Can you drink too much water?

Yes. It is possible to drink too much during exercise. If you gain weight by the end of a training session or competitive event, it is a sign you drank too much water or other fluid during your activity. Drinking too much could result in excess water in the blood and a dangerously low sodium concentration. This condition is known as hyponatremia. Although it is rare, hyponatremia can be fatal; reinforcing the importance of drinking proper amounts of fluid, as opposed to trying to drink as much as possible.

Hydration