Olympic athletes have to customize their diets to fit their sport, reports NPR. Swimmers like Michael Phelps can pound back 12,000 calories a day and go especially heavy on the pasta and bread before a race. But gymnasts and wrestlers stay away from heavy meals on the day of a competition, in order to stay nimble.
“Endurance athletes need the most calories because they are competing for hours, while basketball players go hard for a shorter period of time. Gymnasts, meanwhile, are stopping and going. Weight-lifters and shot putters harness a lot of energy for a very short burst. How much muscle mass each athlete has and their weight also affects how much energy they use,” says NPR, which offers a chart comparing the calorie intake of different types of Olympic athletes.