Combined lower- and upper-limb post-activation performance enhancement does not clearly improve 50 m front crawl performance in national-level swimmers

Abstract Post-activation performance enhancement (PAPE) has been proposed as an acute strategy to improve sprint-swimming readiness, but the effects of combined lower- and upper-limb conditioning remain unclear. This study examined the acute effects of an individually timed combined lower- and upper-limb PAPE condition on 50 m front crawl performance and selected race-kinematic variables in national-level male swimmers. Fourteen swimmers completed a randomized repeated-measures cross-over design including a control condition and a combined PAPE condition. The conditioning activity consisted of lunge-position squats on a Keiser Squat machine followed by prone butterfly-style double-arm pulls on a Keiser Functional Trainer. The 50 m trial was performed after an individual recovery time based on the upper-limb power-output response. The combined PAPE condition did not significantly improve 50 m performance (25.61 ± 0.81 vs. 25.76 ± 0.83 s; Δ = −0.157 s; p = 0.098; ES = 0.45), although the mean change was directionally favorable. Reaction time and turn time were shorter after PAPE, while stroke rate increased and stroke length and stroke index decreased on both lengths without improving free-swimming velocity. These findings suggest that the tested combined PAPE condition modified selected race components and stroke organization but did not clearly improve overall 50 m front crawl performance.