The Immediate After-effects of Increased Resistance upon Physical Performance

Abstract It was the purpose of this investigation to evaluate the immediate effects of overload upon vertical jumping performance. Forty-four college men participated in two identical 3-day testing periods during which three levels of overload (no overload, 5 percent and 10 percent of subject's body weight) were applied on a rotational basis. The test sequence involved five pre-overload, three overload, and five post-overload jumps. Paired t tests comparing pre-overload mean scores with post-overload scores indicated non-significant changes for the two experimental conditions but a statistically significant (P<.05) decrement in performance for the control condition. Further analysis of the difference scores (post-overload minus pre-overload) resulted in significant differences (P<.05) between the two experimental conditions and the control. The hypothesis that the application and removal of an overload will lead to an immediate improved performance in vertical jumping is not supported.