Even if you do not know anything about exercise or athletics, you know that staying hydrated, which means with enough water in your system, is important.
You see that all the time with runners at the New York City Marathon. But what about if you are not running a marathon? What should you during or after your workout?
We found Janine Pero at the Equinox Gym where she works out at least an hour every day. She has already run three marathons so she pays attention to hydration, which in her case, is unusual.
"I'm drinking coffee for the caffeine and then I'm drinking Crystal Light because I like the taste and there's no calories," said Pero.
While the caffeine in coffee may be a questionable choice for exercisers, and could be dangerous if you drink too much, there is no doubt that plain water is not.
In fact, plain water is fine for most exercise plans.
"Any exercise between 0 and 60 minutes, just drinking plain water is perfectly fine," said Kate Mone, a nutritionist from Cleveland Clinic.
However, it is when exercising more than an hour that a sports drink may be a good alternative.
That is because when you begin to sweat, you lose water. After about 60 minutes, you begin to lose electrolytes and sodium, and your glucose levels begin to drop.
Some sports drinks have now have added protein. However, so far there is no evidence that there is any added benefit in terms of energy or performance from the protein.
Then there are those labeled "energy drinks." Many of them are heavily loaded with caffeine, so it is best not to mix them with exercise.
One new area of research, however, is looking at a familiar drink for after the workout: fat free chocolate milk.
"There's been lots of research showing how chocolate milk is a perfect post-workout recovery drink because it has the exact, right combination of carbohydrate to protein to fat ratio that research shows will optimally refuel an athlete after their workout," said Mone.
Now these studies that chocolate milk will refuel post workout have not yet been reviewed by other experts. They were presented at the conference of the American College of Sports Medicine. However, the milk manufacturers funded them. That does not mean they are invalid, but do suggest the possibility of bias. But no calories, good nutrient - why not?