How to follow the Chinese body clock for better sleep? Have you ever had this experience: even though you’ve had a full eight hours’ sleep, you still wake up feeling completely drained? Or, come three or four in the afternoon, your mind feels as though it’s been filled with lead and you simply can’t think straight?
The problem may not lie in ‘how long you sleep’, but rather in ‘when you sleep’.
The 2017 Nobel Prize in Physiology or Medicine was awarded to three American scientists whose research unveiled the molecular mechanisms of the ‘biological clock’—the human body does indeed possess a precise circadian rhythm system that regulates almost all physiological activities, including sleep, metabolism and hormone secretion. In its citation, the Nobel Committee specifically noted: ‘Their discoveries have helped us understand how plants, animals and humans adapt to circadian rhythms.’
Interestingly, as early as more than two thousand years ago, our ancient forebears had already fully grasped this phenomenon—the theory of ‘Zi-Wu Liu-Zhu’ (the flow of qi through the meridians at specific hours) proposed in the Huangdi Neijing divides the day into twelve shichen (time periods), with each period corresponding to a specific meridian in charge; qi and blood circulate through the body according to these periods, which is almost entirely consistent with the ‘biological clock’ studied in the Nobel Prize-winning research.
The Ling Shu section of the Huangdi Neijing records: ‘The meridians flow ceaselessly, in harmony with the heavens and in unison with the earth.’ This means that the circulation of qi and blood in the human body is synchronised with the natural rhythms of heaven and earth. Today, following this ancient yet scientific ‘Chinese body clock’, we shall clarify what one should and should not do at different times of the day.
I. Nourishing Yin in the Middle of the Night: the hours of Zi, Chou and Yin (23:00–05:00)
This period is the prime time for the body to ‘recharge’. If you miss it, no amount of catching up on sleep during the day will make up for it.
During the hour of Zi (23:00–01:00), the Gallbladder Meridian is dominant. The Huangdi Neijing states: ‘All eleven viscera depend on the gallbladder. ’ Only when the energy of the gallbladder is generated can it drive the organs throughout the body to commence their daily functions. One must fall asleep before 11.00 pm for the Gallbladder Meridian to function smoothly. Dr Ding Xiaoying of Shenzhen Traditional Chinese Medicine Hospital points out: ‘Those who fall asleep before the Zi hour wake up with a clear mind, high spirits and a rosy complexion.’ Put simply, ‘the clearer the gallbladder, the clearer the mind’.
Chou Hour (1:00–3:00) is when the Liver Meridian is active. The Huangdi Neijing: Suwen explains this clearly: ‘When a person sleeps, the blood returns to the liver.’ You must be in a deep sleep at this time for the liver to complete its tasks of storing blood and detoxifying the body. If you are still scrolling through your mobile or binge-watching dramas at this hour, the liver blood cannot return—and the next day, you will be left with a sallow complexion, dry eyes and a short temper.
The Hour of the Tiger (3:00–5:00) is governed by the Lung Meridian. The lungs govern the body’s qi; at this time, qi and blood transition from yin to yang and are redistributed throughout the body. If you frequently wake up inexplicably at three or four in the morning, it is likely a sign of deficient lung qi. Lie still quietly; do not get up abruptly to move about—as ‘the lungs govern the hundred vessels’, deep sleep during this hour is crucial.
A follow-up study of 116,000 people published in the Journal of the American Medical Association found that people who habitually fall asleep in the early hours of the morning have a more than 25 per cent higher risk of cardiovascular disease than those who fall asleep at a normal time. It is not simply a matter of getting enough sleep; sleeping at the right time is the key.
Stop saying ‘if you don’t sleep at night, you can catch up during the day’—the Zi-Wu flow won’t wait for you; once it’s gone, it’s gone.
II. Cleansing and Nourishing the Stomach in the Early Morning: the hours of Mao, Chen and Si (5:00 – 11:00)
As dawn breaks, it is time for the body to ‘boot up’. If you get this phase right, you will maintain good energy levels throughout the day.
During the hour of Mao (5:00–7:00), the Large Intestine Meridian is active. The large intestine is the body’s ‘main artery’ for detoxification. Upon waking, start by drinking a glass of warm water—no need for much, 200–300 millilitres is sufficient—to gently awaken the intestines and help establish a healthy habit of having a bowel movement first thing in the morning. Experts at Shenzhen Traditional Chinese Medicine Hospital advise that developing a regular bowel routine is particularly important for those suffering from chronic constipation.
