The effects of different velocity loss thresholds on post-activation performance enhancement in basketball players.

Aim: This study investigated the effects of different velocity loss (VL) thresholds during squat exercise at 80% of one-repetition maximum (1RM) on post-activation performance enhancement (PAPE) in basketball players. Methods: Nineteen male collegiate basketball players completed three familiarization sessions and four randomized crossover experimental sessions: control (passive rest), 5% VL, 10% VL, and 20% VL. Countermovement jump height (JH), peak power output (PPO), and reactive strength index modified (RSIm) were measured pre-test and at 3-min and 8-min post-squat. Linear mixed-effects models (LMMs) evaluated the effects of time, condition, and mean-centered relative strength on the outcome variables and repetition counts. To identify responders who exhibited meaningful improvements in jump height, the smallest worthwhile change (SWC) was calculated. Results: At the group level, no significant condition × time interactions or main effects of condition were observed for JH, PPO, or RSIm ( Conclusion: Squat protocols using 5-20% VL at 80% 1RM did not produce significant group-level CMJ performance improvements, suggesting that a comprehensive warm-up may create a performance ceiling. Furthermore, these responses were not moderated by relative strength. However, the high inter-individual variability and responder rates at higher VL thresholds highlight the importance of individualized PAPE programming.