Maturity-Related Adaptations to Combined Traditional Resistance and Plyometric Training in Pre- and Post-Peak Height Velocity Boys

This study examined the effects of a 12-week training intervention on drop jump kinetics in pre- and post-peak height velocity (PHV) boys. Forty boys from a range of sports, aged 9-17 years, were categorized into two maturity groups (pre- and post-PHV) and subdivided to an experimental (EXP) or control (CON) group. The EXP groups completed twice weekly combined traditional resistance and plyometric training program, whereas the CON groups continued regular sports activities. Drop jump ability was quantified by examining performance variables (jump height, ground contact time, and reactive strength index [RSI]), absolute and relative kinetic variables (force, impulse, and power), and movement strategy variables (spring-like correlation, peak center of mass [COM] displacement, and COM velocity). Differences in all variables were analyzed using 2 × 2 × 2 (maturity × group × time) mixed-model ANOVA. Statistical significance was determined as p < 0.05. There were significant maturity × group × time interactions observed for jump height, RSI, mean and peak breaking force, relative breaking force, net impulse, and for all absolute and relative power variables. The results indicate that maturity status influences responsiveness to combined training in boys, with the post-PHV group showing greater adaptations in drop jump performance than their less mature peers. Practitioners aiming to develop stretch-shortening cycle function in post-PHV youth should program a combination of resistance training and plyometrics. Longer interventions with more focused exposure to plyometric training might be required to elicit more meaningful improvements in drop jump performance in pre-PHV children. [Abstract copyright: Copyright © 2025 National Strength and Conditioning Association.]