Acute Potentiation on Vertical Jump Performance Following Accentuated Eccentric Loaded Back Squats in Male High School Basketball Players

The purpose of this study was to investigate the acute responses of accentuated eccentric loaded (AEL) back squats to induce a postactivation performance enhancement (PAPE) effect in youth athletes across three jump conditions: countermovement jump (CMJ), squat jump (SJ), and novel propulsive-only jump (POJ). Fifteen participants (age: 15.6 ± 1.1 years; RT experience: 1.3 ± 0.9 years; relative strength: 1.32 ± 0.3) three sessions (one familiarization, two experimental). AEL interventions were performed on each experimental session, (3 sets x 3 repetitions) (ECC: 95%, 105%, 115%: CON: 60% 1RM) with pre- and post-testing (3 min, 6 min, 9 min, 12 min). Using a crossover design, random assignment to either (a) CMJ, (b1) SJ+POJ, or (b2) POJ+SJ, where jump height (JH), net propulsive impulse (NPI) and peak relative propulsive power (PRPP) were assessed for each jump. Three 3x5 repeated measures ANOVAs were used to analyze each dependent variable across jump conditions and time. Results revealed a significant increase in POJ JH performance at 9 min (+12.26% ± 13.65%, p \u3c 0.05), whereas CMJ and SJ performance did not show statistically different values from pre-testing for JH, NPI, or PRPP. No significant changes were found for JH, NPI, or PRPP for CMJ or SJ. Although, JH performances peaked at 12 minutes for CMJ (+2.22% ± 7.71%) and SJ (+5.03% ± 12.77%) but did not reach statistical significance. The findings of the study suggest that male high school basketball players may realize superior or unaffected jump performances at 9-12min post-supramaximal AEL back squats. In addition, no significant deficits in performance outcomes were found for any condition from pre- to post-testing. Future research should expand the use of AEL with youth populations, and the practical use of the POJ as a training and performance tool