Sleep health core information and explanations

It’s not at all the “you must sleep for 8 hours” as spread on the Internet, but Stability of sleep rhythm + matching of sleep quality with own needs , all the rest of the advice on sleep essentially revolves around these two cores.

Don't tell me, when I was doing sleep science popularization, I met too many people who were stuck in the "8-hour obsession" and couldn't get out. What impressed me the most was a girl who worked in Internet operations. In order to make up for 8 hours, she would lie in bed at 10:30 every day, staring at the ceiling even if she was not sleepy. If she worked overtime until 12 o'clock the day before, she would have to lie in bed until 8 o'clock the next day even if she woke up. , but the more she forced herself to sleep, the longer the sleep latency period became. Later, she went for a sleep monitor and found out that the actual sleep duration was more than 7 hours. She always felt that she was "unhealthy if she didn't sleep enough 8 hours." She became drowsy during the day, all thanks to the ice-American style.

In fact, there is no unified "standard answer" in the academic community regarding the recommendation of sleep duration. The 7-9 hours given by traditional sleep medicine for adults is the group average, but it really differs greatly among individuals. In 2009, a team from the University of California discovered that people with DEC2 gene mutations only need 4-5 hours of sleep a day to meet their physiological needs, without affecting their health and daytime status at all. The proportion of such people in the population is about 1%-3%. Maybe you are the colleague who stays up late every day and is still full of energy. On the other hand, some people are born with a need to sleep for 9-10 hours. If they sleep less than half an hour, they will be sluggish the next day. If they insist on sleeping for 8 hours, it is sleep deprivation.

So you see, there is really no point in worrying about how long you have slept. The standard for judging sleep standards is very simple: if you can be fully awake within 10 minutes after waking up, do not need to rely on coffee or energy drinks during the day, and will not doze uncontrollably in relaxing scenes such as long meetings or taking the subway, then your sleep is qualified. When I usually make adjustments to a client, the first step is never to ask him to change his schedule to shorten the sleep time. Instead, he keeps a sleep diary for three days, recording four points: how long it took him to lie in bed until he fell asleep, how many times he woke up at night, how long it took him to fall asleep again after waking up, and how energetic he was during the next day. These four indicators are more than 10 times more useful than counting the sleep duration with a stopwatch.

When it comes to insomnia, it is estimated that 90% of people have fallen into the trap of "the more they want to sleep, the less they can fall asleep". There are two completely different intervention ideas here. No one is right or wrong, only whether it is suitable or not: CBT-I (Cognitive Behavioral Therapy), the currently globally recognized first-line intervention program for insomnia, clearly states that if you don’t fall asleep after lying in bed for 20 minutes, you must get up and leave the bedroom and do something easy that doesn’t use your brain, such as flipping through two pages of a book or sitting on the sofa in a daze, and then go back to lie down when you feel sleepy to avoid forming the conditioned reflex of "lying in bed = anxiety and insomnia". However, some scholars who study anxiety disorders have suggested that for people who are prone to anxiety, forcing themselves to get up will actually aggravate the frustration of "I can't even sleep." It is better to lie on the bed and do progressive muscle relaxation or 478 breathing without putting pressure on yourself to "fall asleep." Even if you lie down with your eyes closed to relax, you can actually achieve a similar resting effect. A graduate student who was preparing for the exam came to me before and said that he used to use the CBT-I method to get up and memorize politics when he couldn't fall asleep. As a result, he became more energetic the more he memorized. Later, he switched to lying down for a body scan. Instead of forcing himself to sleep, he fell asleep in less than 20 minutes.

There is also a question that people ask a lot, "Is it good to catch up on sleep on weekends?" There was a lot of quarrel on the Internet before. Some people said that catching up on sleep will disrupt the rhythm and is equivalent to chronic suicide, and other times said that catching up on sleep can relieve sleep debt. In fact, both sides are reasonable. A 2022 study with 10 years of follow-up said that sleeping in on weekends every week and waking up more than 2 hours later than during the week will indeed increase the risk of type 2 diabetes and cardiovascular disease. Academics call this "social jet lag", which is equivalent to giving yourself two jet lags every week. But a new Swedish study in 2023 also mentioned that if you only stay up late a few times during the week, sleeping 1-2 hours more on weekends can offset part of the risk of cognitive decline caused by lack of sleep during the week, and there is no need to feel guilty. You just think, if you only sleep 5 hours a day during the week and force yourself to get up at 7 o'clock on weekends, isn't that going to be hard on yourself? As long as you don't sleep until two or three in the afternoon and wake up feeling dizzy and insomnia again at night, the extra sleep time will not have any impact at all.

By the way, by the way, I would like to mention the sleep monitoring bracelets and watches that are very popular right now. I generally recommend that you just watch them for fun and don’t be fooled by the “deep sleep ratio” mentioned above. At present, the accuracy rate of deep sleep monitoring of civilian wearable devices is generally less than 60%, and many of them are estimated by body movement and heart rate. I once had a visitor who clearly felt refreshed after a good sleep, but the bracelet said that his deep sleep was only 5%, and he became anxious and insomnia that night. You think this is not worth the loss.

In fact, after all, sleep is something that humans are born with. Just like eating when you are hungry and drinking water when you are thirsty, there is no need to have so many complicated rules and regulations. No sleep-aid aromatherapy, imported melatonin, or memory foam mattresses worth tens of thousands of dollars are as useful as getting up at a fixed time every day, not watching short videos while lying in bed, and drinking less than two cups of milk tea and coffee. After all, the way your body feels is always more reliable than those cold standards and data.