The nitty-gritty about napping

Sleep is essential for your mind and body. It keeps you alert and focused. It helps cement memories. It may even boost your immune system, protecting you from illnesses such as diabetes and heart disease.

Given the many benefits of sleep, napping should be a no-brainer for better health, right? Unfortunately, the research shows mixed results. For instance, napping may relieve stress and improve alertness. It may also be good for your emotions. One study found napping may block negative feelings like frustration and impulsiveness.

But daytime napping may have a dark side. Some—but not all—past studies suggest napping may shorten your life. That may be especially true if you nap for more than 1 hour a day. One possible reason for this connection: People who nap more may have an undiagnosed health condition. Napping has been linked to diseases such as diabetes and depression. Or people who nap may simply not sleep well at night—a serious issue for your overall health.

Need some naptime?

More research is needed to fully decide if napping is a boon or a bust for your health. But it still may not be the best way to make up for lost slumber. Naps don’t give your body enough time in deep sleep. That’s the most restorative stage of sleeping.

Yet many people all over the world enjoy napping on a regular basis. For instance, siestas are a daily ritual in many countries. And experts advise naps for people who work the night shift, suffer from jet lag, or have a sleep disorder that causes them to fall asleep suddenly and unexpectedly (narcolepsy).

If you want to take a daytime nap, here are some tips to help you better catch that extra shut-eye:

• Limit your nap to 20 to 30 minutes. Longer naps can leave you groggy—a condition called sleep inertia. In such a state, you are more apt to make mistakes and have accidents shortly after waking up. But the groggy feeling usually doesn’t last longer than a half hour. Set an alarm to help limit your nap time. Stand up and move when you're done. This signals to the body that your nap is over.

• Don’t nap after 3 p.m. Naps later in the day may mess with your ability to fall asleep at night.

• Nap in a sleep-friendly environment. Choose a cool, quiet, comfortable place. Remove any bright lights, if possible. Just like at bedtime, limit distractions by turning off your cell phone, computer, and TV.