The effects of acute exercise on colonie motility

Abstract Changes in colonic motor activity during aerobic exercise were investigated in ten regularly exercising volunteers (five males and five females) aged 27–70 years. Motility was recorded with a catheter containing three solid‐state pressure transducers spaced 5 cm apart. The motility catheter was advanced 40–50 cm from the anal verge by flexible sigmoidoscope without anesthesia at least 60 min prior to testing. Manometric recordings were made from the colon during a 1‐h pre‐exercise rest period, 1 h of jogging at 70–80% maximum heart rate, and 1‐h post‐exercise rest period. The dominant frequency of contractile activity in the colon shifted from 1–4 cpm during rest, to 4–9 cpm with the onset of exercise. Activity also shifted from sporadic, isolated contractions to regular, propagated contractions in six of ten subjects, five of whom reported a history of runner's diarrhoea. The dominant frequency returned to 1–4 cpm during the post‐exercise period. These changes in distal colonie motility may account for the diarrhoea which some subjects experience during intense, acute exercise.