A practical complex training model for non-athletic populations: a randomized controlled trial on lower-limb power and sprint performance.

BACKGROUND

Explosive power training is increasingly relevant for general fitness participants. While complex training effectively enhances strength and power in athletes, its practicality and efficacy for trained non-athletes using moderate loads and minimal equipment remain unclear.

PURPOSE: This study aimed to evaluate the effects of a practical complex training (CT) protocol-featuring moderate-load resistance and accessible plyometric exercises-on jump performance, sprint acceleration, and reactive strength in physically active young men.

METHODS

Thirty trained young males (≥ 1 year of resistance and aerobic training) were randomly assigned to a complex training group (CTG, n = 15) or traditional resistance group (TRG, n = 15). Both trained 3 times/week for 6 weeks. CTG combined moderate-load resistance and basic plyometrics (e.g., squat + box jump), while TRG followed load-matched resistance-only routines. Tests included squat jump (SJ), countermovement jump (CMJ), drop jump (DJ), reactive strength index (RSI), eccentric utilization ratio (EUR), five-repetition vertical jump (5RVJ), 100-m sprint with segmental splits, standing long jump (SLJ), and 25-m sled drag. Training load was monitored using heart rate-based Training Impulse (TRIMP) and Rating of Perceived Exertion (RPE).

RESULTS

CTG showed no significant gains in CMJ or SJ performance (p > 0.05), but exhibited a significant improvement in EUR (p = 0.016, d = 0.76), with a notable between-group difference at post-test (p = 0.005, d = 0.92). In contrast, significant improvements were observed in DJ height (p = 0.023, r = 0.49), DJ power (interaction p = 0.0002, d = 0.51), and RSI (p = 0.031, d = 0.83). Sprint performance improved significantly in the 0-10 m (p = 0.012, r = -0.54) and 20-30 m (p = 0.016, d = 0.45) phases, with significant interaction effects observed for 100 m total time (p = 0.0035, d = 0.41). No significant changes were noted in SLJ, 25 m sled drag sprint, or 5RVJ metrics.

CONCLUSION

A CT protocol using moderate loads and basic equipment can enhance reactive strength and sprint acceleration in physically active young men, offering a practical and accessible approach for performance gains in general fitness settings.

TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2500112099). Registration Date 10/11/2025 (Retrospectively registered).