The average adult only gets about six hours of sleep a night—two hours less than the recommended amount. And a lot of us get even less than that. The key to staying alert and functioning could be making up some of the deficit with a little midday shut-eye.
But in America's multi-tasking, double-caff, workaholic culture, sleeping during the day is often thought of as a sign of weakness. Even though a NASA study led by the University of Pennsylvania School of Medicine found that a 30 to 40 minute nap significantly increases alertness, reaction time and memory by up to 100%. Other studies have found that a 20 minute nap is more effective than a grande-sized Starbucks coffee or a bout of exercise.

Sleep is a foundational part of our biology, like diet and physical activity. And sometimes you need a little more. Naps have been found to curb the side effects of “temporary sleep deprivation.” Which means if you missed getting adequate sleep the night before, a quick nap can be restorative. Your job performance (and physical performance, in general) can also be enhanced by a brief period of shut eye. Quick power naps have been found to reduce stress and lower blood pressure as well. According to Dr. Sara Mednick, a leading sleep scientist and author of Take a Nap! Change Your Life, napping not only benefits your heart, but also boosts brain activity and speeds cell repair.
So don't fight the feeling when that familiar drowsiness hits you after lunch. Break up those long, busy days with a quick nap and return to the second part of your day as rested, refreshed and energetic as you were in the first. But there are few ground rules to keep in mind, to ensure you do it right. If you nap irresponsibly, you run the risk of feeling groggy all afternoon and messing up your next night’s sleep.
Do respect the nap window.
The prime nap time is 1 to 3 pm. This is when you naturally experience that midday dip in energy and concentration. If you give into the fatigue too late, you could affect your nighttime sleep quality.

Do set an alarm.
Dr. Michael Grandner, director of the Sleep and Health Research Program at the University of Arizona in Tucson says you want to aim for 15 to 45 minutes. “If you're otherwise well rested, that kind of nap can actually boost performance pretty well." So silence your phone and set your alarm. A 20 minute nap will increase alertness and motor skills; while 40 minutes will help boost your memory function.
The secret to falling asleep fast?
Close your eyes and concentrate on your breathing. Mentally whisper the words "in" and "out" with each deep breath. This will actually assist in pacing and relax you, allowing you to fall asleep fast.Try to darken your nap zone, or wear an eyeshade. Darkness stimulates melatonin, the sleep-inducing hormone.

Don't spring up when the alarm goes off.
Sleep inertia is a physiological state of impaired cognitive and sensory-motor performance that is present immediately after awakening. So open your eyes slowly, start wiggling your fingers and toes. Sit up and stretch. Within a minute you'll be awake and energized.