Effects of Bilateral and Unilateral Eccentric Exercise on Muscle Damage and Muscular Physiological Indices in Healthy Men

Abstract

PURPOSE: This study aimed to determine the effects of bilateral and unilateral eccentric exercises on muscle damage and muscular physiological indices in healthy men.METHODS: Using a randomized crossover design, nine adult males without musculoskeletal disorders were divided into a bilateral eccentric exercise group (BEG, n=9) and a unilateral eccentric exercise group (UEG, n=9). Bilateral and unilateral eccentric exercises involved five sets of six repetitions of the rhythm metronome speed eccentric contraction 3 seconds at 110% one repetition maximum (1RM) using bilateral of BEG and the dominant and non-dominant of UEG separated by four weeks, respectively. Muscle damage (flexed and extended ROM, CIR, and VAS) and muscular physiological indices (muscle activity, muscle fatigue, and muscle tone) were measured before, immediately after (0 hour), 24, 48, 72, and 96 hours following bilateral and unilateral eccentric exercises.RESULTS: The flexed ROM, CIR, VAS, muscle activity, and muscle tone were significantly increased after both bilateral and unilateral eccentric exercises (p<.05, respectively). Extended ROM and muscle activity significantly decreased after both bilateral and unilateral eccentric exercises (p<.05, respectively). However, there was no significant interaction between side (S) and time and side (T×S).CONCLUSIONS: These results showed that there was no difference in muscle damage and physiological indices after measuring and setting the 1RM muscle strength separated by bilateral and unilateral eccentric exercises.