Comparison of post-activation performance enhancement in the lower limbs of short sprinters based on two velocity loss thresholds.

Objective: The present study examined the effects of post-activation performance enhancement (PAPE) induced by different velocity loss (VL) thresholds on lower-limb explosive performance in sprinters under velocity-based resistance training (VBT). A secondary aim was to identify the optimal VL thresholds (5% and 15%) and recovery time points (PRE, 4, 8, 12, and 16 min) for maximizing PAPE responses. Methods: Using a randomized crossover design, fifteen male sprinters completed two PAPE protocols consisting of deep squats performed at 85% 1RM with two VL thresholds (5% and 15%). Countermovement jump (CMJ) performance (jump height, relative power, and vertical impulse) and 30 m sprint performance (total time used and average speed) were assessed at each time point. The total number of squat repetitions completed under each VL condition was also recorded. Results: In the 5% VL condition, significant improvements were observed in CMJ jump height ( Conclusion: Under two sets of deep squats at 85% 1RM, 5% VL was associated with CMJ improvement at 8 min and 30 m sprint improvement at 4 and 8 min with fewer repetitions, whereas 15% VL improved sprint performance mainly at 8 min with no clear CMJ enhancement.