Drink enough water, but it is a little more complicated than that.
During and after most physical activity, it doesn’t matter whether you drink water or sports drinks as long as you drink something to replace fluids.
For rehydration after short periods of routine exercise, water is fine.
After extended periods of exercise or exertion, sports drinks containing carbohydrates and electrolytes help prevent dehydration and restore important minerals that are lost when you sweat.
There is some supporting evidence that electrolyte/carbohydrate formulas may enhance performance, endurance and recovery, particularly for the elite/endurance athlete and after long-term strenuous
activity, such as marathons and full triathlons.
If you drink too much water, there is the hazard of “water intoxication” and hyponatremia (low blood sodium)