During the Chen hour (7:00–9:00), the Stomach Meridian is dominant. This is the time of day when the body’s ability to digest and absorb nutrients is at its peak. After an overnight fast, gastric acid secretion is at its highest, making this the ideal time for the body to accept breakfast. The *Huangdi Neijing* (The Yellow Emperor’s Classic of Internal Medicine) refers to the stomach as ‘the sea of water and grain, the great source of the six fu organs’, whilst later medical scholars went so far as to state that ‘the stomach is the foundation of postnatal life’.
However, there are certain considerations when it comes to breakfast—it should be warm, soft and nutritionally balanced. A bowl of millet porridge with an egg, or a portion of steamed sweet potato with a cup of soya milk, are both far more beneficial than cold milk with dry bread. The Chinese Nutrition Society explicitly states in the *Chinese Dietary Guidelines (2022)* that the energy provided by breakfast should account for 25–30 per cent of the total daily energy intake, and that skipping breakfast significantly increases the risk of gallstones, obesity and type 2 diabetes.
During the Si hour (9:00–11:00), the Spleen Meridian is at its peak. The spleen governs transformation and transport, and is responsible for delivering the nutrients from breakfast to the entire body. Li Dongyuan, one of the Four Great Physicians of the Jin-Yuan period, once said a phrase that has been passed down for nearly a thousand years: ‘Injure the spleen and stomach internally, and a hundred diseases will arise.’ At this time of day, the greatest taboo is—sitting for prolonged periods. The *Huangdi Neijing* states that ‘prolonged sitting damages the flesh’, and as the spleen governs the muscles, this is how the saying ‘prolonged sitting damages the spleen’ originated. After sitting for over an hour, stand up and move around for a few minutes—stretch your limbs and walk up the stairs—to get your spleen energy flowing.
A cohort study of 34,000 people conducted by the National Institute of Health and Nutrition in Japan revealed that among those who skip breakfast, the incidence of metabolic syndrome is 18–25 per cent higher than among those who eat breakfast regularly.
Eating a good breakfast is the best investment you can make for your stomach and digestion that day.
III. Nourishing the Heart and Promoting Metabolism During the Day: the hours of Wu, Wei and Shen (11:00 – 17:00)
During the Wu hour (11:00–13:00), the Heart Meridian is at its peak. The heart is known as the ‘sovereign organ’; this hour marks a crucial juncture in the transformation of the vital energy of heaven and earth, and is also the time of day when yang energy is at its zenith. It is best to finish lunch before half past twelve, followed by a 15–30-minute nap—even closing your eyes for a few minutes to rest your mind is better than pushing through on empty.
A study published by the European Society of Cardiology in 2020 indicated that people who take a nap once or twice a week have a 48 per cent lower incidence of cardiovascular events than those who never nap. However, it is important to note that naps should not exceed 40 minutes; sleeping for too long can actually leave you feeling more tired. If possible, avoid sleeping face-down to relieve pressure on your cervical spine and eyes.
The Hour of the Goat (13:00–15:00) is when the Small Intestine Meridian is active. The small intestine is responsible for separating the useful from the waste—absorbing essential nutrients into the bloodstream whilst expelling waste products. If you eat a lunch that is too greasy or eat too quickly, your small intestine will have to work extra hard. After lunch, it’s a good idea to take a leisurely stroll to aid digestion; don’t sit back down straight away.
Shen Hour (15:00–17:00): The Bladder Meridian is active. This is the second peak period of the day for learning and work efficiency. The Bladder Meridian runs along the back and is known as the body’s largest detoxification channel. Drinking plenty of water at this time (around 500 millilitres) helps promote smooth urination and flush out internal heat. Experts at Shenzhen Traditional Chinese Medicine Hospital issue a special reminder: under no circumstances should you hold in your urine! Holding in urine not only damages the bladder but also increases the risk of urinary tract infections; doing so over the long term is a silent killer of kidney function.
The Huangdi Neijing states: ‘The bladder is the official of the capital; bodily fluids are stored therein, and when transformed by qi, they are expelled.’ Only when you have drunk enough water and urination is unimpeded are the body’s channels for eliminating waste truly unblocked.
A half-hour nap and drinking plenty of water in the afternoon are the two simplest and most effective things you can do at this time of day.
