Male adult mice were fasted for 8-10 hr, given a 1% phenol red marker solution, and exercised on a treadmill. Mice exercised at 0.50 mph had significantly faster gastric emptying rates after 15 min of exercise than non-exercised mice; however differences were not significant for longer periods of time. Mice exercised at 0.25 mph did not have significantly different gastric emptying rates at any time interval studied. Larger volumes empty faster than smaller volumes from stomachs of exercised mice.