Water in, sweat out: Finding a balance

There's a lot of conflicting information out there about how much water to drink every day. Some people swear by the 8x8 rule (eight 8-ounce glasses of water a day), while others say you should only drink when you're thirsty. The truth lies somewhere in the middle. Water needs are very individual and depend on things like your weight and activity level. The newest advice tells us that to know if we're drinking enough, we need to look in the toilet. If you can see your pee -- or if it's darker than a pale yellow -- it's time to drink up.

When you're exercising -- especially if you're exercising strenuously -- those hydration rules become even more important, and a little complicated. Fortunately, Women's Health has done a lot of research for you already. Take a look at what they have to say and find out if you're getting enough to drink, or if you need to refill that water bottle a little more often.

Speaking of water bottles, plastic is out. Here's a few of my favorite reusable water bottles for all of your fitness needs. (Pssst...they make great holiday gifts as well!)