Changes in gastrointestinal cell integrity after marathon running and exercise-associated collapse

Purpose Endurance exercise and hyperthermia are associated with compromised intestinal permeability and endotoxaemia. The presence of intestinal fatty acid-binding protein (I-FABP) in the systemic circulation suggests intestinal wall damage, but this marker has not previously been used to investigate intestinal integrity after marathon running. Methods Twenty-four runners were recruited as controls prior to completing a standard marathon and had sequential I-FABP measurements before and on completion of the marathon, then at four and 24 h later. Eight runners incapacitated with exercise-associated collapse (EAC) with hyperthermia had I-FABP measured at the time of collapse and 1 hour later. Results I-FABP was increased immediately on completing the marathon (T0; 2593 ± 1373 ng·l −1 ) compared with baseline (1129 ± 493 ng·l −1 ; p