A little nap will do you...

Naps are a great way to recharge our brains and boost our energy, but we don't always have time for long siestas. Enter the researchers to tell us what science tells us.

Australian researchers studied twenty-four young adults who sleep well at night but don't normally nap. The participants napped for 5, 10, 20, and 30 minutes (plus a control of no napping) and then were measured across a range of benefits for three hours afterwards. The results:

The 5-minute nap produced few benefits in comparison with the no-nap control. 

The 10-minute nap produced immediate improvements in all outcome measures (including sleep latency, subjective sleepiness, fatigue, vigor, and cognitive performance), with some of these benefits maintained for as long as 155 minutes. 

The 20-minute nap was associated with improvements emerging 35 minutes after napping and lasting up to 125 minutes after napping. 

The 30-minute nap produced a period of impaired alertness and performance immediately after napping, indicative of sleep inertia, followed by improvements lasting up to 155 minutes after the nap. 

 A power nap of about 15 to 20 minutes is your best bet when you're feeling weary, but only if taken between 1:00 and 3:00 PM in the afternoon. Here's why. The longer you nap, the more likely you are to wake up from deep sleep, leading you to feel confused and groggy. [Also, i]f you sleep [too late in the day], the tendency would be to get into the first deep sleep of the night from which you would wake groggy and grouchy. Basically, you're not going to feel great post-nap if you end up in a deep sleep. You also risk the possibility of throwing off your circadian rhythm by entering that deep sleep or just sleeping at all too late in the day. While any sleep will improve your cognitive ability, it seems you can only sleep during the day without consequences if you time it just right.

While the perfect amount of time you should nap for may vary, if you're not sure how long to snooze or your naps just aren't cutting it, give the ten-minute power nap (also known as a nano nap) a try.