Runners Now Cautioned Against Drinking

Bucking traditional wisdom, some doctors are now cautioning runners against drinking too much during intense exercise. According to new research published in the New England Journal of Medicine, an increasing number of athletes are severely diluting their blood by drinking too much fluid. The research involved 488 runners in the 2002 Boston Marathon. The runners gave blood samples before and after the race. These samples revealed that 13 percent had drank so much that they had hyponatremia, or abnormally low blood sodium levels. In three cases, the levels were so low that they were in danger of dying. Apparently, intense exercise prevents the kidneys from excreting excess water. As people keep drinking, the extra water moves into their cells, including brain cells. The engorged brain cells, with no room to expand, press against the skull and can compress the brain stem, the results of which can be fatal.