Purpose To determine the effects of mild physical activity on intestinal gas transit and clearance. Methods In 8 healthy adults, a gas mixture was infused continuously into the jejunum (12 mL/min) for 120 minutes with simultaneous duodenal lipid perfusion (1 kcal/min). Gas evacuation, perception of abdominal sensations (on a scale of 0 [none] to 6 [pain]), and abdominal girth were measured at 15-minute intervals during rest and intermittent pedalling, with subjects in a supine position. Results Mean (± SD) intestinal gas retention was lower during exercise than at rest (-84 ± 303 mL vs. 143 ± 219 mL, P <0.05). Gas retention during rest was associated with significant abdominal distension (8 ± 6 mm, P <0.01 vs. basal), which was decreased with exercise (3 ± 7 mm, P <0.05 vs. rest). The gas challenge test was well tolerated both during exercise and rest (perception score: 0.6 ± 0.5 vs. 0.9 ± 0.4, P = 0.25). Conclusion In healthy subjects, gut transit of intraluminal gas is enhanced by mild physical activity. © 2004 by Excerpta Medica Inc.