These 3 types of people are really not suitable for naps! Check if it’s you

Spring sleepiness, summer fatigue, autumn naps, and winter hibernation are all good times to sleep.

It is not only important to sleep well at night, but also to take a comfortable nap at noon. Napping has always been a topic of great concern to everyone, and related topics have been on the hot search list many times: #Is it healthier to take a nap frequently than never taking a nap#, #Is there an optimal length for nap#, #It is best for healthy people to take a nap for no more than half an hour# ...

While netizens actively participated in the topic and shared their own nap stories, they also developed some "nap anxiety": From a scientific point of view, what kind of nap is considered healthy? What if half an hour is not enough sleep? What if you are born not to like naps?

Picture from Weibo Hot Search

Taking naps frequently is better than never taking naps

Healthier?

There is indeed a large amount of research showing that healthy napping habits can indeed bring many benefits , including but not limited to:

1. Reduce the body's sleepiness;

2. Improve alertness and work efficiency;

3. Improve learning ability, creativity and memory;

4. Alleviate brain aging and reduce the risk of cognitive impairment;

5. Reduce the risk of heart attack, heart failure or stroke;

6. Relieve stress and improve mood;

7. Enhance the activity of immune cells and improve immunity.

However, not all people are suitable for taking naps. In addition, factors such as nap duration and posture are also very important. If you sleep incorrectly, it may not be worth the loss.

1. People with insomnia should not take naps. For people with insomnia, because of insufficient sleep at night, they often sleep too much 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 insomnia problem. Therefore, for insomniacs, 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 during naps. This is because during the lunch break, the blood flow is relatively slow, and the blood with high viscosity is easy to form blood clots on the blood vessel walls, which may induce the risk of stroke.

3. Nap posture is also very important. If you don’t sleep in the right posture, it’s better not to sleep at all. Sleeping on your stomach or with your arms as pillow is the helpless choice of most students and office workers. However, this sleeping posture will make the muscles and ligaments of the cervical spine and waist in a state of excessive tension and stretching, which can easily cause cervical spondylosis. At the same time, this posture can easily lead to insufficient blood supply to the brain, causing you to feel more dizzy and tired the more you sleep.

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How long is the best nap?

So for people who are suitable for taking naps, how long is the most appropriate time to sleep?
According to existing scientific research, the best nap time for healthy adults is about 20 minutes. This is because this stage is in the N1 stage of the sleep cycle, which is the light sleep stage and is easiest to wake up. When sleeping longer, you will enter deep sleep or rapid eye movement sleep. If you are forced to wake up at this time, you may feel tired, flustered, or even persistently drowsy and listless.

But not everyone has to follow the 20-minute nap rule.
For example, there are significant differences in the need for naps among children of different ages. A paper published in the American Sleep Research Society tracked 172 children and analyzed their nap needs. The results showed that as they age, the need for naps in preschool children gradually decreases 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 they get older, children don’t actually need a nap every day, and at the same time, not every child needs a nap. As for the length of naps for preschool children, the researchers recommend that nature take its course.

As people age, their need for naps actually increases. Some people who did not have the habit of taking naps may even start taking naps as they age. This may be related to sleep disorders that occur with age. When people do not get enough sleep at night, especially when they have less deep sleep, they will be more likely to feel sleepy and take naps during the day. A study covering about 3,000 people over the age of 65 showed that among the three groups of naps of 30, 60, and 90 minutes, the elderly who took a 60-minute nap had the best thinking and memory abilities. The cognitive levels of the elderly who did not take a nap or took a nap for more than 60 minutes were significantly lower than those of the former.

In addition to age factors, the optimal length of a nap depends on the quality of sleep the night before. For people who occasionally don't sleep well at night, a nap of less than 45 minutes can help them concentrate on subsequent work. However, for people who often suffer from insomnia, it is not advisable to make up for sleep at any time during the day.

In addition, a German study found that even a 6-minute nap can improve memory. This is because this period of time is enough for the brain to convert short-term memory into long-term memory. So if time is insufficient, using a 6-minute "quick sleep" to recharge the body is also a good choice!

You may have also heard some sayings like: napping for more than an hour will increase the risk of cardiovascular disease by 34%, and the risk of Alzheimer's disease in the elderly who nap for more than an hour will increase by 40%. It should be noted that many similar studies can only prove that napping for too long is related to certain diseases, but correlation does not mean causality.

In other words, scientists have not yet fully proved whether it is the long nap that causes the disease or the disease itself that causes the increased need for naps. However, these studies can still remind us that if we find that "a half-hour nap is not enough" for a long time, it is recommended to check our body and take the initiative to adjust our sleeping habits.

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It's okay if you can't sleep

Try Quiet Sobriety

Some people may think that 20 to 30 minutes is too short, not enough for people to fall asleep, or the alarm clock rings just a few minutes after they fall asleep; some people have no habit of taking a nap or do not have the conditions to take a nap. So, when these situations occur, how can we make our brains healthier?

Don’t worry, you don’t necessarily have to fall asleep. Closing your eyes and resting your mind can also give your brain a nap. This state is also called “Quiet Wakefulness.”

Dr. Ritchie Edward Brown, who studies the sleep-wake cycle at Harvard Medical School, once said in an interview that in a quiet awake state, some of the brain's electrical activities are similar to those in sleep. This may be because closing your eyes shuts off visual sensory input, isolating some external stimuli, and deep breathing to empty your brain can relieve stress, lower blood pressure and heart rate, and turn on the body's rest mode.

Not only are the EEG activities similar, a study found that closing your eyes and resting can also have a positive effect similar to a nap in improving memory and learning ability.

Another study published in Nature found that when mice were in a state of "quiet wakefulness," they would sometimes lose focus and enter a state of "daydreaming," with images appearing in their minds. In this process, the daydreaming images in the visual cortex and the playback activity in the hippocampus occurred simultaneously, indicating that when in a state of "quiet wakefulness," the brain would actively activate past memory neurons for learning and review.

Therefore, if you really cannot fall asleep at noon, you can still rest by closing your eyes and letting your thoughts drift away or daydreaming.

Planning and production

Author: Hardy, PhD in Neurobiology, Zhejiang University

Reviewer: Dong Xiaosong, Chief Physician, Department of Respiratory and Sleep Medicine, Peking University People’s Hospital

Planning丨Zhong Yanping

Editor: Zhong Yanping

Proofread by Xu Lailinlin