players in the pubertal period. Nevertheless, the differences in the body composition and agility of the contrasting age and maturity groups were negligible.

Sport for children and adolescents must consider growth and maturation to ensure suitable training and competition, and anthropometric variables could be used as bio-banding strategies in youth sport. This investigation aimed to analyze the association between chronological age, biologic maturation, and anthropometric characteristics to explain physical performance of young judo athletes. Sixty-seven judokas (11.0–14.7 years) were assessed for anthropometric and physical performance. Predicted adult stature was used as a somatic maturation indicator. A Pearson’s bivariate correlation was performed to define which anthropometric variables were associated with each physical test. A multiple linear hierarchical regression was conducted to verify the effects of age, maturity, and anthropometry on physical performance. The regression models were built with age, predicted adult stature, and the three most significantly correlated anthropometric variables for each physical test. Older judokas performed better in most of the physical tests. However, maturation attenuated the age effect in most variables and significantly affected upper body and handgrip strength. Anthropometric variables attenuated age and maturity and those associated with body composition significantly affected the performance in most tests, suggesting a potential as bio-banding strategies. Future studies should investigate the role of anthropometric variables on the maturity effect in young judokas.

Sex differences and maturation-associated variation in fitness and motor coordination were examined in children aged 8–9 years (n = 128, 67 girls). Assessments included stature and body mass, two-component body composition, percentage of predicted adult stature (as an index of biological maturation), and motor performance and coordination (Körperkoordinationstest für Kinder). Compared to girls, boys were less advanced in maturation status, possessed larger fat mass, demonstrated superior performances in six tests of fitness, and obtained one superior score on the Körperkoordinationstest für Kinder. After controlling for somatic maturation, sex differences persisted in the two multivariate domains: motor performance and motor coordination.

Young judo athletes are bio-banding based on age and body mass and compete in weight classes. The purposes of this study were to investigate the influences of maturation on physical performance in young judokas through controlling the chronological age and body mass, and to examine the mediating role of anthropometric variables. Sixty-seven judokas, aged 11.0–14.7, were measured for 11 anthropometric and seven physical performance variables. Pearson partial correlations were conducted to verify the relationship between the maturational indicator and the dependent variables. Mediation analyses were performed to identify the extent to which anthropometric variables mediate the relationship. The maturation effect remained on the aerobic capacity and handgrip strength (p < 0.05). Fat mass (b = 80.335, 95%CI 11.580–204.270) and fat-free mass (b = 108.256, 95%CI 39.508–207.606) totally mediated the effect on aerobic capacity. Fat mass (b = 0.023, 95%CI 0.004–0.057), fat-free mass (b = 0.029, 95%CI 0.011–0.058), stature (b = 0.031, 95%CI 0.008–0.061), arm span (b = 0.021, 95%CI 0.003–0.044), and inferior members length (b = 0.022, 95%CI 0.005–0.049) totally mediated the effect on handgrip strength. The effect of biological maturation is noticeable even after age and body mass control, being mediated by anthropometric variables related to body composition and size.

This study aimed to predict motor coordination from a matrix of biocultural factors for 173 children (89 boys, 84 girls) aged 7–9 years who were assessed with the Körperkoordinationtest für Kinder test battery. Socioeconomic variables included built environment, area of residence, mother’s educational level, and mother’s physical activity level (using the International Physical Activity Questionnaire [short version]). The behavioral domain was marked by participation in organized sports and habitual physical activity measured by accelerometers ( ActiGraph GT1M ). Indicators of biological development included somatic maturation and body mass index. Among males, the best logistic regression model to explain motor coordination (Nagelkerke R ² = 50.8; χ ² = 41.166; p < .001) emerged from age-group (odds ratio [OR]: 0.007–0.065), late maturation (OR = 0.174), normal body weight status (OR = 0.116), mother’s educational level (OR = 0.129), and urban area of residence (OR = 0.236). Among girls, the best logistic regression to explain motor coordination (Nagelkerke R ² = 40.8; χ ² = 29.933; p < .01) derived from age (OR: 0.091–0.384), normal body mass index (OR = 0.142), participation in organized sport (OR = 0.121), and mother’s physical activity level (OR = 0.183). This sex-specific, ecological approach to motor coordination proficiency may help promote physical activity during prepubertal years through familiar determinants.