The Effect of a Single Session Aerobic Exercise on Plasma Ghrelin, GH, Insulin and Cortisol in Non-Athlete University Male Students

Ghrelin, a peptide hormone secreted from the endocrine cells of stomach, affects appetite, energy consumption, weight, and body composition. Although the effects of endurance exercise on weight loss have been demonstrated, results on the impact of this exercise on ghrelin levels are controversial, and are from studies performed in athletes. The aim of this study was to investigate the response of serum ghrelin, growth hormone, and cortisol after a single session of aerobic exercise in young non-athlete male students. Sixteen non-athlete male students, randomly selected, performed a single session of aerobic exercise, including 3 consecutive- one mile running sessions with 3 minutes rest period at the end of each mile. The participants in this study had a mean age 22.7±2.1 years, weight 72.8±5.7 kg, height 177.9±5.7 cm, and body mass index 23.2±1.7. To determine levels of these hormones, plasma ghrelin, GH, insulin, and cortisol, blood samples were taken, using the ELISA method. The results of paired-samples t-test showed that the levels of growth hormone and ghrelin increased significantly in the plasma, whereas insulin and cortisol levels decreased (P<0.05). These data suggest that a single session of aerobic exercise can decrease energy reservoirs and increase ghrelin secretion in response to energy deficit to supply and balance the sources of energy loss. Therefore it is clear that activity duration is an important parameter in the increase in ghrelin levels in response to exercise.