Effect of progressive aerobic training on leptin, insulin, cortisol and testosterone in obese sedentary men

Hypothalamic – pituitary- adrenal (HPA) axis and leptin changes have main role in the development of obesity. The purpose of this study was to investigate the effect of progressive aerobic training on leptin, insulin, cortisol, and testosterone in obese sedentary men. 30 obese sedentary men was randomly divided into exercise (n=15) and control (n=15) groups. The exercise group performed an aerobic training with 55-70% of heart rate reserve, 3 days per week for 12 weeks. Body fat percentage and serum levels of leptin, cortisol, testosterone, insulin, and glucose were measured at baseline and after training. The results showed that 12 weeks of progressive aerobic training caused a significant decrease in body fat percentage (P= 0.001), and serum leptin (P=0.001). Also a significant increase in serum testosterone level was observed (P= 0.001). However, no significant changes were found in the cortisol and insulin hormone levels, and insulin resistance (P>0.05). Also, there was a significant relationship between changes in the serum levels of leptin and changes in the percentage of body fat (P=0.035, r= 0.48). Finally, it can be concluded that the progressive aerobic training can reduce serum leptin levels in obese men. However, this training had no effect on the alterations in the levels of cortisol and insulin, as well as insulin resistance in obese sedentary men. Reduction of serum leptin levels may be associated with a change in the body fat.