Rate Of Velocity Development Less Decreased Following The Repeated Bout Of Maximal Eccentric Exercise

Abstract

It has been reported that rate of velocity development (RVD) and strength are two of important measures of athletic performance, and eccentric exercise-induced muscle damage can be impaired RVD and strength performance (Nguyen et al., 2009 JSRC). It is well-documented that a bout of eccentric exercise confers protection against muscle damage after a subsequent bout of the same exercise performed several weeks to several months later (Clarkson et al., 1992 MSSE), but no study has examined effect of repeated bout of eccentric exercise on changes in RVD. PURPOSE: This study was to test the hypothesis that a repeated bout of maximal eccentric exercise of the elbow flexors would be less decreased RVD and faster recovery in comparison with the first bout. METHODS: Ten untrained young men (21.0 ± 3 yrs) performed 2 bouts of 30 maximal eccentric exercises (MAX1 & MAX2; 30°/s) of the elbow flexors of the non-dominant arm separated by 2 weeks. Maximal isokinetic concentric strength (MVC) and RVD (300°/s), muscle soreness, and range of motion were measured before, immediately after, and for 5 consecutive days after each bout. All data was analyzed by a two-way repeated measures ANOVA. RESULTS: The first bout of maximal eccentric exercise produced significant (P<0.05) decrease in maximal concentric strength (39%), RVD (49%), range of motion, and increase in muscle soreness. The changes in all criterion measures (e.g. MVC: 30%, RVD: 44%) after the second bout of the same exercise were significantly smaller (P<0.05) than that of the first bout. CONCLUSION: These results supported that MAX1 induced significantly muscle damage and soreness would be affected RVD, and protective effect occurred following the first bout of eccentric exercise results in a smaller decrease in RVD and faster recovery when the exercise is repeated after 2 weeks.