For many people, napping is a guilty pleasure. But if you’re age 65 or older, a new study suggests that an afternoon nap may benefit your brain.

The researchers looked at about 3,000 Chinese adults, ages 65 and older. They found that those who had taken an hour-long nap after lunch did better on cognitive tests than those who did not nap or took a shorter or longer nap.

“This study shows that a nap after lunch may be part of a healthy lifestyle for older adults, whereas naps at other times of day might affect nighttime sleep,” says Manisha Parulekar, M.D., of Hackensack University Medical Center.