The effect of a 12-week combined training program on serum leptin, C- reactive protein and the insulin resistance index in overweight men

Physiological stress resulting from physical activity is one of the potential regulators of leptin secretion from adipose tissue. Thus, the purpose of this study was to examine the effects of a 12-week combined training (CT) program on serum leptin, C-reactive protein (CRP) and the insulin resistance index (HOMA-IR) in over weight men. In this quasi-experimental study, 30 sedentary men (20.97±1.9 years old, and body mass index (BMI) of 26.47±0.75 kg.m-2) were randomly allocated into the experimental (n=20) and control (n=10) groups. The experimental group performed a CT program (aerobic exercise: 60%-70% of their maximal oxygen uptake for 20 min and resistance exercise: 2 sets of 10 repetitions at 70% of 1 repetition maximum). The control group did not perform the physical exercises. At the end of the CT, blood samples were collected from the experimental group. Dependent variables were measured before and 12 weeks after the CT program. At the end of the 12 weeks, there were a significant reduction in serum CRP (1.45±0.27 mg. l-1 versus 1.39±0.3 mg. l-1, P<0.05), leptin (7.27±0.68 ng.ml-1 versus 7.24±0.65 ng.ml-1, P<0.05) and insulin resistance index (1.6±0.14 versus 1.5±0.23, P<0.05). A 12-week CT program can cause to decrease leptin, CRP and insulin resistance index in over weight men, and this improvement occurred in the presence of increased cardio respiratory fitness but is independent of measurable changes in weight and BMI.