Effects of acute graded exercise on human colonic motility.
Level 3 - non-randomized controlled study
Prospective single-arm within-subject physiological study without a separate randomized control group.
PubMed 10330013 · doi:10.1152/ajpgi.1999.276.5.G1221
What was done
Colonic motility was measured across six sites in 11 untrained subjects using a colonoscopically placed solid-state manometry probe. Following a day of free ambulation, subjects performed stationary bicycle exercise at 25%, 50%, and 75% of peak oxygen uptake for 15 minutes each, separated by 15-minute rest intervals. Investigators evaluated pressure wave counts, area under the curve, propagated vs. simultaneous wave incidence, and cyclical motor patterns across pre-exercise, exercise, rest, and post-exercise phases.
What was found
During exercise, colonic pressure activity showed an intensity-dependent decrease in wave number and area under the curve (P < 0.001). The incidence of propagated pressure waves, simultaneous pressure waves, and cyclical motor events also significantly declined during exercise (P < 0.05). In the post-exercise recovery period, overall pressure activity returned to baseline levels, while the frequency and amplitude of propagated pressure waves significantly increased above baseline (P < 0.01). Simultaneous waves and cyclical motor events remained suppressed post-exercise. Exact numerical means or motility index values were not reported in the abstract.
Why it matters
This study demonstrates that acute exercise acutely inhibits colonic segmental and propulsive contractions in humans, followed by a post-exercise rebound in propulsive wave activity that may promote colonic transit.
Limits
The sample size was very small (n = 11) and restricted entirely to untrained individuals. There was no randomized non-exercising control group or session to control for circadian or diurnal colonic motility shifts. Clinical outcomes, including actual colonic transit time and defecation patterns, were not measured.
Cited by
- supports Eating a meal, exercising, and drinking coffee all stimulate colonic contractions.