Hydration and Exercise: How to Get It Right
Drink before and during exercise
Clark recommends drinking fluids before you even begin to exercise, especially if you’re doing something that requires a lot of stamina. "You need to start drinking about one and a one half to two hours before running a marathon," she says.
Also, drinking fluids during a workout isn’t a bad idea either. "We don’t drink enough during exercise and that puts you in a hole when you finish and then you have to rehydrate," says Clark. "It’s better if you don’t put yourself in that hole in the first place."
While it might be cumbersome to carry water with you on a run, it’s worth it, she says.