Open-wheel race-car driver Alex Zanardi was within 13 laps of victory in Lausitz, Germany, in 2001, when he pulled out of a pit stop and fishtailed into 220-mph traffic. The force of a head-on hit to the cockpit's left side literally blew his legs off. When the former CART champ woke from a medically induced coma five days later, the first question he asked his wife wasn't "How am I going to live my life with no legs," Zanardi says, but, "How am I going to do all of the things I have to do with no legs?"

That drive and competitive spirit not only led Zanardi back into a race car just 18 months later but also propelled the 45-year-old Italian to the top of a whole other sport: competitive handcycling. This month, he'll be racing for gold at the Paralympics in London, favored among a field of athletes half his age.

Handcyclists race lightweight, three-wheeled bikes that operate via hand cranks. In Zanardi's competitive category, athletes typically ride trunk-powered cycles with low seat backs, which give the body a forward lean that forces riders to put their core into every crank. The sport requires tremendous strength and the use of smaller muscle groups that aren't meant to endure strain over long distances.

The sport – comprising sprints on tracks as well as longer distances on paved roads – has grown steadily in popularity since its development in the 1980s as a recreational activity and has been a Paralympic event since 2004. Zanardi had never considered trying it, however, until he decided to enter the New York City Marathon in 2007, just three weeks before the race.

Fired up to compete, Zanardi trained with a manic – and misguided – intensity. "I basically did 26 miles every day for 12 days," he says. "I had no idea what I was doing. I was overtraining." Still, he finished fourth in a field of 53, then returned last November and won.

These days, to prep for his event – the ­40-mile road race – Zanardi trains as thoughtfully as any other athlete headed to London. Before qualifying meets, he hits the gym five days a week, working his pecs, rotators, lats, biceps, forearms – all the upper-body muscles he needs to turn his cranks. For protein, he relies daily on an Italian staple, Grana Padano, a hard cheese whose origin dates back a thousand years. "I put a little orange jam on it, which is beautiful," says Zanardi, who lives an hour outside Venice with his wife, Daniela, and their 13-year-old son, Niccolò.

His star power in Italy today is bigger than anything he knew as a champion driver, even in F1-obsessed Europe, where he won dozens of races. He has to allow an extra hour for grocery runs "to talk to people and pose for cellphone photos."

While Zanardi's success is remarkable, it hasn't surprised former driving rivals all too familiar with his tenacity. "If Alex caught you, he had a way of committing," says ex-Indy car driver Bryan Herta, whom Zanardi famously outgunned on a risky corkscrew turn in a 1996 race in California. "It was like, 'I'm gonna make this pass, and I'm ­either gonna get by, or we're gonna have an accident.' He made you decide."

Today, flashes of Zanardi's generous spirit seem to temper his competitive zeal – he recently completed the Venice Marathon, towing an ALS-afflicted friend behind him the whole way. But hopeful opponents would do well to consider Zanardi's words to his team just before his first postaccident turn in a race car – on the same track where he'd crashed: "Listen, guys, I'm not gonna go out there and drive at parade speed. I'm gonna go for it."