Effect of moderate exercise on Crohn's disease patients in remission

Physical exercise may exacerbate the disturbed homeostasis of Crohn's disease patients.

To examine the effect of moderate physical exercise on gastrointestinal function in a group of Crohn's disease patients in remission.

The effect of one-hour's exercise at a maximum of 60% oxygen consumption was evaluated in six males with ileal Crohn's disease in remission on orocaecal transit time (breath test to lactulose), intestinal permeability (6-hours' urinary excretion of a sugar mixture of lactulose/mannitol), polymorphonuclear leucocytes function (peripheral blood chemiluminescence), lipoperoxidation (plasma malondialdehyde) and antioxidant trace elements (urinary and plasma zinc and copper concentrations). Six healthy age-matched subjects served as controls.

Exercise did not elicit subjective symptoms or changes in intestinal permeability and lipoperoxidation. Orocaecal transit time increased after exercise in Crohn's disease patients (72 min +/- 30 vs 100 min +/- 34) with no significant difference from controls (77 min +/- 20 vs 83 min +/- 23). Neutrophils, primed pre-exercise in Crohn's disease patients showed an increased post-exercise chemiluminescence similar to controls. Zinc urinary output significantly increased after exercise in Crohn's disease patients and remained unchanged in control subjects.

Moderate aerobic exercise has no significant effect on the gastrointestinal parameters examined. However, basal neutrophil activation and exercise in Crohn's disease patients may trigger an excessive production of oxygen metabolites. Moreover, exercise may contribute to an increased risk of zinc deficiency.