Monday, August 29, 2016
It's hot, but don't over-drink
In 1985, seventeen runners were hospitalized during the Comrades Marathon. It was hot, so you might guess most were hospitalized due to heat injury or dehydration. You'd be wrong. According to Science Based Running, "nine of them were overhydrated: their blood sodium levels were dangerously low. In the 1987 race, three runners nearly died of the condition, and some runners in the U.S. have indeed died of overhydration" (Science of Running).
Overhydration, called hyponatrimia, is a serious and dangerous condition that can lead problems including confusion, nausea, muscle spasms, comas or death.
While all this sounds scary, there's a simple solution to this potentially dangerous problem. Exercise scientists and nutritionists such as Tim Noakes and Matt Fitzgerald recommend drinking to thirst. You've probably heard, "if you wait until you're thirsty to drink, you're already dehydrated."
This may be true to some degree, but your body is actually pretty good at telling you when its thirsty. We are all an experiment of one, so some may need to drink a bit more. I tend to miss my body's thirst signals, but sometimes seeing a water stop reminds me I'm thirsty. Still, it's better to err on the side of drinking too little than drinking to much.
By all means, drink water and stay hydrated, but as you're doing those long and intermediate distance runs, remember to drink to thirst.
For more information on training and racing in heat, check out the following posts: