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Background and Objective: Differentiation of white adipose tissue into brown through hormonal and non-hormonal factors, causes weight loss and weakens in obese and overweight people. This study was performed to determine the effect of 12 weeks of interval exercise with different intensities on serum levels of fibroblast growth factor 21 and myostatin in obese and overweight males.
Methods: This clinical trial study was done on 47 obese and overweight males (20.5±0.73 years old). Subjects were randomly divided into four groups: control, interval exercise with low intensity, moderate intensity and high intensity. The exercise program consisted of 12weeks of interval exercise with light, medium and heavy intensity respectively with 58-63, 73-78 and 88-93 percent of Reserve heart rate for 25 to 63 minutes and three sessions per week. Serum indices of fibroblast growth factor 21 and myostatin were measured using fasting blood sample 48 hours before and after exercise program using ELISA method.
Results: Performing 12 weeks of interval training with different intensities was not contribute to significant changes in the serum levels of fibroblast growth factor 21 and myostatin. Implementation of interval exercise at moderate and high intensities was associated with reduction of body fat percentage and increasing in maximal oxygen consumption (VO₂max) in overweight and obese men (P<0.05).
Conclusion: Performing 12 weeks of low, medium and high intensity interval training without changing the serum level of fibroblast growth factor 21 and myostatin has a beneficial effect on improving body composition and increasing VO₂max in obese and overweight young males.