The effect of interval versus continuous training on actin and myosin heavy chain levels in adult rat skeletal muscle

Abstract

Objective: Exercise helps maintain and improve contractile proteins and muscle mass. It is necessary to determine which type of exercise and its intensity yields maximal benefits. This study compared the effects of interval versus continuous training on levels of actin and myosin heavy chain (MHC) in the gastrocnemius muscles of adult Wistar rats. Materials and Methods: Twenty male Wistar rats aged 12 months were evenly and randomly divided into three groups: (1) the control group, (2) the interval training group, which consisted of four rounds of running for 4 min (with 1 min of active rest between each run), and (3) the continuous training group, which consisted of 40 min of continuous running. The treatments were given for 8 weeks, 5 days per week. Actin and MHC levels in gastrocnemius muscle were measured using the ELISA. Results: Actin levels in the continuous training group were significantly higher than the interval training group (P = 0.039). We found actin levels in continuous training group were significantly higher than the control group (P = 0.016), but there was no significant difference between interval training and control group (P = 0.624). There were no significant differences in MHC levels between the continuous and the interval training groups (P = 0.231). Conclusion: We found that continuous training was more effective than interval training in stimulating actin proteins in the gastrocnemius muscle.