Although Mindy Weisenberg is challenged by her job as a Middle-East policy researcher, she looks forward to the weekend when she can sit back and relax. Once Saturday rolls around, though, her leisure time is speckled with anxiety: She should write letters, take walks, be more active.

But that requires effort -- and effort means more work.

"I love the idea of sitting around and doing nothing," she says, adding that she enjoys getting up Saturday morning knowing she doesn't have to be at work. "But if I don't plan anything," she says, "I feel bored, anxious. I think about all the things that are stressing me out in my life. When I'm at work, I can block the world out."

Suggesting people like work more than play may seem outrageous, since most would argue their life is not that boring. But you've probably had dissatisfying weekends when you craved the return to a routine on Monday. Nothing can be sweeter than goals and deadlines after doing nothing productive for two days.

You are not alone. Many Washington professionals eagerly awaiting weekends don't know what to do when they leave their office, so they putt around their house, fret about their problems and pick fights with loved ones.

Studies measuring the quality of leisure time reveal that people are not having as much fun when they leave the office as everybody thinks. University of Chicago psychology professor Mihaly Csikszentmihalyi discovered that people are more satisfied when focusing on work than when drifting along with no plans during their "free time."

Nearly 110 people holding professional and blue-collar positions were asked to record in a booklet whether they felt alert, challenged or bored when an electronic pager went off at random from 8 a.m. to 10 p.m. They also were asked whether they preferred to be doing something else at that moment.

"When beeped at work, people felt creative, alert, and experienced satisfaction because they were confronted with challenges and had to use their skills," says Csikszentmihalyi in "Flow: The Psychology of Optimal Experience" (Harper & Row, due in paperback this fall).

Once the people left work their motivation plummeted. They reported feeling passive and dull while engaged in activities many might think are relaxing -- watching TV, eating out.

"We are supposed to hate work and love free time," says Tina Fellus, a District therapist, "but when people have a lot of free time, they think about their problems. If you aren't content with your thoughts, not having a lot of activities planned is scary."

There is nothing wrong with loafing around while lost in thought, adds Csikszentmihalyi, if people are engaged in "the purposeful discipline of problem-solving," aimed at resolving conflicts. But most people surveyed just dwelled on bad thoughts when not at their desks.

Although these people reported more satisfaction at work, they said they'd prefer not to be working. People, explains Csikszentmihalyi, believe the cultural stereotype that work is supposed to be an imposition, an infringement of freedom.

To achieve what Csikszentmihalyi calls "optimal experience" in their free time, people need to be challenged and do activities that demand skill and concentration. Reading, gardening, hiking, playing instruments or any other hobby will do, so long as people engaged in it set goals and evaluate progress.

Washingtonian Alice Rogers says she knew joining a volunteer literacy program would take some effort -- she'd have to sign up, undergo training, travel to meet her student. But Rogers, a newsletter editor who hustles to get stories before deadline, wanted to feel more productive when she left her Rosslyn office.

Home from work long before her boyfriend, Rogers used to stew over problems. "I got anxious when everybody else was still at work," she says. "I didn't feel I was a positive force in society." Teaching people to read, she says, makes her feel creative.

Harriet Ostroff of Rockville trained her kids to keep busy after school by engaging them in challenging activities. "We put together a family newspaper," says Ostroff, a librarian. "The kids wrote articles and had fun planning the headlines. We loved it."

Absorbed with her job at the library, Ostroff spends entire days thinking about books. At home, she sits before her PC, the TV droning in the background, and compiles a bibliography of specialized cookbooks. "I love to index, to classify things, to create order out of chaos."

When she reaches overload, Ostroff takes a breather. "I just sit and think, either about what I'm going to do or about the past," she says. But many people can't control their free time wisely and overbook their weekends without focusing on any activity. Such ambition is checked at work by colleagues, supervisors and budgets. But who is watching at home?

Joan Cavanaugh of Fairfax finds it tough to balance activities when she is not running development programs for an educational TV channel in Rosslyn. She makes plans on weeknights because the "idea of going home from work is too depressing.

"We apply the same pressure to leisure as we do to work," she says, adding her weekends are packed with aerobics, writing screenplays, meeting friends. "As a result, the expectation of life is so high it's ridiculous; you just can't keep up."

On the other hand, some professionals who make things happen at work don't feel they should have to put any effort into organizing their weekends. "People get sick of being motivated all week," says marketing consultant Ellie Schwartz of Silver Spring. "They don't want to do anything even though they know they could enrich themselves by doing cultural things like going to museums."

There is no reason people should be so wiped out from work that they can't pursue enjoyable hobbies, says Csikszentmihalyi. Leisure, he says, requires work, but people feel happier when they are doing something they like. "Relaxation goes up while watching TV," he says, "but afterwards people become much more tense. When you read or do a physical activity you enjoy, you continue to feel relaxed long after."

David Miller of Laurel decided to pump more energy into leisure when he got sick of being a couch potato, a status he says he enjoyed most of his life. After spending weekends with his wife doing "standard stuff" -- sitting around, driving around, watching reruns -- they bought bicycles and hit the trails.

"I'm happier doing something challenging," says Miller, a government computer programmer. "We both feel better about ourselves. It's relaxing to be riding because I don't think about any problems; I just focus on the physical aspect of it. When I go back to work on Monday, I feel creative and productive."

Miller was able to find a hobby he enjoyed. Others, overwhelmed by activities available in the area, have a tough time choosing, says Helen Epps, a psychologist in Arlington. "We suffer from a plethora of options," she says. "The activities cancel themselves out. People who are alone know there are things to do but they don't want to do them by themselves, so they get depressed during weekends."

In a related study, Csikszentmihalyi found that some working mothers welcome Mondays. "They wanted to forget about the reality of not being able to change things at home, because their husbands do this, kids do that. At work, they didn't care what happened or about the consequences, so it was more like play."

People who don't schedule anything until Sunday can rationalize not having plans Friday night because everybody is tired. Saturdays are devoted to chores -- laundry, haircuts -- but they start feeling tinges of anxiety as the eve approaches.

By Sunday noon, they begin to bite nails, tug their hair and yell at the cat. People surveyed in Csikszentmihalyi's study reported lowest moods on Sunday mornings between 10:30-12:30.

This depression is heightened by the dread of returning to work the next day without having had a fun weekend to share with colleagues. Inside, they probably feel relieved to go back to a schedule and hope that things look up next weekend.

Schwartz, who used to hate Sundays because, "You are told to rest even though nobody wants to," battled the Sunday blues. She started flipping through the newspapers for activities and recently dragged her husband to an art exhibit.

She hated the show, but they found wonderful sculptures in another part of the museum. They came home inspired and sketched the design of a home they'd like to build.

Psychologist Epps suggests people jot down activities that interest them over time: going to exhibits, taking a walk with their kids, practicing sketching. Whenever nothing comes to mind, she says, "Pull out the list."

"Jobs are easier to enjoy than free time," writes Csikszentmihalyi, because they have "built-in goals, feedback, rules and challenges." Similarly, people who build those conditions into leisure time, enhance the quality of their lives.

John Pomeranz of Arlington is in control of his leisure time. "The only difference between workdays and weekends is who I'm working for," says Pomeranz, a legislative representative for a Washington-based legal reform organization.

At work, he answers to his boss. At home, he is the boss.