Drowning at work? Maybe you should take a break and get moving. New research finds that busy professionals who exercise during the day feel more productive. They're also less likely to spout off at colleagues and slam down the phone after they've worked up a sweat.

British researchers studied about 200 workers at three sites: a university, a computer company and a life insurance firm. Workers were asked to complete questionnaires about their job performance and mood on days when they exercised at work and days when they didn't.

Participants were free to engage in the physical activity of their choice. Most of them spent 30 to 60 minutes at lunch doing everything from yoga and aerobics to strength training and playing pick-up games of basketball.

Six out of 10 workers said their time management skills, mental performance and ability to meet deadlines improved on days when they exercised. The amount of the overall performance boost was about 15 percent, according to the findings, which were presented this month at a meeting of the American College of Sports Medicine in Nashville, Tenn.

"The people who exercised went home feeling more satisfied with their day," says study author Jim McKenna, a professor of physical activity and health at Leeds Metropolitan University in the U.K.

"We were surprised," he says. "We weren't expecting this amount of effect." All of the study participants were regular exercisers and they already felt they did a good job at work. But many still saw an improvement with exercise.

Any exercise helped
The type of exercise didn't seem to matter. "We could find no difference according to length of exercise or duration or intensity," McKenna says. "You still got the effect no matter what you did."

Participants also rated their moods in the morning and afternoon. And as expected, exercise improved mood, a finding supported by other research, says McKenna. "There's a very strong mood effect with exercise," he says, adding that physical activity can be both energizing and tranquilizing.

During focus group discussions, many of the participants said exercise seemed to help them deal better with the demands and pressures on the job. "After exercise, people adopted a more tolerant attitude to themselves and to their work," says McKenna. "They were more tolerant of their own shortcomings and to those of others." They didn't lose their temper as much, for example, or yell at coworkers or slam the phone, he notes.

Workers in the study also indicated they were less likely to suffer bouts of afternoon fatigue known as the "post-lunch dip" on days when they exercised. "It's the paradox of exercise," says McKenna, "to get energy you have to expend some."

Dr. I-Min Lee, an associate professor of medicine at Harvard Medical School in Boston who studies the effects of exercise, says other research supports the notion that exercise might help people do their jobs better, perhaps by improving mood or easing stress.