A single session of treadmill running has no effect on plasma total ghrelin concentrations

Abstract

Ghrelin is a hormone that stimulates hunger. Intense exercise has been shown to temporarily suppress hunger after exercise. In the present study, we investigated whether post-exercise hunger suppression is mediated by reduced plasma total ghrelin concentrations. Nine men and nine women participated in the study. Their mean physical characteristics were as follows: age 24.8 (s _x  = 0.9) years, body mass index 22.9 (s _x  = 0.6) kg · m⁻², maximal oxygen uptake ([Vdot]O_2max) 57.7 (s _x  = 2.2) ml · kg⁻¹ · min⁻¹. The participants completed two 3-h trials (exercise and control) on separate days in a randomized balanced design after overnight fasts. The exercise trial involved a 1-h treadmill run at 73.5% of [Vdot]O_2max followed by 2 h of rest. The control trial consisted of 3 h of rest. Blood samples were collected at 0, 0.5, 1, 1.5, 2, and 3 h. Total ghrelin concentrations were determined from plasma. Hunger was assessed following blood sampling using a 15-point scale. The data were analysed using repeated-measures analysis of variance. Hunger scores were lower in the exercise trial than in the control trial (trial, P = 0.009; time, P < 0.001; trial × time, P < 0.001). Plasma total ghrelin concentrations did not differ between trials. These findings indicate that treadmill running suppresses hunger but this effect is not mediated by changes in plasma total ghrelin concentration.

Keywords:

• Hunger
• appetite
• exercise
• weight control

Acknowledgements

We thank all of those who participated in this study. None of the authors have any conflict of interest regarding the findings reported in this study.