Siesta is also common in Southern Italy (there called riposo), where museums, churches and shops close during midday so that proprietors can go home for a long lunch and perhaps a snooze during the day’s hottest hours.
https://en.wikipedia.org/wiki/Siesta
Just 20 minutes is all you need to get the benefits of napping, such as improved alertness, enhanced performance, and a better mood. Naps of that length keep you in the lightest stage of non-REM sleep, making it easier for you to get up and go after your snooze session.
https://sleep.org/articles/how-long-to-nap/
If you are looking for deeper sleep rejuvenation: nap for 60 – 90 minutes. Final tip: When you take your shorter naps, sit up slightly, as it will allow you to avoid falling into a deeper sleep. If you dream during these power naps, it could be a sign that you are sleep deprived.
http://www.collective-evolution.com/2014/02/17/how-long-to-nap-for-the-biggest-brain-benefits/
According to Dr. Mednick, this is where longer naps of 60 minutes or so are said to be good for increasing that cognitive power again. [1] Mednick also states that the 90-minute nap will likely involve a full cycle of sleep, which aids creativity and emotional and procedural memory, such as learning how to ride a bike. Waking up after REM sleep usually means a minimal amount of sleep inertia.
http://www.collective-evolution.com/2014/02/17/how-long-to-nap-for-the-biggest-brain-benefits/
A study evaluating the recuperative effects of short and ultra short naps found that napping for 5-10 minutes can create a heightened sense of alertness and increase cognitive ability when compared to not taking a nap at all. If you are looking for a quick recharge: nap for 5 – 20 minutes.
http://www.collective-evolution.com/2014/02/17/how-long-to-nap-for-the-biggest-brain-benefits/
Researchers have found that a long nap -- of two hours or more -- can significantly improve alertness for up to 24 hours. Moreover, a preparatory nap counteracts the effects of sleep deprivation better than a nap taken after the missed sleep. 4. Put safety first.
http://www.huffingtonpost.com/2014/08/11/best-nap-napping-tips_n_5648651.html
Learn how many minutes to doze to feel happier and more alert. To nap or not to nap: That is the question! You may think that taking a catnap will make you feel more tired than skipping it altogether, but that’s not necessarily true. The key to waking up refreshed from a nap is all about timing.
https://sleep.org/articles/how-long-to-nap/
Time it right. Studies have tested a wide range of nap times, but for most individuals, it seems between 10 and 20 minutes of sleep is best. Longer naps can cause sleep inertia, or a period of grogginess and reduced performance caused by waking in the middle of deep sleep. 7. Get a wake-up call.
http://www.huffingtonpost.com/2014/08/11/best-nap-napping-tips_n_5648651.html
The brain is quite similar in that as you nap, even for very short periods of time, benefits can be seen in a number of areas. Sleep experts suggest that taking a 10-to-20-minute power nap can give you a quick burst of alterness and mental clarity when you don’t have much time.
http://www.collective-evolution.com/2014/02/17/how-long-to-nap-for-the-biggest-brain-benefits/
By Kelly Fitzpatrick for Life by DailyBurn. A mid-afternoon nap of just 10 minutes can help you stay alert for more than two hours when you're sleep deprived, according to research from the journal Sleep. But it's not just insomniacs who benefit from some midday Zzs.
http://www.huffingtonpost.com/2014/08/11/best-nap-napping-tips_n_5648651.html
how long is a nap ?
A nap is for 60 to 90 minutes. A nap is 60 to 90 minutes long.