Is Drinking to Drury a Good Strategy for Marathon Running?

Dr. Hydration: Drinking to thirst is a good approach for survival, but it's not an effective strategy in the long run. He says if you wait to get thirsty or guide your drinking based on thirst, you're also running the risk of over-drinking. Dr. Hydration advises that athletes design what they really need to drink during exercise and test themselves with a body scale.