Everyone understands the benefits of going to bed early and waking up early. But for many people, the day belongs to work, the night belongs to the family, only in the dead of night, time really belongs to them, and going to bed too early always feels lost......
If you can get enough sleep for seven or eight hours, is it feasible to go to bed late and wake up late?
"Life Times" (search for "LT0385" in WeChat to follow) combines medical research and expert views to tell you the answer and give you tips on how to get quality sleep.
Even if you get enough sleep, it is still not recommended to go to bed late and wake up late
What's the difference between sleeping at 10 o'clock and 6 o'clock and sleeping at 1 o'clock and 9 o'clock in the same 8 hours of sleep?
Theoretically, if you fall asleep and wake up at a fixed time each day, and the room is dark enough, there is not much difference between the two.
In fact, people who go to bed late often have disrupted sleep rhythms. Even if you get enough 8 hours of sleep, it is not recommended to go to bed late and wake up late, as evidenced by the following studies:
No.1
Going to bed late and waking up late increases the risk of diabetes
Recently, at the annual meeting of the European Association for the Study of Diabetes (EASD), Leiden University Medical Center in the Netherlands presented a new study: "night owls" who go to bed late and wake up late have a 46% higher risk of developing type 2 diabetes than people with a normal schedule.
According to the analysis of many experts, changing the circadian rhythm may affect the hormone system related to insulin sensitivity such as cortisol, ghrelin, and leptin, and sleeping late can easily lead to eating at night, which in turn increases the risk of diabetes.
In 2023, a paper published in the United States Journal of Internal Medicine gave a similar reminder: participants who went to bed late and woke up late had a 72% increased risk of developing type 2 diabetes compared to those who went to bed early and woke up early.
Researchers have found that going to bed late and waking up late can lead to an increase in behaviors such as poor eating and sitting for too long. After adjusting for bad behaviors, the correlation between going to bed and waking up late with diabetes decreased to 19%, but there was still a positive correlation.
No.2
May lead to "circadian rhythm misalignment"
A 2022 meta-analysis of 39 observational studies found that night owl sleep, which goes to bed later and wakes up early, was associated with an 18% increased risk of cancer, a 30% increased risk of diabetes, and an 86% increased risk of depression, compared with early bird sleep, which goes to bed early and wakes up early.
In addition, the patients who went to bed late and woke up late also had poor cardiometabolic indicators, and the levels of fasting blood glucose, glycosylated hemoglobin, and low-density lipoprotein cholesterol were higher than those who went to bed early and got up early.
The researchers pointed out that the reason may be related to the "circadian rhythm misalignment".
Circadian rhythm misalignment occurs when biological rhythms (e.g., sleep-wake cycle, thermoregulation, hormone secretion, metabolism, immune function, and cell cycle control) are out of sync with social activities (e.g., work, play) and physical environment (e.g., light), which in turn disrupts a range of physiological processes and increases the risk of disease.
No.3
Go to bed early and wake up early, not easy to be depressed
United States a study conducted by MIT and Harvard University found that each hour earlier in the midpoint of sleep (the midpoint between the time to fall asleep and the time to wake up) was associated with a 23% lower risk of major depressive disorder.
According to the researchers, the reason may be that the rhythmic activity of neurotransmitter systems involved in emotion regulation (such as dopamine, serotonin) has been affected.
The human body has its own "biological clock"
Zhang Bin, director of the Department of Psychiatry at Nanfang Hospital of Southern Medical University, said that sleep is greatly affected by the circadian rhythm system. Circadian rhythm is also the biological clock, abide by the biological clock, regular work and rest, in order to ensure healthy sleep.
From fast or slow heart rate to blood pressure fluctuations, from endocrine regulation to intestinal peristalsis, the rhythm of various physiological activities is affected by the biological clock. For example:
- heart rate, usually fast in the days and slow in the night, high in summer and low in winter;
- Blood pressure generally shows a trend of "high day and low night, two peaks and one valley", that is, it reaches a peak at 6~10 o'clock in the morning and 16~18 o'clock in the afternoon, and drops to a trough at 0~4 o'clock at night, forming a curve like a spoon;
- The intestinal motility rhythm is consistent with the body's diurnal activity, which is active during the day and weakened at night, so it is not recommended that everyone eat too much at dinner;
- The endocrine system generally fluctuates according to a certain cycle, such as the menstrual cycle, and the peak of cortisol secretion is early in the morning and drops to the lowest at midnight; Melatonin secretion increases at night and levels are low during the day, which helps the body fall asleep at night and wake up in the morning.
Ou Qiong, chief physician of the Sleep-disordered Breathing Center of Guangdong Provincial People's Hospital, reminded that there is currently insufficient evidence to support that people can delay falling asleep or reduce sleep time, and sleep still needs to be kept in a relatively constant and regular time frame.
Most people go to bed late because of sleep procrastination caused by playing with mobile phones, and they are not born "late sleepers", so if conditions allow, try to go to bed early and get up early to match the biological clock.
If you really need to go to bed late, how can you reduce the damage?
If you have to go to bed late, such as night shifts, jet lag caused by business trips, etc., other lifestyles should be a little healthier. Don't overeat when you go to bed at night, exercise regularly during the day, reduce sedentary times, eat a balanced diet, don't smoke and drink, maintain a healthy weight, and so on.
In addition, now that the sleep circadian rhythm has changed, adequate daytime rest is even more important. Usually adults sleep 7~8 hours a day.
Two principles of sleep that work for most people
The most intuitive test criteria for a good sleep are: comfortable body after waking up, full of energy, concentration, good memory, efficient work, and competent for any day's work and life.
There are currently two recognized influencing factors that regulate sleep, one is the biological clock, and the other is sleep self-balance. In layman's terms, the two key factors that affect sleep are "to be regular" and "to sleep enough".
How do you sleep regularly?
1. The bed is only used for sleeping, and do not do things unrelated to sleep in bed, such as playing with mobile phones and reading books. You can move around the living room first and wait until you're tired before going to bed, which can help develop the reflex between bed and sleep.
2. Try to get up regularly in the morning, even if it is a weekend, you should not get up too late.
3. Work hard to get rid of "obsessive-compulsive disorder to go to bed late", and think clearly before staying up late, whether playing with your mobile phone and chatting is worth the price you pay for premature aging and becoming ugly.
How do you get enough sleep?
Usually, children and adolescents sleep 8~10 hours a day; Adults sleep 7~8 hours a day; Brain metabolism slows down in the elderly, and they generally need to sleep for 5~7 hours.
1. Try to fall asleep before 11 p.m., and sleep delay should not become the norm.
2. If you are unable to self-adjust your insomnia, seek help from a doctor in time. Increasing sun exposure and physical activity during the day, covering a thicker quilt, quiet bedrooms, and curtains can help you fall asleep.
3. Try to calm the nervous system before going to bed, stop strenuous exercise, do stretching, soak your feet, stop the anxiety of "I can't sleep", and relax to fall asleep. ▲