Effect of conditioning contraction with different intensities on vertical jump performance

Abstract

BACKGROUND: Post-activation potentiation is the phenomenon of increased muscle power when preceded by a high intensity conditioning activity (CA).
OBJECTIVE: To verify the acute effect of three different intensities of conditioning activity on the vertical jump performance.
METHODS: Fifteen men with strength training experience visited the laboratory on six occasions. The first two visits were intended exclusively to identify the 1RM load in the squat exercise. The other visits were carried out at random, comprising three experimental conditions and one control. The experimental procedures were composed with the CA performed in 3 sets of 3 repetitions with 20,55 or 90% of 1RM in the squat exercise. Before and 10 minutes after performing the CA, the volunteers performed 3 vertical jumps. In the control visit, no CA was performed between the sets of jumps. As a dependent variable, both the highest height obtained (best performance) and the average height of each sets of jumps were considered. After checking the normality by the Shapiro-Wilk test, a two-way ANOVA with repeated measures was used to check if there was an interaction or main effect. The level of significance was p<0.05.
RESULTS: Two-way ANOVA with repeated measures did not observe group x test interaction (p=0.938) and neither main group effect (p=0.486) nor test (p=0.658) when considering the average of the 3 jumps. The same result was observed when the best performance jump was evaluated (p=0.582; p=0.873; p=0.119).
CONCLUSION: The protocols adopted in the present study do not seem to interfere with the vertical jump performance for individuals experienced in strength training, but not athletes. Biological individuality is an important influencing factor, indicating the need to test individual performance before prescribing this training model.