John J. Stein, neuroscientist, bike racer

"I had to throw out other hobbies to do this. I threw out fishing ... I figure I can always fish when I'm 90."

To perform his best, weekend bicycle racer John J. Stein puts more emphasis on his own physiology than the model or brand of his bike. The assistant professor of neuroscience is interested in the science of the exercise as much as he is interested in racing for competition and a workout.

"You can get very scientific about this if you try to understand what's going on," he said.

Stein, left, joined his wife and sister in a biking fund-raiser for diabetes in 1994 and hasn't stopped since.

During the racing season - April through September - Stein is either training on the bike or competing about four days a week. He enters distance races, ranging from 40 to 60 miles, and criterium races, which require riders to do laps around city blocks. But Stein, a Providence resident, takes to the suburbs to train, charting routes through towns such as Rehoboth, Smithfield and Lincoln.

When riding, he taps into what is going on in his body by using a heart-rate monitor attached to the handlebars. The monitor is positioned next to a speedometer, which tells him how fast he is moving and how far he has gone.

The monitor will indicate "if you are pushing too much," said Stein. Racers have their own lingo for that, terms like "hammering" which means going really hard, and "bonking," which is when a rider feels burning in the muscles and runs out of energy, he said.

The goal of training is to improve the muscles' ability to use oxygen, Stein said. Through training, a rider can achieve the short burst of energy to cross the finish line first or the endurance to pedal up the last length of a grueling hill.

In the two years since he began racing, Stein's training has paid off. He now competes at category four in amateur road races, which range according to ability from category five to category one - the best. Beyond the top amateur level are the professional races.

Competition has also taught Stein some racing tactics that revolve around teamwork: You use 20 percent less energy when you're riding behind someone because that person is breaking the wind, he said. "There is a lot of physiology behind this."

Throughout the winter, Stein keeps in shape by instructing a spinning course - an aerobic workout on stationary bicycles - at the Olney Margolies Athletic Center. He also belongs to the Brown Cycling Club, the group of faculty, staff and students who meet at the Faunce Arch several times a week and go on group rides.

"I had to throw out other hobbies to do this," said Stein. "I threw out fishing ... I figure I can always fish when I'm 90." - Kristen Cole