The Effect of 8 Weeks High-intensity Interval Training on Myostatin and Follistatin Gene Expression in Gastrocnemius Muscle of the Rats

Abstract Background: The purpose of the present study is to investigate the effect of 8 weeks High-intensity Interval Training (HIIT) on the expression of two muscle growth regulating genes (myostatin and follistatin) in gastrocnemius muscle of healthy male rats. Materials and Methods: 16 male Wistar rats were randomly divided into two groups in the same number: control and HIIT. HIIT program was underwent 40 min each session, three sessions in a week for eight weeks. Each exercise training session consisted of 5 min warm-up and cool-down at 40-50 % VO2max, 30 min interval running including 4 min high-intensity (85-90% VO2max) and 2 min active recovery (at 50-60% VO2max). Rats in control group did not do any exercise training program. 48 h after the last training session, rats` gastrocnemius muscle was extracted and the expression of myostatin and follistatin genes was determined by Real Time-PCR. For statistical data analysis, independent t-test was used. Results: The expression of myostatin was significantly reduced 68% in HIIT group in comparison with the control group (p<0.05). However, there was no significant difference in follistatin expression in HIIT group compared to the control group (p>0.05). Gastrocnemius muscle weight was significantly increased 23% in the HIIT group compared to the control group (p<0.05). Conclusion: Results indicated that HIIT lead to significant reduction in the expression of myostatin gene and increase in the weight of gastrocnemius muscle in rats.