Delayed effects of post-activation performance enhancement using flywheel resistance versus traditional free weight protocols on countermovement jump and 10-m sprint performance

Abstract

This study examined the delayed effects of two post-activation performance enhancement (PAPE) protocols— traditional free-weight squats (TR) and flywheel isoinertial squats (FW)—on performance changes measured 48 h after intervention. Fourteen resistance-trained male athletes (age: 23.0 ± 1.5 years; height: 180.4 ± 6.6 cm; weight: 77.1 ± 6.9 kg) from five different sports completed both protocols in a non-synchronous crossover design. Each protocol involved 3 sets of 6 maximal squat repetitions. The TR protocol was performed at each participant's individual power maximum (mean load: 114.3 ± kg; Pmax: 957.7 ± W), while the FW protocol used isoinertial loading with a mean inertia of 0.117 ± kg·m2 (Pmax: 1060.6 ± W). Performance outcomes were assessed through 10-meter sprint and countermovement jump (CMJ) tests conducted at baseline and 48 hours after each intervention. The TR protocol led to a statistically significant improvement in 10-meter sprint time (p = 0.022, d = 0.667), whereas the FW protocol did not show significant changes (p = 0.126, d = 0.420). CMJ height significantly improved after both TR (p = 0.001, d = 1.052) and FW (p = 0.004, d = 0.902) protocols. No significant differences were found between protocols in either sprint or CMJ performance changes. Traditional resistance squats may elicit a delayed improvement in sprint acceleration 48 hours post-exercise, while both TR and FW protocols appear effective in enhancing vertical jump performance after the same recovery period. These findings suggest that properly structured PAPE interventions can lead to meaningful performance gains even beyond the typical acute window, highlighting their practical relevance for mid-term athletic planning.