Adaptations in neuromuscular performance following a 12-week combined in-season training program in youth soccer players

Abstract

Purpose: This study examined the effects of a 12-week in-season combined training program on neuromuscular performance in youth soccer players. Methods: Forty-eight U15 male soccer players (14–15 years) participated via a pre–post repeated-measures design. Participants were divided into 3 groups, a Combined Fitness Training Group (CFTG; n = 16), a Soccer Training Group (STG; n = 16), and a Control Group (CG; n = 16). The intervention lasted 12 weeks during the competitive season and consisted of 4-weekly training sessions and one match. The CFTG followed a combined training program in addition to soccer training with functional strength training, sprint development, change-of-direction (COD) drills, and intermittent aerobic training, while the STG followed a program with physical condition being trained only with soccer training. Squat jump (SJ), countermovement jump (CMJ), CMJ with arm swing (CMJ-AS), 10–20–30 m sprint tests, Illinois agility (right and left), were used for the assessment of neuromuscular performance. A repeated measures ANOVA was performed for statistical analysis. Results: Significant interactions were observed for sprint (10–20–30 m; p<0.001), vertical jump (SJ, CMJ, & CMJ-AS; p<0.01), and Illinois tests (p<0.05). The CFTG demonstrated the greatest improvements, with the largest adaptation observed in CMJ-AS (+19.21%) and 30-m sprint (-3.19%). No changes were detected in CG. Conclusion: A specialized in-season combined training program significantly enhances sprint acceleration, explosive power, and agility in young soccer players compared with soccer-only training. These findings support the integration of targeted neuromuscular conditioning within competitiveseason microcycles in youth soccer academies.