Biathlon may be the toughest endurance sport in the Olympics. After grueling circuits of Nordic skiing, athletes have to calm their breathing, steady their tired legs and shoot tiny targets with a rifle.
Andy Soule does it all with only his arms.
"It's a steep learning curve, learning to sit-ski," says Soule, a member of the U.S. Paralympic team. He's strapped into a seat attached to two fixed cross-country skis. He speeds along the course by hauling himself with ski poles.
Soule, who will begin the Paralympic biathlon competition Saturday in Sochi, Russia, lost his legs to a roadside bomb in Afghanistan while deployed with the U.S. Army in 2005. He tried a few different sports as part of his rehab, and in 2007, on a whim, he borrowed a rifle and tried a biathlon race.
"I hit two of my 10 shots, maybe very shaky," he recalls with a laugh.
Shaky or not, Soule caught the attention of Team USA, and at the 2010 Vancouver Paralympics became the only American ever to win a medal in biathlon in either the Paralympics or the able-bodied games.
Soule is modest about his medal and his marksmanship; he was also rated an expert with a rifle during his Army career.
He's not the only American in the Paralympics who learned to shoot in the military. Another is Dan Cnossen, who is still active duty in the Navy.
"I wanted to move and shoot like I used to," he says.
Cnossen was leading a Navy SEAL platoon in Afghanistan when a bomb cost him both his legs in 2009. The damage was severe and recovery was tough. At first, all he could focus on was improving a little each day.
"At one point, improvement was sitting up out of bed because I hadn't for weeks and my balance was all gone," he says. "They had to hold me and let go and I'd fall back down. But I always focus on the next steps, and the next thing you know, I'm running."
Cnossen started running on prosthetic blades, then tried skiing and then made the U.S. team for Sochi. The advantage for a Navy SEAL like Cnossen is that he has the skills to ski his fastest right up to the target range and then calm down quickly and shoot.
Other military habits don't help. In combat, Cnossen says, he needed to be aware of everything around him. At the biathlon, that's all distraction.
"I'm so aware of other skiers, people cheering, the announcer talking I need to tune that out, but it's hard," he says. "You just have to focus on those five shots, on that little black circle."
Of course, Cnossen would still rather be leading Navy SEALs. But for sports, he says, the biathlon might be as close as it gets.
"I can move and shoot. I can be on a team," he says. "I can travel, train hard for a goal seems like a pretty good transition."