Gastrointestinal profile of symptomatic athletes at rest and during physical exercise

Some athletes suffer from exercise-induced gastrointestinal (GI) disturbances. We developed a profile of GI parameters in 10 symptomatic and 10 asymptomatic athletes both at rest and during exercise. Exercise included 90 min of cycling and running at 70% of maximal power. We measured oesophageal motility, gastro-oesophageal reflux, gastric emptying, orocaecal transit time (OCTT), intestinal permeability and intestinal glucose absorption. During cycling the number and duration of refluxes were increased, whereas gastric emptying showed no differences between rest, cycling and running. The OCTT was increased in the running trial, compared to rest (P=0.005). Also, intestinal permeability was higher in the running trial, compared to rest (P=0.008). There were no differences in intestinal glucose absorption between rest and exercise. Compared with asymptomatic athletes the symptomatic subjects had a higher intestinal permeability (P=0.001), more reflux episodes (P=0.03) and a longer duration of reflux (P<0.05) during cycling. No differences were observed at rest. In conclusion, there is no difference in GI profile between symptomatic and asymptomatic athletes at rest. During exercise, symptomatic subjects have a longer OCTT and a higher intestinal permeability, which is more pronounced during running than during cycling.