Proper hydration during exercise and before competition isn't easy. Too little, and you can overheat, dehydrate, and do serious damage to yourself. Too much, and you can get ill, or even suffer from hyponatremia, a sometimes fatal condition. We talked to the experts to help you do it just right.
Calculate your sweat rate.
To know how much you should hydrate during a specific athletic activity, you first need to know how much you sweat during that activity. Calculating sweat rate is a fairly simple process. First, do some brief warm-up exercise to begin perspiring, then weigh yourself naked on a scale. Perform the exercise activity at the normal intensity for an hour, drinking a measured amount of fluids when you feel thirsty. After the hour, weigh yourself again. Subtract your post-workout weight from your pre-workout weight, and convert the lost weight to grams (one pound is about 454 grams). Add the amount of fluids consumed (in milliliters; 1 ounce is about 30 ml) to that figure, and this final amount is the number of milliliters you should drink per hour to remain adequately hydrated.
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