Resistance exercises incorporated in the warm-up may improve subsequent performance involving explosive movements by eliciting the acute effects of post-activation potentiation (PAP). The aim of this study was to investigate the influence of heavy load back squat exercises included in the warm-up routine on explosive power and speed.
Ten long jump and triple jump male players, who were able to lift twice their body mass in the back squat exercise, participated in the study. On separate days, participants performed countermovement jump (CMJ), standing long jump (SLJ) tests in the laboratory and a 30m sprint test on the track, 4 minutes before and after exercises involving heavy load warm-up. The heavy-load exercises consisted of 1 set of 5 repetitions at 50% of 1 repetition maximum (1RM), followed by the second set of 3 repetitions at 75% of 1RM, followed by 3 sets of ~93% of 1RM. The rest periods were 30 seconds between the first 2 sets, 1 minute between the second and the third set, and 2 minutes rest between the last 3 sets.
A paired-samples T test found significant pre-to post-intervention improvements for all the variables (p < 0.05) including 30 m sprint, standing long jump, and countermovement jump. We concluded that explosive power and speed can be significantly enhanced following a bout of heavy exercise (preload stimulus) involving high-intensity resistance training with multiple sets and adequate recovery.