Effect of aerobic exercise on mouth-to-cecum transit time

Gastroenterology. 1989 Mar;96(3):938-41.


To examine the premise that exercise reduces the gastrointestinal transit time, we evaluated the effect of walking 4.5 km in an hour on mouth-to-cecum transit time. Twenty-three healthy volunteers, 9 men and 14 women, with an age range of 19-28 yr, were studied. After an overnight fast, the subjects ingested 10 g of lactulose in 150 ml of water while breath hydrogen concentrations were analyzed at 15-min intervals. On separate days, in random sequence, subjects either sat in a chair or walked on a treadmill for 60 min. Mean transit time was 55 +/- 8 min when resting and 89 +/- 4 min when exercising (p less than 0.001). In conclusion, light aerobic exercise prolonged the mouth-to-cecum transit time. On the basis of this observation, exercise as a causative factor in runner's diarrhea and its value in the management of chronic constipation may be questioned.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Breath Tests
  • Exercise*
  • Female
  • Gastrointestinal Transit*
  • Humans
  • Hydrogen / analysis
  • Lactulose
  • Male


  • Lactulose
  • Hydrogen