Spring sleepiness, summer fatigue, autumn nap, hibernation, all the year round is a good time to sleep.
Not only to sleep well at night, but also to take a comfortable nap at noon is a very happy thing. Siesta has always been a topic of great concern, and related topics have been on the hot search for many times: # Is it healthier to take a nap often than never? # # Is there a best time to take a nap? # # Healthy people should not take a nap for more than half an hour. While actively participating in the topic of sharing their nap stories,
netizens have developed some “nap anxiety”: from a scientific point of view, what is a healthy nap? What should I do if I can’t sleep for half an hour? What should I do if I don’t like to take a nap? Is it healthier to nap
often than never?
Indeed, there is a large body of research that shows that a healthy nap routine can bring many benefits, including but not limited to:
1. Reduced physical sleepiness;
2. Increased alertness and productivity;
3. Increased learning ability, creativity and memory; 4;
4. Alleviate brain aging and reduce the risk of cognitive impairment;
5. Reduce the risk of heart attack, heart failure or stroke;
6. Alleviate stress and improve mood;
7. Enhance the activity of immune cells and improve immunity.
However, not all people are suitable for taking a nap. In addition, the length of the nap, posture and other factors are also very important, if the sleep is not right, it may not be worth it.
1. People with insomnia should not take a nap. For insomniacs, because lack of sleep at night is often accompanied by excessive sleep during the day, once they take a nap, they are likely to sleep too long and not wake up, which will reduce the sleep pressure of insomniacs and aggravate the problem of insomnia. So for insomnia patients, even if they are sleepy during the day, they should stay away from the bed.
2. People over 65 years old with cardiovascular and cerebrovascular problems, obesity and other problems need to pay special attention to the length of sleep when taking a nap. This is because during the lunch break, the blood flow is relatively slow, and just after eating, the blood with high viscosity is easy to form thrombus on the blood vessel wall, which has the risk of inducing stroke.
3. Siesta position is also very important. If the sleeping position is not right, it is better not to sleep. Sleeping on the stomach and sleeping on the pillow and arm are the helpless choices of most students and working people. However, this sleeping position will make the muscles and ligaments of the cervical spine and waist in a state of excessive tension and traction, which can easily lead to cervical spondylosis. At the same time, this posture can easily lead to insufficient blood supply to the brain, resulting in more and more dizziness and tiredness. How long is a good
nap?
So, for people who are suitable for taking a nap, how long is the best time to sleep?
According to existing scientific research, the best time to take a nap is about 20 minutes for healthy adults. Because this stage is in the N1stage of the sleep cycle, that is, the light sleep stage, it is the easiest to wake up. When you sleep longer, you will enter deep sleep or rapid eye movement sleep, when you are forced to wake up, you may have fatigue, panic, or even persistent drowsiness and listlessness.
But not everyone has to abide by the 20-minute nap rule.
For example, there are significant differences in the needs of children of different ages for napping. The study, published in the Journal of the American Academy of Sleep Research, followed 172 children and analyzed their need for napping, and found that preschool children’s need for napping gradually decreased from 2.1 hours at the age of 3 to 1.6 hours at the age of 6. And interestingly, the researchers found that as children get older, they don’t actually need a nap every day, and not every child needs a nap. The researchers’ advice to preschoolers about how long their naps should last is to go with the flow.
With the growth of age, the demand for napping in the elderly is on the rise, and even some people who have not had the habit of napping may begin to nap as they grow older. This may be related to sleep disorders that occur with age. When sleep is insufficient at night, especially when deep sleep is reduced, it is easy to feel sleepy and nap during the day. A study of about 3000 people over the age of 65 showed that in three groups of 30, 60 and 90 minutes of napping, the elderly who took 60 minutes of napping had the best thinking and memory ability, while those who did not nap or took more than 60 minutes of napping had significantly lower cognitive levels.
In addition to age, the optimal length of a nap depends on the quality of the previous night’s sleep. For people who occasionally don’t get a good night’s sleep, a nap of less than 45 minutes can help them focus on the rest of their work. However, for people who often suffer from insomnia, it is not appropriate to make up for sleep at any time during the day.
In addition, a German study found that even a six-minute nap can improve memory. Because that’s enough time for the brain to convert short-term memory into long-term memory. So if you don’t have enough time, it’s also a good choice to recharge your body with 6 minutes of “fast sleep”.
You may also have heard that napping for more than hour increases the risk of cardiovascular disease by 34%, and that napping for more than hour increases the risk of Alzheimer’s disease by 40% in the elderly. It should be noted that many similar studies can only prove that long naps are associated with certain diseases, but the correlation does not represent causality.
That is to say, scientists have not yet fully proved whether the long nap time leads to the occurrence of the disease or whether the disease itself causes the increase in the need for the nap. However, these studies can remind us that when “half an hour of sleep is not enough” occurs for a long time, it is recommended to check the body and actively adjust sleep habits. It doesn’t matter if you can’t
sleep. Try to “wake up quietly”
. Some people may think that 20 to 30 minutes is too short to make people fall asleep, or that the alarm clock rings just a few minutes after falling asleep; There are also people who don’t have the habit of napping at all or don’t have the conditions for napping, so how can they make their brains healthier when these conditions occur?
Don’t worry, it’s not necessary to fall asleep. Closing your eyes can also have the effect of putting your brain to sleep. This state is also known as “Quiet Wakefulness”. In an interview, Dr. Rich Edward Brown (Ritchie Edward Brown) of
Harvard Medical School, who studies the sleep-wake cycle, showed that some electrical activity in the brain during quiet wakefulness is similar to that during sleep. This may be because when you close your eyes, you shut down the sensory input at the visual level, isolate some external stimuli, and with deep breathing to empty the brain, you can relieve stress, lower blood pressure and heart rate, and open the body’s rest mode.
A study has found that taking a nap with your eyes closed can have a similar positive effect on memory and learning ability. Another study, published in the journal Nature, found that when mice were in a “quiet awake” state, they sometimes zoned out and went into a “daydreaming” state, in which images appeared in their minds. In this process, the daydream images in the visual cortex and the playback activities in the hippocampus occur simultaneously, indicating that in the “quiet awake” state, the brain will actively activate the memory neurons in the past to learn and recover.
So, if you really can’t fall asleep at noon, you can rest with your eyes closed and let your thoughts drift away and be in a daze.
Author: Hardy
, Doctor of Neurobiology, Zhejiang University Reviewed by: Dong Xiaosong
, Chief Physician, Department of Respiratory and Sleep Medicine, Peking University People’s Hospital
