Gastrointestinal blood loss associated with running a marathon


Gastrointestinal bleeding has been observed in long-distance runners. We prospectively studied participants of the Eighth Annual Marine Corps Marathon to determine the incidence of gastrointestinal blood loss associated with long-distance running. Of 600 runners contacted, 125 (21%) returned a questionnaire as well as pre- and postmarathon stool specimens. Stool specimens converted from Hemoccult negative to positive in 29/125 (23%) of the participants, indicating that running the marathon was associated with gastrointestinal blood loss (P<0.001). The incidence of this conversion (negative to positive) was significant for both males (N=68,P<0.001) and females (N=57,P<0.05). Gastrointestinal bleeding appeared to be independent of age, race time, abdominal symptoms, and the recent ingestion of aspirin, vitamin C, or steak.

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Corresponding author

Correspondence to Col. David A. Peura MD.

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The opinions and assertions contained herein are the private views of the authors and are not to be construed as official policy or as reflecting the views of the Department of the Army or the Department of Defense.

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McCabe, M.E., Peura, D.A., Kadakia, S.C. et al. Gastrointestinal blood loss associated with running a marathon. Digest Dis Sci 31, 1229–1232 (1986).

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  • Public Health
  • Aspirin
  • Blood Loss
  • Gastrointestinal Bleeding
  • Abdominal Symptom