Effect of progressive resistance training on insulin resistance and plasma adiponectin concentration in overweight men.

Background and objectives: The purpose of the present study was to examine the effect of a progressive resistance-training program beside an energy deficit diet on body Composition, insulin resistance and plasma adiponectin levels in overweight adult men. Methods: Twenty-five overweight men (age =32.1 ± 4.3 years, BMI =28.9 ± 1.3 kg.m-2) were randomly assigned into one of the two groups: resistance training+ diet (RD, n =15); and diet only (DO, n =12). Both groups undertook a 12-week weight loss program using a moderate isocaloric energy deficit. Results: After 12 weeks intervention, there was equivalent significant weight loss for both groups (p <0.01). Total and abdominal fat mass, fasting insulin concentration and HOMA-IR score were decreased in both groups (p <0.01). All previously mentioned variables except fasting insulin levels were more significantly reduced in RD compared to DO group. There was a significant decrease in lean body tissue only in DO (p <0.01) group. We did not find any significant changes in plasma adiponectin concentration of the experimental groups. Reduction in insulin resistance had a significant positive correlation with abdominal and total fat loss (p < 0.05) and a negative correlation with lean mass loss (p < 0.05). Conclusion: Adding a progressive resistance-training program to an energy deficit diet, without any change on magnitude of weight loss could prevent the loss of lean body mass and improve the reduction of total and abdominal fat mass and insulin resistance. Moreover, the change in body composition and insulin resistance was accompanied with no significant change in plasma adiponectin.