Gastrointestinal Regulatory Peptide Responses in Long-Distance Runners

Abstract

In brief: Diarrhea is a common complaint of recreational and competitive runners. To test the hypothesis that running stimulates gut motility through a hormonal mechanism, we studied the effects of a 30-km run on plasma concentrations of gastrointestinal (GI) regulatory peptides in seven male marathon runners. Concentrations of insulin, enteroglucagon, neurotensin, and gastric inhibitory polypeptide did not change, but gastrin, motilin, somatostatin, pancreatic glucagon, pancreatic polypeptide, and vasoactive intestinal polypeptide increased. Epinephrine and norepinephrine also increased, which may partly explain the concentration changes. The increase in motilin was sufficient to stimulate gastric emptying and colonic motility, but further research is needed to determine whether these hormonal changes affect Gl function.