Video! NASCAR Superstar Jimmie Johnson's Workout Secrets

NASCAR champ Jimmie Johnson graces the May cover of Men’s Fitness magazine, in which he talks about what makes race car driving an endurance sport. He also shares what he found to be the most difficult part of training for his first triathlon last July.

Take a look!

To read more on Johnson’s workout methods, pick up the May issue of Men's Fitness, on newsstands April 22.