Influence of the Intensity of Squat Exercises on the Subsequent Countermovement Jump Performance

Abstract

Jump performance can be augmented after performing squat exercises, and this is thought to be because of the phenomenon of postactivation potentiation (PAP). The influence of the intensity of squat exercise on jump performance is yet to be fully elucidated however. Thus, the aim of this study was to examine the influence of the intensity of squat exercise on the subsequent jump performance. Ten injury-free, recreationally trained men (mean ± SD, age, 21 ± 2 years; body mass, 90.8 ± 11.9 kg; height, 181.3 ± 5.7 cm; 3RM BS, 134 ± 22 kg; 6RM BS, 120.5 ± 21.3 kg) agreed to participate in the study. On separate days in a counterbalanced randomised order, participants performed 3 baseline countermovement jumps (CMJs) on a force plate where jump height (JH), peak power (Ppeak), rate of power development (RPD), peak rate of force development (PRFD), and peak vertical force (Fpeak) were measured, followed ten minutes later by one of two conditioning activities; either (a) 1 set of 3 repetitions at 3RM (~93% 1 repetition maximum [RM]), or (b) 1 set of 6 repetitions at 6RM (~85% 1RM) parallel back squats. 7 minutes post squats, participants performed a further 3 CMJs which served as post-intervention CMJs. A paired-samples T test found no significant pre- to post-intervention changes for any of the variables (p > 0.05) examined in either loading condition (3RM and 6RM). In addition, delta values (difference post CMJ – baseline CMJ) indicate that there were no significant differences in dependent variable between the 3RM and 6RM squat condition (p > 0.05; JH, 0.2 ± 3.8 vs. -0.6 ± 2.2; Ppeak, 15.4 ± 229 vs. -40.4 ± 134.1; RPD, -28.5 ± 1,854.2 vs. 887.9 ± 3,341.9; PRFD, -1.1 ± 3 vs. -0.1 ± 1.3, Fpeak, 43.7 ± 362.2 vs. -52.2 ± 379.8). However, JH was nonsignificantly (p > 0.05) increased following the high-intensity squat exercise (3RM). In conclusion, a high-intensity squat exercise is better than a moderate-intensity squat exercise for recreationally trained men to use as a warm-up procedure for enhancing subsequent jump performance.