Effect of 6 months of aerobic exercise training on serum leptin, cortisol, insulin and glucose levels in thin middle-aged women

Leptin is a peptide hormone which is basically secreted by adipose tissue and regulates the energy metabolism and balance and therefore controls the body weight. Effect of long term exercise on serum leptin levels is unclear. This research was performed in order to investigate the effect of six months aerobic exercise on serum leptin, cortisol, insulin and glucose levels in middle-aged women. This quasi-experimental study was performed in year 2009 on 19 healthy middle-aged women who were selected by accidental sampling method. Subjects were randomly divided into two experimental (11 subjects) and control (8 subjects) groups. The Exercise protocol included aerobic exercise for 6 months and 3 sessions per week and every session lasted 60 minutes with intensity of 60-70% of heart rate reserve. Data was analyzed by SPSS 16 software using descriptive and inferential statistical methods including independent t-test for investigation of inter-group changes. Mean of variables did not change significantly from pre-test to post-test in two experimental and control groups. Six months of aerobic exercise did not induce significant change in individual's weight and body mass index and serum levels of leptin, cortisol, insulin and glucose. Six months of aerobic exercise does not induce significant change in serum levels of leptin, cortisol, insulin and glucose in thin middle-aged women. Regular physical activity probably causes decrease in serum leptin level if body mass index and body fat mass reduce simultaneously.