The Influence of Somatic Maturation on Stretch-Shortening Cycle Function in Youth Athletes

Keleher, K, Samways, B, and Kite, RJ. The influence of somatic maturation on stretch-shortening cycle function in youth athletes. J Strength Cond Res 40(9): e942-e949, 2026-The stretch-shortening cycle (SSC) is a predominant quality underpinning athletic ability. Yet, how the SSC is influenced by the process of growth and maturation in youth athletes is less understood. Therefore, the aim of this study is to further investigate the influence of maturation on SSC performance in both girls and boys. Sixty-five youth athletes (boys = 20, girls = 45) participated in this cross-sectional study. Subjects were assessed for maturational age using the percentage of predicted adult height and then undertook jumping assessment using dual force plates, executing countermovement and squat jump tasks. Applying a Pearson's correlation, moderate to very large associations were determined between jump height ( r = 0.32-0.57) and concentric impulse ( r = 0.54-0.80) with maturational age in both jumping tasks. Boys also demonstrated large associations with RSImod ( r = 0.61) and girls with eccentric braking impulse ( r = 0.53). When exploring differences by maturational grouping (Pre-, Circa-, and Post-PHV) in the girls, the Kruskal-Wallis test identified significant differences ( p < 0.05) in eccentric duration between Pre-PHV and Circa-PHV. In addition, eccentric braking impulse and concentric impulse were greater in Post-PHV than in both Pre- and Circa-PHV. The lack of temporal changes in eccentric duration, yet increases in eccentric impulse, indicated a probable enhanced efficiency of the stretch-shortening cycle post-PHV. Such findings may be attributed to the development of muscle cross-sectional area and architectural changes after maturation. These findings underscore the importance of maturation status when interpreting SSC-related performance tests and developing training programs for youth athletes.