Calories: 0 per 8 oz.
Electrolytes: No
Carbohydrates: No
Caffeine: No
Protein: No
The Science Says: Hydrate pre-exercise with 2 to 3 cups, 2 to 3 hours before exercising. If you’re working out less than 60 minutes drink 3⁄4 to 11⁄2 cups every 15 to 20 minutes.
What It's Best For: Zero calories and free, water should be your everyday go-to.