Weight Loss During Marathon Improves Running Time

Written on December 21, 2023 - 5:43 pm | by EmmyW

Marathoners who lost the most body weight during a race finished more quickly, even though their weight loss exceeded the amount typically recommended for best running performance, according to a new study.

The weight loss reflects a lower level of fluid intake or a faster rate of fluid loss.

Most runners are cautioned to ”hydrate, hydrate, hydrate.” But the new study suggests that might be too much of a good thing for performance results.

“The clear evidence is that drinking just to thirst is the optimum strategy,” says researcher Timothy Noakes, MD, the Discovery Health Professor of Exercise and Sports Science at the University of Cape Town in South Africa.

“Drinking either more or less than to thirst impairs exercise performance,” he tells WebMD in an email. “Drinking more can be fatal, as has occurred to a number of U.S. female marathon runners and soldiers.”

In recent years, U.S. marathons have experienced participant deaths due to excessive intake of water, which can lead to an abnormally low level of sodium in the blood, or hyponatremia.

Fitness Online