FOIRing Sleep Knowledge

1. Sleep time

(1) Standards for the duration of sleep at night
Ensuring adequate sleep every day is very beneficial to maintaining physical and mental health. The National Sleep Foundation of the United States recommends that the appropriate sleep duration for adults is 6-10 hours.
Studies have confirmed that there are "habitual long sleepers" (10 hours/day) and "habitual short sleepers" (<6 hours/day) in the population, so sleep time is not the only criterion for evaluating sleep quality. If the sleep time is lower than the recommended standard, don't worry too much. As long as you feel refreshed after waking up, it is not considered insomnia. In addition, prolonging sleep time does not necessarily make up for lack of sleep. Staying in bed for a long time is not conducive to getting high-quality sleep.
(2) Sleep structure
Sleep is divided into rapid eye movement (Rapid Eye Movement, REM) sleep and non-rapid eye movement (Non-REM, NREM) sleep, and NREM sleep includes light sleep and deep sleep. During sleep, REM sleep alternates with NREM sleep, and each alternation is called a sleep cycle. A normal person's whole night's sleep generally includes 4-6 sleep cycles, each cycle is about 90-100 minutes, and each cycle is not a simple repetition of the previous cycle. Generally, in later sleep cycles, REM sleep time increases and NREM sleep time decreases.
A typical sleep rhythm is a state transition in the following order: awakening-light sleep-deep sleep-light sleep-REM. However, in the actual sleep process, not all sleep states may be experienced, and the transition between sleep states may not be completely regular. For example, a person can go directly from any one of light sleep, deep sleep, and REM to wakefulness.

2. Deep sleep

(1) What is deep sleep

In the stage of deep sleep, the frequency of brain waves slows down significantly, and the breathing rate and blood pressure also decrease significantly, so deep sleep is also called slow wave sleep. People sleep the deepest during the deep sleep stage. If awakened during the deep sleep stage, symptoms such as dizziness, palpitations, and restlessness may occur. Studies have found that in the deep sleep stage, the brain can be fully rested, and the effect of eliminating fatigue is also the best. Deep sleep is extremely important for stabilizing emotions, balancing mentality, and restoring energy. Generally speaking, the longer the deep sleep time, the better the sleep quality. However, a long-term high proportion of deep sleep may be a signal of the onset of certain diseases, and it is recommended to seek the guidance of a professional doctor.

(2) How to have sufficient deep sleep?

According to the guidelines for the management of chronic insomnia in adults issued by the American College of Physicians (ACP), cognitive and behavioral therapy is recommended as the initial treatment for insomnia.

Clinical practice shows that chronic insomniacs usually have some bad sleep habits. If you want to improve sleep quality and alleviate the situation of excessive light sleep and insufficient deep sleep, you can refer to the following sleep improvement suggestions:

- Psychological factors: Excessive excitement, anxiety, mental tension, depression and other emotions may lead to increased light sleep and insufficient deep sleep. Generally, with the relief of these emotional reactions, sleep quality can be improved.

- Physiological factors: Excessive fatigue, physical discomfort caused by various diseases (such as pain, cancer itching, coughing, etc.) may lead to excessive light sleep and insufficient deep sleep.

- Environmental factors: Light, noise, temperature and humidity and other factors will interfere with sleep. Keep a quiet, comfortable, and dark bedroom environment. Choose suitable bedding, pillows, and mattresses to help improve excessive light sleep and insufficient deep sleep. Case.

- Rhythm of life: Factors such as shift work, jet lag, and irregular work and rest will disrupt the biological clock in the body, resulting in excessive light sleep and insufficient deep sleep. Rest regularly, go to bed on time, get up on time to welcome the sun, and let the biological clock run normally, which can improve the quality of sleep.

- Diet: Caffeine, nicotine, alcohol, and stimulant foods all have a disturbing effect on deep sleep, leading to excessive light sleep. Stay away from alcohol and tobacco, do not drink coffee or strong tea in the afternoon, and avoid eating and drinking at dinner.

- Exercise: Proper exercise increases the body's sense of fatigue, and the body needs to increase the time of deep sleep to eliminate fatigue, and the proportion of light sleep will decrease accordingly. However, strenuous exercise should be avoided before going to bed, otherwise excited limbs and high body temperature may make it difficult for you to fall asleep.

3. Light sleep

(1) What is light sleep?

During the light sleep stage, the electrical activity of the brain slows down, the heart rate and breathing rate slow down, and the person enters sleep but is easily awakened. Waking up from sleep is a protective mechanism and necessary for health and survival, so light sleep is also a normal physiological need. However, if the proportion of light sleep in the total sleep time is too high, the quality of sleep will deteriorate, and it is easy to feel sleepless and unable to recover from fatigue.

(2) How to improve the situation of excessive light sleep?

4. REM sleep

(1) What is REM sleep?

