How long should I nap? Why 20 to 30 minutes is best, and longer naps can leave you more tired

• A short nap of 20 to 30 minutes can improve mood, sharpen focus, and reduce fatigue.
• If you nap for longer than 30 minutes, you may find yourself feeling more groggy and fatigued.
• However, naps should not replace the recommended 7 to 8 hours of sleep.

If you're feeling exhausted and irritable towards the middle of the day, a short nap may be exactly what you need.

In fact, taking a few naps each week may even be good for your long-term health. But not all naps make for a better day, and they should not replace the recommended seven to eight hours of sleep each night.

Here's what you need to know about when napping can benefit your health and the best strategies for taking a productive nap.

You should nap for about 20 to 30 minutes

"A short nap of 20 to 30 minutes can often be a healthy alternative to drinking more coffee," says Alex Dimitriu, MD, a psychiatrist and founder of Menlo Park Psychiatry & Sleep Medicine.

In fact, getting about 30 minutes of sleep can put you in a better mood and improve your memory. According to Dimitriu, napping for this short amount of time will also improve symptoms of fatigue such as irritability, low motivation, and sleepiness.

In a 2016 study, researchers observed the effects of napping on study participants. Those who napped for 30 minutes exhibited improved mood, while naps of 10 minutes or less were associated with worsened mood.

Longer naps aren't as effective

Taking a nap for too long or too late in the afternoon could make it harder for you to get high-quality sleep at night.

A nap late in the day may have the benefit of reducing your fatigue at the moment, but it could also make you feel less sleepy and make it harder to drift off to sleep at bedtime.

And if you nap for longer than 30 minutes, you may find yourself feeling more groggy and fatigued than you did before. This is called sleep inertia.

"This happens because after more than 30 minutes, our sleep becomes deeper, and it can be harder to get going again after that," says Dimitriu. That deep sleep is known as slow-wave sleep and it follows several minutes of REM, or lighter sleep.

If you feel the need to nap several times a week, you probably aren't getting enough sleep each night. "Napping should be the exception, not the rule, ideally with a focus on optimal nighttime sleep of 7 to 8 hours," says Dimitriu.

Tips to take a healthy, productive nap

In order to properly address fatigue and mental fog, here are the best ways to take a healthy and refreshing nap:

• Sleep for 20 to 30 minutes. Any longer could leave you feeling worse or disrupt your nighttime sleep, Dimitriu says. To get to sleep quickly, turn off the notifications on your phone and set an alarm for 30 minutes. If you can't fall asleep, try going for a walk or another strategy to boost energy levels.
• Nap early. Try not to nap after 3 p.m., as doing so can disrupt with the sleep you need at night-time. Ideally, you should take a short nap towards the middle of the day.
• Draw the blinds and check the thermostat. Creating a comfortable and quiet environment will help you get good rest. Your room should be as dark as you can manage during the day, and at a cool temperature. Turn on white noise or a sound machine if there are loud disturbances keeping you from sleeping.
• Don't rely on naps. While the occasional nap can be healthy and even have long-term benefits, don't overdo it. For example, research has found that napping up to twice a week is associated with reduced risk of cardiovascular events. But more frequent napping doesn't help, and if it harms your sleep at night, you may be at a higher risk for heart disease.

Insider's takeaway

Naps that last 20 to 30 minutes can be refreshing, but if you sleep longer than that you may wake up feeling groggy. If you aren't getting enough high-quality sleep at night and often feel the need to nap, you may also have an underlying health issue, and you should talk with your doctor about sleeping habits.

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