Nutrition and fueling the body is really important,” Thomas says. “Under-fueled muscles will give out.”

Cox recommends fueling with carbohydrates and protein post-workout (he uses PowerBar protein bars and the ready to drink protein mix), eating a variety of vegetables and consuming plenty of water daily.

Keflezighi eats eat vegetables, salad, protein and carbs. His cheat foods are sweets. “I love cheesecake and tiramisu.” He also eats a PowerBar a couple hours after a workout.