Post-activation Performance Enhancement Following Maximal Effort, Multi-Joint Isokinetic Eccentric Muscle Actions.

Post-activation performance enhancement (PAPE) is a phenomenon that can enhance muscle performance following maximal or near-maximal muscle actions. While the effects of concentric and isometric conditioning actions on PAPE have been studied, less is known about the influence of eccentric muscle actions. This study investigated the effects of a multi-joint eccentric overload (EOL) protocol on PAPE expressed through countermovement jump (CMJ) height and isokinetic peak force (PF) outcome measures. Twenty-eight recreationally trained participants (18-30 years) completed three visits in a randomized, counterbalanced design. Following familiarization, participants performed either an EOL protocol involving two sets of six maximal isokinetic eccentric actions or a control condition (CON) involving cycling. The CMJ and PF were assessed at baseline and 15 s, 5 min, and 10 min post-exercise. Results showed no significant condition × time interaction or main effect of condition for either CMJ or PF (p > 0.05). However, a significant main effect of time (collapsed across condition) was observed for CMJ (p = 0.019), with post hoc analyses revealing a significantly higher CMJ at 5 min post-exercise compared to 15 s post-exercise (p = 0.037). These findings suggest that this multi-joint eccentric protocol did not effectively elicit PAPE, and therefore may not be optimal for inducing acute performance enhancement. Future research should further elucidate the optimal eccentric loading parameters and muscle action types for inducing PAPE.