Effects of acute graded exercise on human colonic motility

Whether physical exercise stimulates colonic motility is unclear. Our aim w as to determine the immediate effects of graded exercise on colonic motilit y. Colonic motility was recorded at six sites in 11 untrained subjects, by colonoscopically placing a solid-state probe. Subjects were free to ambulat e. The next day, subjects exercised on a bicycle at 25, 50, and 75% of peak oxygen uptake for 15 min, with each followed by a 15-min rest. Motor patte rns, motility indexes, and regional variations before, during exercise, dur ing rest, and during postexercise periods were compared. During exercise, t here was an intensity-dependent decrease (P < 0.001) in the number and area under the curve of pressure waves. The incidence of propagated or simultan eous pressure waves and cyclical events also decreased (P < 0.05). After ex ercise, the pressure activity reverted to baseline, but the number and ampl itude of propagated waves increased (P < 0.01), whereas the simultaneous wa ves and cyclical events remained lower. Acute graded exercise decreases col onic phasic activity. This may offer less resistance to colonic flow, where as the postexercise increase in propagated activity may enhance colonic pro pulsion.