How Much Water Do You Need?

There was a time in the not-too-distant past where no one carried water bottles and yet people seemed to be just fine. Now we all pretend we have to cross the Mojave Desert just to get to work in our air-conditioned cars. A lot of this is marketing. Bottled water is big money, yet the purity of it isn’t all that different from municipal tap water. Plus, unless you are super-deconditioned, sweat is mostly water with minimal electrolyte content, so most people don’t need to hydrate with electrolyte solutions. If you’re worried about cramps, don’t be. The amount of calcium and magnesium you would need to lose to actually trigger muscle cramps is not something that occurs under normal conditions. Replacing magnesium won’t prevent them, nor will trying to ramp up your potassium by eating a banana. If you want to prevent muscle cramps, work on getting stronger, because they are likely to occur in a weak muscle that is put under more strain than it’s capable of handling. So what about hydration? In general, just trust your natural thirst mechanism, but if you really want to micromanage, see what your weight is on average first thing in the morning after you pee. Losing 2% or more of your body weight in water is when you’ll actually become symptomatic. If you can manage to keep your weight within one percent of your morning weight, you’re probably fine.