Quote:
Originally Posted by
oroy38 
My regimen is about the same (add about 50 cycling miles and 5 running miles) and some weight lifting, and I put down maybe a gallon and a half. Maybe 2 gallons if it's roasting outside and i'm losing A LOT of fluid, and all the while I still take in electrolytes. But for the most part, about 1-1.5 gallons on most days. I've heard of people weighing themselves before and after working out to see if their weight is the same. If their weight is the same (assuming they were adequately hydrated beforehand), then they're doing a good job of replenishing their fluids. I'm not sure of the validity, but it makes sense I guess. Of course, this doesn't account for any electrolytes.
The statement about drinking lots of water depletes electrolytes got me curious, so I checked the label of several multivitamins I have used (from GNC and Centrum). I was delighted to find that they all provide calcium, magnesium, zinc, chromium, chloride, etc. - what I found in some electrolyte supplement.