Although he's been a professional cyclist for seven years and has worn the vaunted yellow jersey as a leader of the Tour de France, Dave Zabriskie is no less vulnerable to that bane of every cyclist, from amateurs to pros: cars.  

Five years ago, while riding down a canyon road in Utah on a training run, Zabriskie was clipped by an S.U.V. He was flung from his bike and onto the hard pavement. The left side of his body was immobile. Later at the hospital, pins were inserted into his left wrist and leg; doctors doubted he'd ever ride again.

"I underwent painful rehabilitation just to walk again, let alone ride a bike," says the 29-year-old.

By the following year, Zabriskie was leader of the pack once again. During a stage of the Tour of Spain, he made a risky breakaway and pulled ahead by almost 100 miles. "I had no idea whether or not I could pull it off," Zabriskie recalls. "Toward the end of the stage, I was vomiting [because] I was digging so deep."

Zabriskie has since become one of the premier time-trial cyclists in the world, specializing in those race stages during which cyclists compete individually against the clock. In the first stage of the 2005 Tour de France, he set a record for the fastest time trial ever in that race, with an average speed of more than 34 miles per hour over the 12-mile length of the course, narrowly edging Lance Armstrong. Zabriskie has also won a stage at the Tour of Italy, making him the only American to have ever won individual stages at each of the three grand tours of Europe. Not even the legendary Armstrong pulled off that particular feat.

In a strange twist of fate, his accident made him a better cyclist—he became more focused on avoiding injury than ever before. "When I starting racing and was moving through the ranks, I found myself breaking away and time-trialing to the finish line to avoid crashes," he says.

Zabriskie began riding seriously in high school when a teacher who noticed his interest in biking suggested he join a local cycling club in Salt Lake City. The club introduced him to longer rides and competitions, and Zabriskie eventually won a race that qualified him to live and train at the U.S. Olympic Training Center in Colorado Springs. He then qualified to become a member of the national team and began his international racing career. He now races between 70 to 90 days a year, and trains almost every day, sometimes up to seven hours a day.

The cyclist recently switched team affiliations from the powerful Team CSC squad to the newer and lesser-known Slipstream-Chipotle, in part because of its rigorous emphasis on drug testing (each of the team's riders has agreed to be tested 1,200 times throughout the season, 20 times more often than required of other professional cyclists).

As for compensation, Zabriskie says that although professional cyclists can earn a pretty good living, the pay pales in comparison to what pros in other sports make.

"Most cyclists don't make as much in salary as a golfer makes in prize money for one event," Zabriskie says. "Why couldn't I be a golfer?"