Effect of moderate-intensity exercise session on preprandial and postprandial responses of circulating ghrelin and appetite

Responses of plasma total ghrelin and appetite were investigated during preprandial and postprandial stages of recovery from a moderate-intensity cycling session. Healthy recreationally active men underwent one exercise and one control trial. In the exercise trial, subjects exercised for approximately 60 minutes, while in the control trial they rested quietly for the same duration. After the intervention, subjects rested for 120 minutes and then consumed a test meal. Measurements were obtained immediately and 120 minutes after the intervention and then during 180 minutes of the postprandial period. The post-intervention concentration of total ghrelin was lower (p<0.05) in the exercise than in the control trial. The modulating effect of exercise was related to the reduction in the postprandial rather than preprandial concentration. Post-intervention scores of appetite were not different between the two trials, but when preprandial and postprandial responses were considered separately, postprandial hunger and desire to eat was higher (p<0.05) in the exercise trial. In summary, during recovery from moderate-intensity exercise, total ghrelin does not respond in a compensatory manner to disturbances in energy balance. Thus, an exercise-induced increase in appetite during the later stages of recovery coinciding with the postprandial state cannot be explained by changes in the plasma concentration of total ghrelin.