Acute effects of strength training with velocity loss in young adults

Abstract

The relationship between the exertion index and the fatigue index appears to be critical to the effects and subsequent adaptations of strength training in young adults. Velocity-based training methodology allows for immediate adjustment of these parameters, making the dose-response relationship more efficient with each training session. The purpose of this study is to determine the effects of mean propulsive velocity (MPV) based strength training with different percentages of execution velocity loss (VL 10 % and VL 40 %), on the fatigue index and exertion index in a group of untrained young adults. Ten young adults participated in a deep squat training session at 10 % VL and 78 hours later at 40 % VL. The MPV, number of sets and repetitions were recorded to estimate exertion and fatigue indices. Descriptive analysis (mean and standard deviation) and paired sample t-test for difference of means were performed. The best mean MPV of the 10 % VL training was 0.73 (± 0.098); the fatigue index was 5.75 (± 4.42); and the exertion index was 4.50 (± 4.01). The best mean MPV of the 40 % training was 0.72 (± 0.107); the fatigue index was 20.4 (± 5.25); and the exertion index was 15.05 (± 5.28). Statistically significant differences were found in mean MPV (mean 0.11 ± 0.47 p=0.000), mean power (mean 30.63 ± 30.74 p≤0.012), fatigue index (mean -14.11 ± 5.13 p=0.000), and exertion index (mean -10.54 ± 4.40 p=0.000). Adjusting training load and volume based on fatigue and exertion indices could maximize muscle adaptations and minimize the risk of injury during exercise, thus ensuring the long-term sustainability of training programs and strength assessment methods.