Effects of Maturation Status on Physical Performance Adaptations Following a Combined 7-Week Strength and Power Training Program in Elite Male Youth Soccer Players

This study investigated the adaptations induced by a 7-week training protocol combining strength and power training with regular soccer training in young elite soccer players, considering their maturity level. Thirty-five participants were categorized into three training groups according to their maturation status. They were classified based on their relative age and peak height velocity (PHV) as: Pre-PHV, Mid-PHV, and Post-PHV. Each group engaged in a 7-week program, combining their regular soccer training with two resistance sessions per week (one strength and one power session). Before and after the training program, the following tests were conducted: eccentric hamstring strength using the Nordic Hamstring Exercise (NHE), countermovement jump (CMJ), sprint with split times at 10 and 30 m, and Change of Direction and Acceleration Test (CODAT). The Pre-PHV group exhibited significant improvements in sprint performance (p < 0.02), while the Mid-PHV and Post-PHV groups showed enhanced performance in CODAT (p = 0.01 and p = 0.05, respectively). Notably, the Post-PHV group displayed improvements in the NHE (p < 0.05), but also experienced a decline in sprint performance (p < 0.01). The training protocol produced substantial enhancements in 10 and 30 m sprint times for the Pre-PHV and Mid-PHV groups relative to the Post-PHV group (p < 0.02), while the Post-PHV group achieved greater advancements in NHE compared to the Pre-PHV group (p < 0.01). No significant differences were found between Pre-PHV and Mid-PHV groups across all assessed parameters (p > 0.01). These findings demonstrated that the same strength training program led to different adaptations depending on the participants’ maturation status; therefore, this aspect should be carefully considered when designing training programs for young soccer players.