Intestinal permeability in runners in the 1996 Chicago Marathon

Abdominal cramping, nausea, diarrhea, and GI bleeding are often reported in long-distance runners. This study set out to determine the effects of prol onged (2-4 hrs) exercise and NSAID ingestion on gastric and intestinal perm eability during the first 5 hrs following the 1996 Chicago Marathon. Thirty -four healthy volunteers (20 M, 14 F; ages 30-50) completed the race and in gested the test solution (5 g sucrose, 5 g lactulose, 2 g rhamnose, in 40 m i water) within 10-15 min. The urinary excretion ratio of lactulose/rhamnos e was used to assess small intestine permeability; sucrose excretion was us ed to evaluate gastric impairment. There were no significant differences fo r mean training mileage, postrace rectal temperature, and percent dehydrati on between runners who ingested NSAIDs and those who did not. In all, 75% o f subjects reported aspirin or ibuprofen ingestion before or during the rac e. Runners who ingested ibuprofen had significant elevations in urinary lac tulose excretion and loctulose/rhamnose ratio, whereas those who ingested a spirin or who did not ingest either NSAID had no significant differences in urinary excretion of lactulose, rhamnose, sucrose, or lactulose/rhamnose r atio compared to resting controls. Thirteen of the 26 NSAID users and 4 of the 8 non-users reported GI symptoms. It is concluded that (a) ibuprofen bu t not aspirin ingestion during prolonged exercise may increase gastrointest inal permeability and lead to GZ symptoms, and (b) prolonged exercise alone can produce GI symptoms.