BOSTON - USA Track & Field
(USATF) unveiled new fluid-replacement guidelines for long-distance runners, as well as a major
new initiative to educate the distance-running public about how to properly
For athletes in general and especially for those completing a marathon in more than four hours, USATF recommends consuming 100 percent of fluids lost due to sweat while racing. This marks a significant change from the understanding most runners have that they should be drinking as much as possible and following the guideline to "stay ahead of your thirst," which has been held as the standard recommendation for many years. The guideline reflects changes in scientific thinking as well as changes in the average finishing times of marathon fields.
Runners should be sensitive to the onset of thirst as the signal to drink, rather than staying ahead of thirst. Being guided by their thirst, runners prevent dehydration while also lowering the risk of hyponatremia (low sodium), a potentially dangerous condition increasingly seen as runners have erroneously been instructed to over-hydrate. In USATF's new hydration guidelines, long-distance runners are instructed to consume 1 liter of fluid for every liter lost during a race, equaling a 1:1 ratio. Runners can determine their rate of sweat loss weeks before a race by using the USATF Self-Testing Program for Optimal Hydration, as described on www.usatf.org
Runners lose not only water, but significant amounts of sodium and other minerals while sweating during the course of a marathon. Recommendations of 150 percent fluid replacement or more could result in runners consuming large quantities of water during their races, causing a drop in overall sodium levels and, potentially, hyponatremia.
Top of Page
Back to RRM Home Page