I would say so. And even though it's congruent to your body weight, about a gallon, especially when bodybuilding and/or taking supplements, it's totally neccesary.
Exluding supplements, (meaning assuming you don't take any.) your body needs water. You probably sweat a lot more than what you realize, you lose it in urine and feces, and even when you exhale water vapor. Meaning you're losing body fluids. It also helps moisturize your skin. It's fuel for your body.
And even though there is *some* water in juices, you need straight water. Milk has no water, so that doesn't count.
If you want to break it down even more, water facilitates a lot of digestion in your body, causing chemical interactions, aiding metabolism.
If it makes you feel better, it hasn't been scientifically proven we need that much water. But the benefits are definetly there.
