Acute potentiation on propulsive-only jump (POJ) performance following supramaximal accentuated eccentric loading in 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 post activation
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 (back squat 1RM:
body mass; 1.32 ± 0.3) completed three sessions
(one familiarization, two experimental). AEL
interventions were performed on each experimental
session (3 sets x 3 repetitions, with only the initial
repetition of each set was overloaded during the
eccentric phase followed by 2 full repetitions of
nonvarying loads) (ECC: 95%, 105%, 115%; CON:
60% 1RM) with pre- and post-testing (3 min, 6 min, 9
min, 12 min). 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 with a level of significance
of ρ ≤ 0.05. Results revealed a significant increase in
POJ JH performance at 9 min (+12.26% ± 13.65%,
p < 0.05), while CMJ and SJ performance did not
show statistically differences from pre-testing. JH
performances peaked at 12 min for CMJ (+2.22% ±
7.71%) and SJ (+5.03% ± 12.77%) but did not reach
statistical significance. These findings suggest
that male high school basketball players may
realize superior or unaffected jump performances
at 9-12 min post-supramaximal AEL back squats.
In addition, no significant deficits in performance
outcomes were found for any condition from pre- to
post-testing.