Developmental changes in the physical fitness of young female and male basketball players: a Bayesian analysis.

Background: This study examined the sex-related variation in the developmental changes of growth and physical fitness outputs in young Brazilian basketball players.

Methods: The study included repeated measures of 90 players (46 females and 44 males), aged between 9.5 and 19.5 years. Performance assessment included the countermovement jump, line-drill test, and yoyo intermittent recovery test level-1. With a mixed-longitudinal design, athletes were measured at least 2 times over 12 months and a maximum of 36 months. Bayesian hierarchical models were used to model developmental trends across adolescence.

Results: Our model-based predictions indicate substantial differences in the rate of development of both vertical jump and line-drill test performances and performance development leveling off. Female players' maximal short-term performance rate of development was lower, and a plateau in improvements was attained earlier than male players. There was substantial variation in the rate of development of intermittent endurance between females and males, which became clear when intermittent endurance development was adjusted for body size in the model, particularly for female players.

Conclusions: These findings offer valuable insights to youth basketball coaches when interpreting the asynchrony in growth and physical fitness progression during adolescence.