How much should I drink during a marathon or half marathon?
First of all, we recommend taking a drink to the start line and consuming 4-8 oz right before the gun goes off. This is your first water stop. Plan to consume 6-8 ounces of fluid every 2-3 miles or 25-30 minutes. For bigger races with aid stations every mile or two, one good rule of thumb is to just take fluid every time (so you don't have to think about it). A good strategy is to alternate sports drink and water. Pinch the top between your thumb and fingers, and you can nurse it for a few more yards. Most importantly, do not wait to consume fluids until you are "thirsty." At that point, you are already playing catch-up. Drink early, and when in doubt, choose the electrolyte replacement drink over water - then you'll get both the minerals and the H2O necessary for hydration.