The stage was bulging with biceps, rock hard and flexed to please.

"That man has got muscles in his fingernails," gasped one woman in an udinece of 400 who paid $5 Saturday night to see 21 men compete for the title of Mr. D.C., and with it the bragging rights to the best built body in the metropolitan area.

The contest, held in Arlington's Washington-lee High School audditorium, was a male beauty pageant with a difference. None of the men who displayed their extraordinary forms under spotlights for a panel of seven judges was a natural beauty.

"You don't get this way without a lot of hurt," said Rusty davision, a 36-year-old College Park paper hanger who has been punishing his body with heavy wieghts and a spartan diet for the last three years to develop the kind of physique people will pay to see.

Body builders see themselves as sculptors, who mold their own bodies instead of clay. Not everybody, views then with such respect.

"There will always be people who sterotype us as homosexuals or muscleheads," said Paul Bleda, the owner of Tysons corner weight lifting gym and one of the judges at Saturday's contest. "But there are a lot more people today who understand our sport."

In the last five years, say area body builders, their ranks and the number of gyms that cater to them, have more than doubled. Weight lifting suddenly is chic.

"Five years ago body building was two or three standard deviations from the normal populace," daid Bleda, who owns a Ph.D. in psychology along with his gym. "Now the normal populace has moved a step or two closer to the body builders."

The sport got a massive dose of good publicity as a result of a book, "Pumping Iron," and a movie of the same name released in 1975. Both starred Arnold Schwarzenegger, the Austrian who completely dominated body building for six years, until he retired in 1976.

"Guys are literally making a living out of body building now," said Larry Hahula, a Springfield telephone installer and last year's Mr. D.C. who returned Saturday night to defend his title.

A more obvious change in the sport is the admission of women to the contests.

"We got tired of just handing out trophies or applauding in the audience," said Doris Barrilleaux, a 48-year-old grandmother from Tampa who flew into town to guest pose at the D.C. competition. "We're making it more of a family thing."

Barrilleaux was the only woman in Saturday's show and the oldest. Next in age was Essex Cook, a 40-year-old house painter from Washington who has been competing for 13 years.

"Let's face it, the fellas here look very good," said Cook, who was no 98-pound weakling himself. "But I just like to go up there against the youngsters."

Al Bedrosian, an 18-year-old freshman at Virginai Tech, was the youngest competitor and one of the crowd favorites. Everytime he struck a pose, his fans cheered as if he had doubled home the winning run.

The other competitiors, including a bus driver, a defense department analyst and a University of Maryland sophomore, had their own following in the audience.

"This crowd is great, they really got me up," said Marshall Gunter, a 29-year-old clerk in a Landover Mall shoe store, competing for the first time.

The judges apparently were not impressed by the applause. Three of the first place trophies, including Best Back and Best Legs went to Lou Mazzanotte, a balding, 5 foot 6, 154-pound research analyst for the Department of Defense who could have fit his vocal fans in a Volkswagen.

Larry Hahula retained his title as Mr. Super D.C. after a five-minute poseoff against this year's Mr. D.C. winner, Tony Cusack, that has the audience roaring.

When it was over, the competitors covered up up their body work with street clothes and mingled with the crowd in the lobby.

"I guess I don't know what to look for," said Laura Gubisch, 22, of Gaithersburg, who was not overly impressed with her first body building contest. "I was waiting for them to bring out Mr. Conviviality."