Effects of Run-Specific Isometric Exercises Performed with Complex Training on Neuromuscular Performance in Youth Soccer Players

The present study explored whether incorporating run-specific isometric exercises (RSIso) into a complex training (CT) routine would provide additional benefits for youth soccer players during the in-season. Twenty-four male athletes (aged 18–19 years) were randomly divided into two groups: one following a conventional CT program and the other performing an identical program preceded by isometric conditioning training (IST-CT). Both interventions were carried out twice per week for eight weeks, with equivalent training volume and intensity. Performance outcomes were assessed through countermovement jump, drop jump, broad jump (BJ), 30-m linear sprint, and the 5-0-5 change-of-direction (COD) tests. Two-way mixed-

Design: ANOVA (between-subjects factor: group [IST-CT vs. CT]; within-subject factor: time [pre vs. post]) revealed significant main effects of time for COD ability with the non-dominant leg (p = 0.01). Significant group × time interactions were observed for peak power (p = 0.01) and BJ performance (p = 0.03), yet post-hoc comparisons did not confirm statistically meaningful differences (all p > 0.05). Overall, both training approaches led to comparable adaptations in strength-speed performance. Although the direction of changes tended to favor the IST-CT condition, the modest magnitude of effects does not allow to draw definitive

Conclusions: regarding its superiority over conventional CT, indicating that further research is required to confirm the practical relevance of these

Findings: .