After Marine Capt. Eric McElvenny lost his leg in Afghanistan, he set his sights on a new mission: to become the fastest amputee Ironman triathlete ever

Eric McElvenny was a captain in the Marine Corps, doing his job in Afghanistan, when he stepped on an improvised explosive device. He lost a good portion of his right leg and wasn't certain what life would hold for him as a person with a disability. But McElvenny challenged himself to become a triathlete and has completed multiple Ironman and half Ironman races. Now he wants to break all records for speed in the sport. My story for ESPN.com's Endurance Sports section: http://espn.go.com/sports/endurance/story/_/id/12871240/endurance-sports-former-marine-eric-mcelvenny-lost-leg-became-ironman