This might seem like a no-brainer, but even a muscle-friendly food like spinach is mostly water. So are you. That's why water is an essential part of any diet, but particularly if you're pumping iron.
Consider these benefits. Water aids in metabolism, keeps us from overheating, helps flush toxins and actually reduces appetite. In fact, drinking adequate amounts of water will actually reduce "water weight." That's because the body, when it's dehydrated, tends to store excess water.
Still, few of us -- including those who don't exercise regularly -- drink enough water, even without daily exercise. If you do work out, don't limit yourself to the 8 to 10 glasses of water daily recommended by the Dietary Guidelines for Americans. Instead, gulp another 12 to 16 ounces (3.4 to 4.5 deciliters) before hitting the gym, and 8 to 10 ounces (227 to 283 milliliters) for every 15 minutes of exercise to prevent dehydration [source: Robertson].