REMEMBER gym class? The cold, noisy locker rooms with passels of teenagers "dressing out" for 35 or 40 minutes of frenzied activity; calesthenics led by whoever happened to be a varsity jock?

Remember the gym class games? Basketball with unlimited players on each team; one-minute wrestling matches, touch football featuring the near-adult types against the preadolescents?

And of course there was the dividing wall mystique - on the other side were members of the opposite sex. A peek brought shrieks and disappointment - gym suits were totally unflattering.

Things are different today, though gym suits haven't changed.

Title 9, the antisex bias law, and a recent emphasis on recreational ("lifetime") sports and elective classes have taken much of the dreariness out of gym class. In many Washington area high schools today enrollment is rising in physical education courses beyond those required for graduation. Many students now take phys ed because they like it.

Small wonder.

Every 4 1/2 weeks at Robinson Secondary School in Fairfax, phys ed students can choose from such activities as archery, racquetball, badminton, skiing, golf, gymnastics, basketball, soccer, volleyball, tennis. Last spring the school, in coordination with a private local swimming pool, taught swimming to 70 students who had littel or no swimming experience.

"Most people don't need team sports once they get a little older," said Ed Henry, phys ed chairman at Robinson. "We get kids more involved in lifetime sports and recreational activities now. They learn skills in sports they'll be using later in their lives."

But how is an individual-oriented sport like skiing taught for 4 1/2 weeks without snow?

"It wasn't too hard," said Barry Williams, who shared the teaching responsibilities in the ski course with Bob Menefee. "We waxed pieces of cardboard and had kids use them to get the feel of skiing. We simulated a chairlift and showed them how to get in and out of it - that can be very practical for beginning skiers."

Williams and Menefee also demonstrated basic ski equipment - proper jackets, bindings and boots. They showed films and had experts from ski shops as guest speakers.

The culmination of the course was an all-day trip to Ski Liberty in Pennsylvania where 168 students got to try out what they had learned.

"There wasn't one accident; everyone had a great time," said Williams, who took movies of the day on the slopes for use in this year's ski classes.

Last year Williams and Menefee also taught golf - coed, of course. Because Robinson has expansive grounds, Williams and Menefee were able to lay out a course with six 90 to 100-yard holes.

Williams, who is considering offering courses in camping, backpacking and fishing this spring, is sold on elective phys ed.

"It's definitely better than anything we had in the past," he said as he watched in-class racquetball competition. "There's more interest in the phys ed program because we're offering kids these programs and they choose whether to be in them or not."

Naturally, not all area schools are able or willing to offer the varied program Robinson offers. But even inner-city schools that lack the large campuses of suburban schools and such facilities as racquetball courts are altering their programs to provide coed electives.

At Eastern High in Washington traditional team sports are offered in addition to elective programs in gymnastics, fitness and individual sports. The electivies include tennis, golf, bowling, archery, table tennis and basketball over an 18-week period.

"We always try to provide some culminating event for each class," said department chairman Ed Jones. "As a class activity in tennis, we took everyone to Anacostia Park and played. After teaching bowling in school we all go to an alley. For the fitness class we take them to a local health spa.

"The culminating activity serves two purposes - it gives them something to look forward to and it also exposes them to recreational facilities available to them in the community."

The atmosphere in most gym classes today is as different from days past as the programs are. Title 9 toppled the dividing wall between sexes. Almost every sport offers girls and boys the opportunity to compete with one another.

Henry admits he had some difficulty feeling comfortable with coed phys ed after 20 years of working solely with boys. "Yeah, I used to baby the girls," Henry said as he spotted for a 10th grade girl flipping around on the uneven parallel bars in lgymnastics class."But now, hell, it's no problem."

In fact, the firls in Henry's gymnastics class are well versed in the art of razzing, once considered strictly a male jock specialty. As Henry gingerly mounted a trampoline to demonstrate a basic maneuver, one girl called out, "Cmon, coach, show us how to swivel our hips."

Immediately, three or four female voices picked up the chant, "Swivei hips! Swivel hips! Swivel hips!"

To be sure, at the ends of some high school gyms there are still all-male half-court basketball games going on while all girls are playing at the other end, but students have the option of coed participation if they want it.

At Lake Braddock High in Springfield, coed phys ed electives include a course which a decade ago might have been considered unthinkable - weight training. Today, phys ed teacher Rick Isaac splits a class into two equal groups. One group stays in the weight room to work out while the other group skips rope in an adjacent corridor.

A student goes to each of the 14 stations on a universal gym machine and any remaining students in the room prepare to do isometrics against the wall.

"Today we're going to do the torture circult," Isaac says. Groans ripple through the room. "Remember, the torture circuit means you use 10 pounds over what you'd normally use on the different exercises. I'll blow my whistle after 15 seconds, then you let the weight down and rotate to the next station."

Isaac blows his whistle, signaling the start. Weights clank; bodies strain. A make voice calls out, "Torture!" A red-headed girl with pierced ears strains to hold 100 pounds on the bench press. Next to her Robbie Hughes, a star running back who gained 1,100 yards in varsity football last season flushes while working the leg press. Another girl quivers from holding the weight she has curled.

Isaac's whistle sounds and the whole room exhales in relief.

"The turnout and the work in here has improved each year," Isaac says while the students rotate to new stations. "When I began the course two years ago the girls who signed up were reluctant to work hard. Now they work just as hard as the boys."

After every student has completed work at each station, including the "seat" drill, Isaac puts the second group through the same exercises.

It seems likely that a decade from now today's youngsters will remember gym class more happily than those of a decade ago. Perhaps Robinson's Barry Williams best sums up why:

"Today in phys ed classes we're giving kids the chance to do things they wouldn't get to do otherwise."