Effect of 12 weeks of light and heavy interval training on the level of irisin and fibroblast growth factor 21 in obese and overweight women: A clinical trial study

Increasing the cost of energy in obesity preventing and treating and reducing its complications can be achieved by stimulating the factors including Irisin and FGF21 associated with browning of the white adipose tissue. The aim of this study was to determine the effect of 12 weeks of light and heavy interval exercises on the level of irisin and FGF21 in obese and overweight women. This clinical traial study was done on 35 overweight and obese women (39.8±3.85 years old and body mass index 27.1±3.37 kg/m2). The subjects were divided randomly into three groups of interval exercises including Heavy (n=12), light (n=12), and control (n=11) groups. The training program included 12 weeks of heavy and light interval exercises for 25 to 60 minutes per session and three sessions per week. Before and after the training period, irisin and FGF21 serum indices were measured for each subject. Serum level of FGF21 increased only after 12 weeks of heavy interval training (P<0.05). However, there was no change in serum irisin levels after both heavy and light interval exercises. Body fat percentage, waist to hip ratio, and BMI Subjects of light and heavy interval exercises reduced and VO2max increased significantly compared to control group (P<0.05). 12 weeks of low and heavy interval training without altering serum levels of irisin have a beneficial effect on increasing VO2max and improving body composition. Also, heavy interval training has a significant increase in FGF21, Which can be effective in weight loss through the browning of white adipose tissue.