Gasp!

On the bad days, the best swimmer in the U.S. just tries to stay afloat. When the air grows thin, the walls close in and those familiar black spots spin around in his head, Tom Dolan doesn't think' about setting records or winning medals. He only hopes to reach the end of the pool before losing consciousness.

At times Dolan, the world-record holder in the 400-meter individual medley, is forced by the effects of his exercise-induced asthma—effects exacerbated by the unusual narrowness of his windpipe, which allows him only 20% of the oxygen intake of the average person—to cling to the lane ropes, like some frantic shipwreck survivor, as everything goes dark. "I always make it to the side of the pool," says Dolan, "although sometimes I'm not sure how."

At the U.S. Olympic Trials in Indianapolis in March, Dolan overcame both his breathing difficulties and a case of chronic fatigue to win three events. He arrives in Atlanta as the U.S. swimmer with the best shot at winning a gold medal in each of several individual events; he's the clear favorite in the 400 IM and one of the favorites in the 200 IM and the 400 freestyle. If all goes well, Dolan could emerge as a star of the Games, for his personality as well as for his medals. Who says swimmers are about as much fun as water in the ear? Dolan is an outgoing, earring-wearing, rap music aficionado who, when he is not gasping for air, is usually laughing or smiling or talking a blue streak.

Dolan has learned to live with his asthma, and his coaches have learned to keep an inhaler by the edge of the pool to revive him when he passes out during one of his maniacal workouts. Lots of athletes will tell you they train until they drop. Dolan means it.

"That is one thing that worries me," says Tom's father, Bill. "I tell him, 'You must have certain sensations before you pass out. I want you to recognize them and stop swimming before it happens.' Hey, it's great to have the fire and the desire, but I also want him to have a little common sense."

The 20-year-old Dolan never has had much use for common sense. It just gets in the way. The truth is, if he didn't swim competitively, he might not even have known he had asthma, which in his case is induced solely by exertion. But the way Dolan sees it, his breathing difficulties, which arise only in training sessions, actually benefit him by making him work harder than his rivals do. "Every day I'm in the pool, I know I'm getting more out of it than if I were able to breathe normally," he says. "So there's a bright side to it. It definitely increases my tolerance for pain and forces me to endure a little more than anyone else."

Some swimmers are born with great lungs; Dolan had to settle for everything else. He is as long and lean as an eel. He stands 6'6", weighs 180 and has 3% body fat. His arms stretch to hands that look like canoe paddles, and if his feet (size 14) were any bigger, they could be classified as flippers. In the water Dolan covers 50 meters with an awesome combination of grace and power, the way Julius Erving finished a fast break. The mere mortal in the next lane is often left to wonder, What's the use? "I never worry about who's around me in the pool," says Dolan. "I know if I do what I can do, nobody is going to be next to me at the end."

Indeed, swimming has always seemed to come more naturally to Dolan than breathing. He learned the sport at age five at a country club in his hometown of Arlington, Va. At 15, he won three titles at the junior nationals and made the senior nationals in three events. In 1994, when he was 18 and the youngest male member of the U.S. team, he set the world record in the 400 IM while winning the event at the world championships in Rome.

Dolan, who will enter his senior year at Michigan next fall, has already completed a dazzling college swimming career. In his three seasons of competition—he has given up his final season of eligibility to pursue endorsements—he set three U.S. records and was twice named NCAA swimmer of the year.

"And he's only going to get better," says Rick Curl, coach of the Washington, D.C.-based Curl-Burke swim club, to which Dolan has belonged since he was 14. "A lot of swimmers burn out after a while, but I don't see a hint of Tom being tired of the competition. He just hates to lose so much. We came up with an expression to describe his attitude. We call it 'zero-flat.' That's Tom's goal. Once he records a time of zero-flat, he'll hang up the suit."