Do anthropometric characteristics and physical capacities of highly trained junior badminton players differ according to age and sex?

The aim of this study was to investigate differences in anthropometric characteristics and physical capacities between (i) under (U) 13, U15, and U17 highly trained junior badminton players and (ii) sexes within each age group. Sixty-two Indonesian highly trained junior badminton players were tested over two sessions for body height, weight, fat mass, and body mass index (BMI), as well as balance, reaction time, hand grip strength, counter movement jump height, linear and non-linear sprint times, and anaerobic sprint and multistage fitness test performances. Traditional (one-way ANOVA or Kruskal-Wallis tests) and alternative statistical approaches (magnitude-based inferences) as well as effect size (ES) calculations were applied for statistical analysis. Regarding age-related differences, in males, U17 players had a statistically significant and most likely higher BMI ( p = 0.001; ES = very large), as well as statistically significant and most likely superior CMJ height, linear sprint performance, fatigue index, and relative peak power than the U13 players ( p ≤ 0.003; ES = large to very large). In females, U17 players had a statistically significant and most likely higher BMI and body fat mass ( p ≤ 0.002; ES = large to very large), as well as statistically significant and very likely inferior non-linear sprint performance and relative peak power than the U13 players ( p ≤ 0.005; ES = large). For sex-related differences, in U17 and U15 players, males had a statistically significant and most likely lower body fat mass ( p = 0.001; ES = very large), as well as statistically significant and most likely superior linear sprint performance and relative peak power than females ( p = 0.001; ES = large to extremely large). Our study shows that anthropometric characteristics and anaerobic capacities differ by age and sex, whereas aerobic capacity is similar among Indonesian highly trained junior badminton players.