Abstract
Acute exercise significantly reduces hunger in obese and normal body weight individuals. This suppression of appetite is termed “exercise-induced anorexia” and is associated with transient changes in plasma acylated ghrelin concentrations. However, the effects of acute exercise on appetite regulation in competitive athletes currently remain unclear. The aim of the present study was to investigate the effects of acute aerobic exercise on appetite and plasma acylated ghrelin concentrations in athletes and compare them with those in obese and normal body weight subjects. Thirty men (athletes, n = 10; normal body weight, n = 10; obese, n = 10) participated in the present study. Subjects ran on a treadmill at a speed equivalent to 50% of their peak oxygen uptake. During the study period, ratings of subjective feelings of hunger were reported on a 100-mm visual analogue scale. Blood samples were obtained at 30-min intervals for the measurement of plasma acylated ghrelin concentrations. The results obtained showed that plasma acylated ghrelin concentrations were decreased by acute exercise in all groups, whereas hunger rates were unaffected in athletes. Decreases in plasma acylated ghrelin concentrations during acute exercise positively correlated with decreases in hunger rates in the obese and normal body weight groups, but not in athletes. Therefore, aerobic exercise by athletes did not result in “exercise-induced anorexia”. The present results demonstrated that plasma acylated ghrelin concentrations did not significantly affect appetite in competitive athletes.