During rapid eye movement (REM) sleep, in which a person's eyeballs move rapidly back and forth under the eyelids, the vast majority of those awakened during this stage report dreaming. The awakening of rapid eye movement sleep is higher than that of light sleep and lower than that of deep sleep. At this stage, muscles are generally in a paralyzed state. This is a safety protection mechanism to prevent us from making movements in our dreams, which also explains why we often dream of not being able to run or scream.

(2) How to have normal REM sleep?

Maintaining a normal REM sleep schedule is important for mental health, boosting creativity and relieving stress. Research has shown that subjects who were deprived of REM sleep became irritable, tense, and easily fatigued. Dreams mainly occur in the rapid eye movement sleep stage, and a high proportion of rapid eye movement sleep may be manifested as dreaminess. Many people mistake dreaminess as the cause of poor sleep quality. In fact, it is because of not sleeping deeply, which makes it easy to remember dreams when waking up. When REM sleep is lacking, our bodies automatically make up for it by extending REM sleep over the next few nights, so there's no need to worry too much. If the long-term rapid eye movement ratio is too high or too low, accompanied by symptoms such as irritability and anxiety, it is recommended to seek the guidance of a professional doctor.

If you want to have normal REM sleep, you can refer to the following sleep improvement suggestions:

- Life pattern: Generally speaking, in the sleep cycle in the second half of the night, the REM sleep time is longer. If you feel that you have more dreams, it is recommended that you adjust your work and rest time, go to bed early and wake up early.

- Psychological factors: Avoid excessive anxiety and fatigue, relieve stress in work and life in time, and help maintain a normal REM sleep time ratio.

- Diet: Caffeine, alcohol, nicotine or medications may have an effect on REM sleep resulting in a low REM sleep rate.

5. Sleep awakening

(1) Awakening at night

The causes of awakenings during nighttime sleep are complex, ranging from very brief micro-awakenings to longer-lasting awakenings. People may not be able to realize all the waking ups, and the "seemingly awake" state of love may be related to sleep disorders, too little or too much sleep and other factors. Under normal circumstances, the number of awakenings during night sleep is less than 2 times, and the total awakening time does not exceed 10% of the total sleep time. If you wake up frequently at night, you may be an insomniac who has trouble maintaining sleep. The proportion of deep sleep in this group of people is usually significantly lower than that of normal people. Even if the total sleep time does not decrease, there will be poor physical recovery after waking up.

(2) How to improve the sleeping party and easy to wake up?

If you often wake up during nighttime sleep, or find it difficult to fall asleep after waking up, accompanied by symptoms such as fatigue, anxiety, and irritability, you can refer to the following sleep improvement suggestions to analyze and find the reason for waking up easily, and make targeted adjustments in time.

- Cultivate regular living habits and strengthen the body's circadian rhythm. Go to bed on time, and wake up at the same time the next day, regardless of whether you slept well or not. Receive sufficient sunlight during the day, avoid long naps during the day, and never take a nap as soon as you are tired.

- Avoid high-intensity mental activities before going to bed, do not watch TV, play with mobile phones, watch tense TV programs in bed, and do not bring problems to bed to think about. Before going to bed, you should relax your mind, calm your emotions, and don't think too much.

- If you wake up during the night, don't be overly anxious, don't check the time too often, relax and trust that you will fall asleep again.

- The environment in the bedroom should be comfortable, the temperature should be suitable, and noise and bright light should be avoided.

- Maintaining regular moderate-intensity exercise (such as brisk walking, jogging) can promote sleep at night when body temperature rises during exercise. However, strenuous exercise should be avoided before going to bed, otherwise excited limbs and high body temperature may make it difficult for you to fall asleep.

6. Nap

(1) Nap duration standard

If you don't get enough or low-quality sleep at night, you can replenish your energy with appropriate naps during the day. In general, taking a 15-30 minute nap before 1:00 p.m. can re-energize you and improve your wakefulness and productivity in the afternoon.

However, daytime naps should not exceed 45 minutes, otherwise you may enter a deep sleep stage, your body temperature will drop, and you will feel very sleepy after waking up, or you may experience adverse symptoms such as dizziness and nausea. At the same time, if you enter a deep sleep during the day, it will reduce your sleepiness at night, making it difficult to fall asleep at night.

(2) What time is suitable for daytime naps?

The most important part of the biological clock is the body temperature rhythm. When the body temperature rises, people will feel more awake; when the body temperature drops, people will feel tired and sleepy. Body temperature fluctuates periodically throughout the day, rising in the morning, sometimes dropping in the middle of the day, and continuing to rise until nightfall. Therefore, it is best to take a nap when the body temperature drops at noon (generally before 1:00 noon). Naps too late during the day can interfere with body temperature rhythms and affect nighttime sleep quality.

*A single sleep of less than 1 hour is counted as sporadic naps.