Effects of six-week high-intensity interval training (HIIT) on PGC-1α methylation in gastrocnemius muscle of obese rats

Abstract Backgrond:Obesity is associated with increased risk of many diseases. Methylation is an important factor in obesity, indicating epigenetic changes. However, there is lack of data about PGC-1α methylation and regular exercise. The purpose of the present study was to determine effects of a six-week high-intensity interval training (HIIT) program on PGC-1α methylation in gastrocnemius muscle of obese male rats. Methods: In an experimental study, 24 male Wistar rats were randomly divided into four groups (six rats each): control healthy, trained healthy, control obese, and trained obese. Healthy group consumed normal diet and obese group consumed high-fat diet for six weeks. The trained healthy and trained obese performed swimming HIIT for six weeks. Then, 24 hours after the last session of training, gastrocnemius muscles of control and trained rats were extracted and then afterwards PGC-1α methylation was assayed. To analyze the data, paired sample t-test and one-way analysis of variance were used. Results: After six weeks, body weight of trained obese group, compared with control obese, decreased significantly (P=0.021). In addition, after six-week HIIT, PGC-1α methylation of healthy (P=0.010) and obese group (P=0.037), compared with their control group, decreased significantly. Conclusion: It appears that six weeks of swimming HIIT can be effective on obesity state and significantly reduce PGC-1α methylation in gastrocnemius muscle of obese male rats