If you workout the same intensity in a cool room versus a warm room, you will burn approximately the same amount of calories of energy, but will sweat more in the warm room. Sweat is just lost water. When the body metabolizes fat/protein/sugar one of the byproducts is water, but the vast majority of water in sweat is from the body cooling itself, not energy expenditure.
Work out where you feel comfortable. If a cooler environment is more comfortable, you will get a better workout because you can go more intensely.
I actually like working out in cooler rooms because I DON'T sweat as much. It's the only time I don't mind being in a cool room, as I am cold all the time, because I know in a couple minutes I won't be cold anymore, lol. Also, too warm a room makes me feel ill.
I'm on the "Eat-as-much-as-possible-while-still-losing-weight" diet. It's working.
Last edited by Tarisaande; 06-08-2010 at 01:44 PM.