EFFECT OF EXERCISE ON MOUTH-TO-CECUM TRANSIT IN TRAINED ATHLETES - A CASE AGAINST THE ROLE OF RUNNERS ABDOMINAL BOUNCING

The role of exercise on the gastrointestinal motor function and in par ticular on transit time is a matter of hard debate, Numerous studies i n the past have failed to demonstrate a consistent effect of short ter m exercise on transit time in untrained subjects and trained athletes. It has been, however, suggested that running, with its constant jostl ing of the abdomen, may have a different effect than exercise performe d in a stationary setting. To examine the effect of running on gastroi ntestinal transit time, 8 healthy male trained runners ingested a lact ulose meal and assigned to rest or exercise on separate days, Exercise consisted of running 9.6 km in an hour, while exhaled gas was sampled every 10 minutes for volume, minute ventilation and hydrogen concentr ation, The mean O-2 consumption was 36.8 ml/min/kg during exercise ses sion and 4.7 mYmin/kg during rest period; Post lactulose rise in hydro gen concentration occurred at a mean of 85+/-25.1 and 84+/1-8.1 minute s for resting and exercise sessions respectively (p=0.732). On the bas is of the present data we conclude that (1) mouth-to-cecum transit tim e is not affected by short term intense exercise in trained athletes; (2) that bouncing of the abdominal content in case of running probably does not change the transit time; and finally, (3) the impact of mode rate to intense short term exercise on the mouth-to-cecum transit is n ot influenced by the subject's fitness state.