by Brendan M. Lynch | September 01, 2005
Believe it or not, guzzling too much water could have negative even deadly consequences. A study published this past spring in the New England Journal of Medicine found that 13 percent of Boston Marathon runners suffered from hyponatremia, or low blood sodium caused by drinking too much water. That condition can cause “race-related death and life-threatening illness,” according to the study.
    Revised guidelines from USA Track & Field suggest starting an endurance race well-hydrated and not drinking more liquid than you sweat out. Simplified, USATF says, “Be sensitive to the onset of thirst as the signal to drink, rather than staying ahead of thirst.” Most at risk are women and beginning runners who can be slower and therefore spend more time running.
    For travelers involved in their own tests of endurance such as a long hike on a hot day or a grueling bike ride the advice is similar. Instead of chugging water, try moderate amounts of a sports drink containing electrolytes, and have a salty snack, such as pretzels, along the way.