The Effects of Post-Activation Performance Enhancement on High Intensity Interval Training: A Comparison of Traditional and Cluster Set Protocols

The present study aimed to examine the effects of post-activation performance enhancement (PAPE) protocols employing half-squat exercises, performed using either a traditional set (PAPE(traditionalset)) or a cluster set (PAPE(clusterset)), on peak oxygen uptake (O2peak), the time spent at >= 90% maximal oxygen uptake (VO2max), and total exercise duration during high-intensity interval training (HIIT) in trained athletes. Ten well-trained endurance athletes involved in endurance sport (VO2max: 63.3 +/- 5.1 mL & centerdot;kg(-1)center dot min(-1)) completed three HIIT sessions (until failure x (1-min run at VO2max velocity + 1-min active recovery at 30% VO2max velocity)) under different conditions: (i) control (warm-up only: jogging and stretching), (ii) warm-up + three sets of six repetitions of the half-squat (traditional set; 120 s of rest between sets), and (iii) warm-up + three sets of 2 + 2 + 2 repetitions of half-squat (cluster set; 20-s rest after each two-repetition cluster and 80-s rest between sets). No significant differences were found in O2peak responses among the three HIIT protocols (control: 62.3 +/- 5.1 mL & centerdot;kg(-1)& centerdot;min(-1); PAPE(traditionalset): 61.6 +/- 4.0 mL & centerdot;kg(-1)& centerdot;min(-1); PAPE(clusterset): 61.9 +/- 3.7 mL & centerdot;kg(-1)& centerdot;min(-1); p = 0.198). However, both PAPE protocols increased time at >= 90% VO2max (control: 6.21 +/- 0.9 min; PAPE(traditionalset): 7.43 +/- 1.2 min; PAPE(clusterset): 8.11 +/- 1.4 min; p < 0.001) and total work duration (control: 12.0 +/- 0.96 min; PAPE(traditionalset): 13.4 +/- 1.54 min; PAPE(clusterset): 14.4 +/- 1.53 min; p < 0.001) compared with control. Additionally, the PAPE(clusterset) resulted in a significantly longer time spent at >= 90% VO2max (p = 0.005) and total work duration compared with the PAPE(traditionalset) (p = 0.043). PAPE protocols, especially using cluster sets, increase time >= 90% VO2max and total work duration during HIIT, potentially enhancing endurance performance.