Gastrointestinal bleeding in marathon runners

Scand J Gastroenterol. 1986 May;21(4):493-7. doi: 10.3109/00365528609015168.


Gastrointestinal bleeding has been proposed to be a contributing factor in the development of 'runner's anaemia'. To study the incidence of gastrointestinal bleeding, 2-3 prerace and 2-3 postrace faecal samples from 63 marathon runners were tested for the presence of blood. Five of the participants had faecal blood before but not after the race. A reasonable explanation for the bleeding was found for four. Eight runners (13%) had positive tests for faecal blood after the competition. Clinical investigation disclosed no gastrointestinal disease. Postrace haematuria was discovered in another 13% of the runners. None of the runners observed overt gastrointestinal bleeding or haematuria, nor did anyone develop anaemia. Gastrointestinal disturbances related to running were reported by 54%. It is concluded that gastrointestinal complaints and gastrointestinal bleeding are prevalent among marathon runners.

MeSH terms

  • Adolescent
  • Adult
  • Athletic Injuries / etiology*
  • Female
  • Gastrointestinal Diseases / etiology
  • Gastrointestinal Hemorrhage / epidemiology
  • Gastrointestinal Hemorrhage / etiology*
  • Hematocrit
  • Hematuria
  • Hemoglobins / analysis
  • Humans
  • Male
  • Middle Aged
  • Physical Endurance
  • Proteinuria
  • Running*


  • Hemoglobins