How far will the stretch stretch?

That is the question being asked about the stretch-fabric, body-conscious clothing showing up in several designer collections for spring.

Body clothes started as something to wear while exercising, but the fashionably fit have been wearing them for 10 years or so. They've chosen totally body conscious stretch suits from Norma Kamali and Giorgio Sant-Angelo - suits those designers have worked into complete costumes - or they've chosen Danskin leotards and Isotoner outfits to team up with their own best-fitting skirts or pants.

Now, in a season when body-conscious clothing had begun to move in on full-blown styles that blur the figure outline, more designers have worked up body clothes in stretch fabrics.

Close to 20 years ago California designer Rudi Gernreich, once a dancer himself, said that clothes in the 21st century were likely to be like dancers leotards; men and women would simply decorate their tights with jewelry. Even Geoffrey Beene, the New York designer with a penchant for elegant, loose-fitting clothes emphasizing comfort, believes the future in clothing rests with scientific changes in fabric.

"Buck Rogers cartoon clothing is not unlikely or far off," he projected. "It may be like second skin that you decorate as you please." He says he is currently on the track of thermal control clothing. "The next clothing revolution will come from the chemists," he insists.

For the last year or so many Washingtonians have been wearing Danskins and skirts as disco garb.

But no one here, as far as we know, has carried it quite as far as the New Yorker who had designer Betsey Johnson do a stretch body suit wedding dress and a black stretch suit for the disco party afterward.

From left: a green padded shoulder jacket and pink stretch pants with a strap under each foot, by Marion Kop; a Danskin red shirred leotard with bareback and black stretch jeans, by Beaujangles; a pink skirt and body suit, by Betsey Johnson; a pink-and-black striped body suit and pants, by Betsey Johnson; and a black stretch strapless flounce top with brandy-colored straight skirt and fingerless gloves, by Norman Kamali OMO.