« Getting fat, part IV | Main | Cold rain, snow, and some wind, part III »
April 15, 2005
Too much water
Both Mom and the DRS list noticed the NYT article saying some runners are drinking way too much to avoid dehydration, and are actually putting themselves into danger of having too much liquid in their systems. People have died from swelling their brain cells with water.
"Drink before you're thirsty" is right. "Guzzle gallons whenever possible" is silly.
Last summer I ran half-marathon distance when it was 34 C (93 F) outside. It took me about 90 minutes, and I did it without drinking. That was stupid:
At 1:01:30, I was feeling pretty thirsty. At 1:15, I was drying out. At the end, I was sweating less than when I ran 10k yesterday, even though today was hotter. Need to figure out how to take some water for runs that long.
That day I should've been drinking something. But that doesn't mean I'm going to go out Sunday and drink a liter of water at every stop. My aim is more along the lines of 20-25 cl every 5 km. That works out to 1.6-2 liters over the marathon distance. If I lose 1 liter/hr, that means I'll be 1 liter down over the whole distance. So if I also drink in the morning, then a glass of something right before going out, then a little bit after the race I should be fine. Even after running hard for over 20 mi, my kidneys were functioning normally by lunchtime.
Posted by Mark at April 15, 2005 09:12 PM
Comments
If I remember correctly, I have read something to the effect that you can lose 3% of your body weight in fluid without significantly affecting performance and you can lose up to 6% of your bodily weight in fluid without bringing on the most dangerous health effects from dehydration. That is a lot of fluid to lose before there are dangerous problems. 6% of your body weight would be about 11 pounds which is getting on towards 1.5 gallons of fluid.
Posted by: Dana at April 16, 2005 02:47 AM
Exactly. So for me there's no point to guzzle liquids. Part of drinking is for comfort. If you stay hydrated, you feel better than you would if you don't.
Posted by: Mark at April 16, 2005 08:31 PM