Runners World article posted by Active.com, the best way to gauge how much you should drink when training or racing is to ... gulp ... let your thirst be your guide.
Here are a few excerpts from the article:
"It's pretty common for athletes to hit at least one or two percent dehydration during endurance events," says Craig Horswill, Ph.D., senior research fellow at the Gatorade Sports Science Institute. "The body's temperature-regulating mechanism is affected even at one percent dehydration."
It is, therefore, Horswill's (and Gatorade's) opinion that even small amounts of dehydration should be avoided because it will affect performance.
At the other end of the spectrum, overhydrating can be even more dangerous than not drinking enough. Hyponatremia occurs when your fluid intake exceeds your rate of fluid loss from sweating, which results in low blood-sodium levels. Symptoms—nausea, disorientation, muscle weakness—can be similar to dehydration. Giving additional liquids to hyponatremic runners only exacerbates the problem by diluting their blood-salt levels even more, which can lead to coma and, in the worst cases, death.
Be sure and read the entire article for the full story on both sides of the argument, but needless to say, the conclusion that the International Marathon Medical Directors Association released came down to one simple prescription: Drink when you're thirsty.
"The new scientific evidence says that thirst will actually protect athletes from the hazards of both over- and underdrinking," said IMMDA.
Isn't the body a remarkable machine? I have been teased by triathlete friends about dragging along an Aquafina for a 5K, but I know that my body needs it.
I also have a friend that can't consume any liquids at all during a race of any length or she gets nauseous.
It really is about the genetic makeup of each individual and no one-size recommendation fits all.
So, go on, ya'll. Keep teasing me about my 20 ounces, and we'll see who's laughing when I pass you to cross the finish line.
Yeah, I know. That last line made me laugh, too.