Cover Image

PAPERBACK
$99.00



View/Hide Left Panel
  • Do GI symptoms and morphological changes associated with exercise-heat stress persist or do they subside quickly without functional impairment?

GASTROINTESTINAL SYMPTOMS

One of the first and most dramatic accounts of GI distress came from Derek Clayton (Benyo and Clayton, 1979) after he ran the marathon in 2:08:33.6. He commented:

Two hours later, the elation had worn off. I was urinating quite large clots of blood, and I was vomiting black mucus and had a lot of black diarrhea. I don't think too many people can understand what I went through for the next 48 hours.

Table 4-1 lists the common GI symptoms experienced by runners, although these have also been observed in other athletes (Eichner, 1989).

TABLE 4-1 Gastrointestinal Disturbances Associated with Long-Distance Running

Abdominal cramps

Belching

Gastrointestinal reflux

Flatulence

Bloody stools

Vomiting

Diarrhea

Nausea

They are most often observed with overtraining, dehydration, and the use of aspirin. Another contributing factor may be high ascorbic acid intake (Sharman, 1982). These GI symptoms may be reduced by treatment with cimetidine (Baska et al., 1990) or consumption of an elemental diet (Bounous et al., 1967).

IMPORTANCE OF GI MANIFESTATIONS WITH EXERCISE-HEAT STRESS

Severe heat exposure simulates hemorrhage and intestinal ischemia because blood pools in the cutaneous capacitance vessels, central blood volume and splanchnic blood flow decline, and mean arterial pressure falls because increased heart rate cannot fully compensate for a declining stroke volume that causes cardiac output to fall. Hemorrhage and intestinal ischemia



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement