It’s a rare thing indeed when something fun also happens to be good for you. Fried food, alcohol, sitting in front of the TV for long stretches at a time — all fun, all not so healthy. But the universe, perhaps as an apology for all the overlap between the things we love and the things that slowly kill us, has thrown humankind one small bone.
Napping, as it turns out, is pretty great for the body and mind, in addition to just being great. A 2007 Harvard study, for example, found that people who napped regularly — at least half an hour, at least three times a week — had a significantly lower risk of heart disease, and separate studies have shown that a 40-minute nap during the workday can improve on-the-job performance for both astronauts and doctors.
But with napping, as with all things, there’s a right way to do it, and there’s a wrong way. A recent feature in New Scientist offered a few tips for optimal napping, starting with the timing: If you have an hour to spare, opt for a longer snooze, which does different things for the brain than a less substantial sleep session.
Longer naps — around an hour to an hour and a half — allow for deeper sleep, which is better for strengthening memory and helping you retain information, Matthew Walker, a psychology professor at the University of California, Berkeley, told New Scientist. But if you just don’t have that kind of time, even short naps have their cognitive perks: “There are wonderful little champagne-cork bursts of electrical activity that happen during light sleep, called sleep spindles,” Walker said. “And the field of sleep research is rapidly seeing that they have learning and memory benefits.” Even six quick minutes of shut-eye have been down to make a difference.
And the time of day, Walker explained, matters just as much as how long you lie down for:
During the night, each 90-minute sleep cycle includes a bout of non-REM sleep followed by REM sleep. However, deep non-REM sleep tends to dominate in the first half of the night, with the balance then shifting to REM sleep. A morning nap is much more likely to contain REM sleep, says Walker, “because your brain still has a preferential hunger for it.. In the afternoon and evening that changes. So, morning naps are likely to contain more emotionally calming dream sleep and afternoon naps more restorative and memory-boosting deep sleep.
Regardless of when you take your nap, though, make sure to do it lying down (if you can swing it — not all workplaces are so friendly to the under-the-desk blanket nest). In one small 2010 study, volunteers who caught a few winks in a bed were more alert post-nap than those who had slept sitting up in a chair, though both groups were more awake than the people who hadn’t napped at all.
Of course, nothing is without its warts, and there’s a downside to napping: “sleep inertia,” the grogginess you often feel right after waking up. As we transition from sleeping to waking states, it takes our brains a little while to crank up to their normal cognitive capacity; most of the time, though, this state only lasts between a few minutes and half an hour. Possibly shorter, if you have coffee on hand.
Which brings us to the most glorious nap of all, the caffeine nap. Some research has suggested that drinking a caffeinated beverage immediately before a quick nap will leave the napper feeling more refreshed than either the drink or the sleep by itself. Sounds like all the permission you need to pour yourself a cup of coffee and curl up in bed — after all, it’s for your health.