How often do you take breaks at work? There is now research showing that office workers who take short, frequent breaks have more stamina and fewer aches and pains when they return to their desks.

Researchers from Baylor University surveyed employees between 22 and 67 years old over a five-day workweek.

They were not able to pinpoint the optimal number or length of breaks but found that timing is critical. The more hours that elapsed before a break, the less energized workers were when they returned, and the more symptoms like eyestrain and lower back pain they reported. In other words, working through much of the workday before taking a breather is not as helpful as taking time out early in the day.

After a morning break, employees said they had more energy, more motivation and were better able to concentrate. Breaks were particularly energizing if workers spent the time doing something they enjoyed.

The study doesn’t directly show that breaks increase productivity, but the researchers say it does show a link between taking breaks and higher job satisfaction; reduced emotional exhaustion; and greater willingness to undertake work above-and-beyond the minimum.