Grunt and push.

Strain, sweat, switch gears.

Long, lean muscular legs strapped in the pedals whirl past in a blur. Torsos decked in gaily-colored racing shirts crouch over the handlebars. Sweat drips from the leather helmet brow. Gears click in time to the rhythmic pump.

The final bell. One lap, 1.5 miles to the finish line. A dizzy light feeling. Arms held high. A big grin. The victory lap.

Shades of "Breaking Away."

The movie that had all America cheering has helped create a phenomenon. To bike is in, and so is bike racing. Washington cyclists have caught the fever. The biking boom is here.

From April through September, every Tuesday and Thursday at 6:30 p.m., Washington-area cyclists wind through the confines of the sprawling IBM complex in Bethesda and along the tree-sheltered road of Maryland's Greenbelt Park. Bikers of both sexes, all ages, novice riders to national champs, pedal anywhere from three to 25 miles. The bicycle training series are sponsored by Georgetown Cycle Sport and the College Park Bike Shop. Bike parts are awarded for prizes.

"People want to do more with their bikes than just take leisurely rides," explained Class A rider Larry Black, president of the National Capitol Velo Club, the largest racing club in the east. "They want to go faster, be competitive."

The first bike boom -- in 1973 -- was a byproduct of the gas crisis. The second jump came in mid-1979, following the release of "Breaking Away." The majority of bikes are no longer for children. Overall, the industry is up 15 percent from last year. NCVC's membership is up 275 from 50 a decade ago.

Competitive sport may attract the champion-caliber cyclist, but the pursuit of physical fitness is the motivating factor of most first-time riders.

"Biking somehow doesn't seen like exercise," said Leslie Roache, an IBM newcomer, "Everyone here has great bodies. I want to lose weight and have nice long muscles, not wide ones."

"I work a desk job in Columbia and wasn't getting any exercise," explained Ken Jacobson, 23, a Class C rider who races in both the IBM and Greenbelt series. "It's a great way to get in shape and it's an excellent outlet for pent-up energies."

"It was easy to get into the racing scene," said Steve Lindquist, 15, of Fairfax. "All my friends race; it's just a different pace from other sports."

Cynthia Paul, 16, a student at National Cathedral School, swam competitively before switching to bike racing two months ago. "My sister is an NCVC rider and one day I decided to give the bike a try." A natural athlete, Paul placed fifth at the National Open this year.

Before the days of organized races and local racing and touring clubs, Washington-area men -- no women raced then -- formed neighborhood racing groups and used the Lincoln Mall polo field and Hains Point for informal races.

So why the sudden surge in bike racing? Why the sudden scramble to the finish line?

"Celebrities like Eric and Beth Heiden (Olympic speed skaters) have done tremendous things for cycling," said Martha Rainey, 21, a student at the University of Maryland and one of the best women riders in the Washington area. "They've spotlighted the sport more than 'Breaking Away.' Whereas the movie was fantasy, the Heidens represent the realistic side of cycling. If Eric Heiden showed up here people would be cycling like crazy." c