Exercise-induced weight loss can occur for several reasons including changes in circulatory levels of appetite-regulating hormones. The purpose of this study was to compare the effect of various trainings on fasting serum levels of acylated ghrelin, Peptide YY (PYY3-36) and Glucagon-like peptide-1(GLP-1) as well as weight and BMI changes. 44 overweight men were randomly assigned into 4 groups of 11 individuals including: endurance (3 sets of 10 minutes with 80-90% of HRmax), resistance (4 sets of 8 repetitions with 80% of 1RM), concurrent (combination of programs of endurance and resistance groups in an alternate manner) and control groups. Training protocols were conducted for 12 weeks and 3 sessions per week. Results showed that all three types of training programs resulted in weight loss (p=.000, P=.000 and P=.036 for resistance, concurrent and endurance groups, respectively), BMI reduction (p=.000, P=.000 and P=.034) decreased serum acylated ghrelin (p=.000, P=.000 and P=.004) and increased PYY hormone levels (p=.028, P=.035 and P=.036). However, the effect of resistance training on these changes was more pronounced. Moreover, none of the exercise programs had any effect on serum levels of GLP-1. In addition, there was a significant positive correlation between weight (.003) and BMI (.009) changes with ghrelin while a negative correlation was observed between weight (.003) and BMI (.03) changes with PYY. The findings suggest that regular exercise training, in particular resistance training, is likely to reduce body weight and improve body composition of overweight inactive people by suppressing orexigenic hormones and stimulating the anorexigenic hormones.
