Passion for fitness and triathlons is helping fuel Jimmie Johnson's drive to be the best in NASCAR

Jimmie Johnson has won six NASCAR Sprint Cup season points championships and ranks at the top of his sport. But before he became the best race car driver, he was a high school swimmer and BMX cyclist, so he's loved being fit. Yet he never really tapped into his potential until he began training for triathlons a little more than three years ago. Now Johnson is in love with the sport and has big goals. But training and competing in triathlons is a tough thing to do with all his driving, family and business obligations. My story on J.J. for ESPN.com's Endurance Sports section: http://espn.go.com/sports/endurance/story/_/id/11199207/endurance-sports-triathlons-fitness-big-part-jimmie-johnson-success