Sleep health data

90% of indicators such as sleep duration, deep sleep proportion, number of nighttime awakenings, and other consumer electronic devices derived from "sleep score", "REM sleep compliance rate", and "sleep rhythm consistency" do not need to be taken too seriously, and there is no need to adjust your schedule in order to come up with good-looking numbers.

There have always been two completely different views on sleep data: one side is the "data refinement group" represented by consumer wearable device manufacturers, which advocates splitting sleep into dozens of dimensional indicators. The more detailed the indicators, the better they can reflect the problem and even help you adjust to the "optimal sleep state." A while ago, I helped my cousin who just started working look at her smart watch sleep report. In order to get a sleep score of 95, this girl set an alarm clock for 9:30 every day and forced herself to go to bed. Her mind was obviously still thinking about unfinished plans during the day. She lay with her eyes closed for two hours without falling asleep, but her score was even lower. In the end, she became nervous as soon as she went to bed, which almost led to bedtime anxiety.

Let’s talk about sleep duration first. There is really no need to stick to the general standard of 7-9 hours. Individual differences are so huge that you can’t imagine. I have a friend who is a screenwriter. He only sleeps 5 hours a day all year round. He doesn’t even need to drink coffee during the day. There are no problems in the physical examination. He is born a carrier of the short sleep gene. This kind of people accounts for 1%-3% of the total population. If you sleep 4-6 hours a day for more than a month, you are not sleepy at all during the day and can concentrate, then there is no need to force yourself to sleep more. But if you don’t sleep less than 6 hours a day for a week in a row and can take a nap while standing on the subway during the day, then even if your watch gives you a score of 100, you definitely don’t get enough sleep. Don’t kid yourself.

Oh, by the way, the ratio of deep sleep is the most controversial indicator. The reference value given by many devices is 20%-30%. I was fooled last year because my watch measured that the proportion of deep sleep was only 12% all year round. I was so scared that I went to the Sixth Hospital of Peking University for an overnight PSG monitoring. The result was that the actual proportion of deep sleep was 24%, which is completely within the normal range. The doctor who treated you said that consumer-grade devices rely on heart rate variability and body movements to determine deep sleep, and the error can be up to 40%. If you turn over or scratch an itch in the middle of the night, the device may directly put you into the light sleep stage, but in fact you may not wake up at all and are still in the deep sleep cycle. So for ordinary people, this indicator really doesn’t require a number. As long as you don’t feel sore all over the next day and feel as tired as if you had moved bricks all day, even if the watch shows that the proportion of deep sleep is only 15%, it is completely fine.

On the contrary, it is the number of night awakenings that many people do not take seriously, and the reference value is higher than the proportion of deep sleep. Many times you wake up for dozens of seconds in the middle of the night and can't remember it at all the next day. However, if you wake up unconsciously more than twice a night for a week, and each time lasts for more than 5 minutes, you need to find out the cause - either the temperature in the bedroom is too high, the quilt is too thick, or you are under too much pressure recently and your subconscious is always worried about things. If it is also accompanied by snoring and breathlessness, it is best to check whether there is a sleep apnea problem. Of course, there are also studies saying that occasional nighttime awakenings are a self-protection mechanism left over from human evolution. Primitive people should always pay attention to whether there are wild beasts attacking around them, so it is completely normal to wake up once or twice. Don’t start panicking as soon as you see incorrect data.

To be honest, I have seen too many people messing around in order to get good-looking sleep data. Some people take melatonin and endocrine disorders, some people buy thousands of dollars and are finally breathless, and some people adjust their biological clocks in order to synchronize with the so-called "optimal sleep rhythm." In the end, the data looks good, but the person becomes more tired. There is no such thing as perfect sleep data. In the final analysis, these numbers are just reminders, not test scores. Whether you feel comfortable sleeping or not and how energetic you are during the day are the core criteria. If you make yourself anxious as soon as you sleep because of a number, then you are really putting the cart before the horse.