Modeling longitudinal changes of maximal short-term power outputs in young volleyball players: a Bayesian analysis

This study examined the sex-related variation in the developmental changes of maximal short-term power outputs in young Brazilian volleyball athletes while considering the potential influence of body size. The study included 75 participants, comprising 35 females and 40 males aged between 10.5 and 17.8 years. Performance assessment included the countermovement jump, 10 m sprint, 2 kg medicine ball throw and volleyball-specific agility. Athletes were measured 3–4 times over 12 months. Bayesian hierarchical models were used to model developmental trends across adolescence. The results revealed substantial developmental improvements in maximal short-term power outputs during adolescence, with particularly noteworthy advancements observed among male athletes. Our model predictions revealed a pronounced non-linear increase in jumping and sprint performance at around ages 14 and 16 years for females and males, respectively; however, further improvements plateaued once these peak levels were attained, resulting in negligible gains. Female athletes displayed a markedly lower rate of development in the 2 kg medicine ball throw compared to male athletes. Conversely, there were no sex-based differences in the rate of linear performance improvement in the volleyball-specific agility test. These findings offer valuable insights to coaches, helping them better comprehend the asynchrony in the progression of volleyball-specific maximal short-term power outputs during adolescence.