Amped: A Soldier's Race for Gold in the Shadow of War

"When above-the-knee amputeeswalk, we generate seven to nine times the force of our body weight right into the point where the prosthesis meets our residual leg. For me, that's almost 1,500 pounds slamming into that socket."

For any amputee, learning to walk with a prosthetic leg is a painful, grueling ordeal. Soon after army medic Kortney Clemons, who lost his right leg to a roadside bomb in Baghdad, began the process, he had more than walking in mind. He wanted to run, and run fast. Barely...