Continuous Jumps Enhance Twitch Peak Torque and Sprint Performance in Highly Trained Sprint Athletes.

Abstract

PURPOSE\nThe objective of this study was to analyze the effects of a conditioning activity (CA) composed of continuous countermovement jumps on twitch torque production and 30-m sprint times.\n\n\nMETHODS\nA total of 12 sprint athletes, 10 men (23.5 [7.7]\xa0y) and 2 women (23.0 [2.8]\xa0y), volunteered to participate in this study. The participants were evaluated in 2 sessions as follows: (1)\xa0to determine the effects of the CA (3 sets of 5 continuous vertical jumps with a 1-min interval between sets) on 30-m sprint performance over time (2, 4, 6, 8, and 10\xa0min) and (2)\xa0to evaluate twitch peak torque to determine the magnitude and time course of the induced postactivation potentiation at the same recovery intervals.\n\n\nRESULTS\nMixed-model analysis of variance with Bonferroni post hoc verified that there was a decrease on the 30-m sprint time at 2\xa0minutes (P = .01; Δ = 2.78%; effect size [ES] = 0.43) and 4\xa0minutes (P = .02; Δ = 2%, ES = 0.30) compared with pre when the CA preceded the sprints. The peak torque of quadriceps also showed significant increase from pretest to 2\xa0minutes (P < .01; Δ = 17.0% [12.2%]; ES = 0.45) and 4\xa0minutes (P = .02; Δ = 7.2% [8.8%]; ES = 0.20).\n\n\nCONCLUSION\nThe inclusion of CA composed of continuous countermovement jumps in the warm-up routine improved 30-m sprint performance at 2- and 4-minute time intervals after the CA (postactivation performance enhancement). Since postactivation potentiation was confirmed with electrical stimulation at the time when sprint performance increased, it was concluded that postactivation potentiation may have contributed to the observed performance increases.