Which one of the following does not contain calories?
a. protein
b. alcohol
c. water
d. carbohydrate

C. Water

It’s generally recommended that athletes consume approximately 30 percent of their daily calories. It is not at all the fixed amount of calories since different athletes playing in different type of games require different amount of calories. For those athletes that require more than 1 hour of continuous activity like the marathon runners, the amount of calorie required to consume far exceeds 30 percent. In case of normal games player activity normally does not continue for an hour. They do get breaks in the middle. 

Dthrough a slow process