It was the ultimate groan-and-roll-over morning -- but not for the 10 women touching noses to knees yesterday at Great Bodies.

At the Massachusetts Avenue NW exercise studio, they bounced on the carpeted floor, lifted their arms skyward and flung their legs toward the mirrored walls.

"Yes, I have a hangover," said Virginia Gilbert, a 23-year-old public relations specialist. "I felt rather light-headed when I first got up, but I'm much better now."

Nobody knows the bubbly we've seen, the goodies we've gorged, or the routines that we shot. But it's all over now.

For most people, yesterday was the final day to enjoy themselves before the holiday season receded into memory. Some chose to browse through the corridors of the Smithsonian Institution, the only government tourist attraction open on the holiday. Others stayed at home, transfixed by the five football bowl games on television. At Brookside Park Condominiums in Oxon Hill, a dozen residents gave their cars a first washing of the new year, and on Newport Place NW, some residents apparently spent part of the day dismantling Christmas decorations. Three abandoned trees waited by the curb.

For the area's first new parents of 1986 it was a day to savor their children for the first time -- as well as sudden fame.

At 12:01 a.m., a 5-pound 12-ounce boy, Tyrone Braxton, was born at Arlington Hospital to Gloria Braxton and Gerome Daniels of Alexandria. Because of their son's fortunate timing, the parents received free baby photos, a bib and six-months' free car seat rental from the hospital.

At Greater Southeast Community Hospital, an 8-pound 8-ounce girl was also born at 12:01 a.m. to first-time parents Toye Ford and Leslie McKenzie of Southeast Washington. The hospital served the mother a special dinner of filet mignon and sparkling fruit juice.

At the Hecht Co., one of the few area department stores open yesterday, there was the opportunity for more prosaic pursuits. A company official expressed surprise at the number of people who apparently still had some interest left in shopping. Not everybody, however, was drawn to the postholiday bargains. "We're both football fans, but I've had enough of it," said Tina Blackwell, who was browsing with a friend after brunch. "We're just killing time."

But today will be different; it presents the tantalizing clean slate, and marks the proverbial first day of the rest of our lives, the beginning of no-nonsense time. Break open the datebook, whip out the celery sticks, dazzle the boss, and let that erratic but ever-noble quest for perfection begin.

"I wanted to start the new year right," said Pam Frederick, a 30-year-old conference planner, explaining her willingness to do leg kicks at Great Bodies on the year's most notorious morning-after.

Starting the New Year right -- despite the fact that it has the poor grace to arrive in the middle of the work week -- is likely to be a major preoccupation in coming weeks.

Exercise classes are in hot demand. ("There's a lot of guilt out there," said Great Bodies owner Betsy Brown.) The area YMCAs are being rediscovered. ("They want to take advantage of the first two months to get over their holiday blues," said National Capital YMCA official Al Burris about his 6,000 members.) Area hypnotists such as Ted Garfinkle and Gary Hayman say they have new clients lined up, determined, by whatever method, to stop smoking or lose weight.

With the flick of a calendar page, everybody has A Goal. Or several.

"All year long, people decide they're going to do this or do that, but they don't get around to it," said Dr. Charles Sacks, a psychiatrist with offices in Greenbelt and McLean. "With the new year, which has become so ritualized, they have a chance to rededicate themselves. At least they have the illusion that this is a fresh start."

Besides, said Sacks, "What else are you going to do right now but buckle down?" After all, in January, the romance of Christmas snow and bracing peppermint winds gives way to the cabin fever of plain old winter. The next work or school holiday is many difficult mornings away. And, while Santa Claus may have come and gone already, the bulk of his bills has not yet arrived.

"Unfortunately, a lot of people are going to be very shocked when they get their Visa bills," said Hannah New of United Virginia Bank, which has about 250,000 credit-card customers. "We saw a lot of cash advances that far exceeded normal. We had to deal with a lot of calls right before Christmas from people wanting to get their credit extended. They seemed to think of it as free cash."

All in all, it's a fairly bleak picture, but the enterprising will find a way to sweeten the scene. For example, Frederick, after her vigorous workout, had specific plans for the rest of the morning. "I'm going directly to a brunch," she said, "to negate all the good I've done."

Sacks, on the other hand, has decided to postpone his personal pursuit of perfection. "I've got to start jogging again, but not this week," he said. "I'm not going to start until, say, March 1, how's that?"

And what about all those buy-now-pay-later types?

"Maybe they can enjoy all their lovely Christmas presents," said New, "while eating their hot dogs and beans."