Today I lost 4 pounds in one hour!
It was 79°F and 85% humidity this morning. So I decided it would be a good day to measure my sweat rate.
I weighed myself before I headed out for my run, and then when I got back an hour later.
I lost exactly 4 pounds, or 1.8 kg.
Since I didn't drink anything or pee during my run, that is roughly 1.8 liters of sweat. Or around a ½ gallon.
Yes, this is gross, but it is also good to know.
If I had tried to run a marathon today, I would need to drink about 2 gallons of water to keep up with sweat loss. How many little cups of water at the aid stations is that?
Figure about 4 oz per cup, thats about 64 cups. Wow.
Probably the hottest marathon I ever ran was Chicago 2008 which got to 80° by the end (not as bad as 2007).
I think I drank 2 cups every mile, which is 42 cups. I guess that was a good strategy, because I was fine at the end.
I think I will try this at different temperatures. I would be good to know how much to drink given a particular pace/temperature.