The effect of resistance based post-activation performance enhancement interventions at different loads on maximal voluntary isometric contraction and muscle activation: Preliminary findings

Background The current literature lacks comprehensive information on how load and muscle activation affect performance in resistance exercise-based PAPE interventions. These effects remain unclear, and observations from studies focusing on both muscle activation and performance outcomes are needed to resolve this critical gap. Objective To examine the effects of PAPE interventions on maximum voluntary isometric contraction (MVIC) and muscle activation at different resistance loads via a coherence analysis approach. Methods The first experimental visit included anthropometric assessment, baseline MVIC and one repetition maximum (1RM) tests. In the next two visits, each subject completed a 5-m warm-up and performed the PAPE protocol (high Load or moderate Load) after a 5-m passive rest period. After 7-m of passive transition phase, subjects performed the MVIC and sEMG was recorded during each MVIC. Results We observed a significant load effect on peak force (p < 0.026). This difference was significant (p < 0.038) on the peak force output of the moderate load compared to the control condition, but not between the moderate and high load conditions (p < 1.000). We also observed that load had a significant effect on muscle activation (p < 0.001), and this effect was particularly significant in the high load condition (p < 0.001) compared to the control condition. Conclusion The preliminary findings of the study show that in resistance-based PAPE interventions applied at different loads, the moderate load condition positively affects the force output, while muscle activation increases more significantly, especially at high loads.