IV. Evening: Consolidation and Calming of the Mind – You, Xu and Hai hours (17:00–23:00)
During the You hour (17:00–19:00), the Kidney Meridian is dominant. The kidneys govern the storage of essence and are the foundation of one’s innate constitution. At this time, the body enters a ‘consolidation and storage’ mode; strenuous exercise and overeating are not advisable. Some people like to go for a brisk 5-kilometre run after work—but no, this hour is better suited to gentler activities: taking a stroll, doing some stretching, or brewing a cup of warm goji berry tea, allowing the kidneys to quietly complete their daily task of storing the day’s essence.
⛔ Things to avoid during the Hour of You：High-intensity exercise, cold showers, and gulping down icy drinks—all of these disrupt the Kidney Meridian’s rhythm of storage, and doing so over the long term can easily deplete kidney qi.
During the Hour of Xu (19:00–21:00), the Pericardium Meridian is dominant. The pericardium acts as the heart’s ‘outer guardian’, specifically protecting the heart from invasion by external pathogens. The *Huangdi Neijing* states: ‘The Shanzhong is the minister and servant; joy and pleasure arise from it’ — maintaining a cheerful disposition at this time is the best way to care for the heart. You might chat with family, listen to some light music, or take a few deep breaths. Simple stretches and a gentle stroll are both beneficial, but be sure to avoid extreme emotional swings.
During the Hour of Hai (21:00–23:00), the Triple Energizer Meridian (TE) takes charge. The Triple Energizer governs the five internal organs and six bowel-like organs, acting as the main channel through which the body’s primordial energy flows. As the saying goes, “At the Hour of Hai, the Triple Energizer opens the hundred vessels.” At this time, it is best to calm your mind, soak your feet, and allow your body to gradually cool down in preparation for sleep. Under no circumstances should you scroll through short videos or binge-watch intense dramas during this hour. Once the brain becomes stimulated, the flow of energy in the Triple Energizer becomes disrupted, leading precisely to difficulty falling asleep.
Data from the *2024 White Paper on Sleep Health Among Chinese Residents*, published by the China Sleep Research Society, shows that the average time Chinese residents fall asleep is 00:18, with over 300 million people suffering from sleep disorders. If people could slow down their pace during the Hour of Hai (after 21:00), the vast majority would see a marked improvement in their sleep quality.
How you feel after 9 pm largely determines the quality of your sleep tonight and how alert you’ll be tomorrow.
Compare your lifestyle habits against this 12-hour health guide to see how many apply to you:
☐ You often go to bed after 11 pm
☐ You’re still scrolling on your mobile or binge-watching TV between 1 am and 3 am
☐ You rarely drink warm water upon waking and don’t have a regular morning bowel movement
☐ You often skip breakfast or just eat something quick and easy
☐ You sit still for long periods in the morning, often for two or three hours at a time
☐ You lie down immediately after lunch or get straight back to work, never taking a lunch break
☐ You drink very little water in the afternoon and sometimes hold in your urine
☐ You engage in high-intensity exercise in the evening (such as sprinting or heavy weight training)
☐ You’re still scrolling through short videos, binge-watching TV series or dealing with work after 9 pm
☐ Your mind is racing before bed, and you toss and turn, finding it hard to fall asleep
👉 If you ticked 1–3 items: Your routine is generally good; just tweak a few minor details.
👉 If you ticked 4–6 items: Your body is already sending you signals; start with the easiest one to change.
👉 If you ticked 7 or more items: Don’t panic – it’s not too late to make adjustments starting today; your body will thank you for it.
V. Nurturing oneself in harmony with the seasons is the highest form of health preservation
The ‘Chinese body clock’ may sound rather complicated, but when broken down, it boils down to just four characters: ‘nourishing in harmony with the times’.
The Huangdi Neijing from two thousand years ago and the 2017 Nobel Prize—one speaks of ‘the harmony between heaven and man’, the other of ‘circadian rhythms’—have discovered the same truth using different languages: the human body is not an island; it remains in precise synchronisation with the sun, the moon, the four seasons, and the cycle of day and night.
You don’t need to adjust your schedule to match all the hours at once. Start with one or two that are easiest for you: for example, put your mobile down before 11 pm tonight; drink a glass of warm water first thing tomorrow morning; or try taking a 15-minute nap at lunchtime. For every tiny change, your body will reward you at some unexpected moment.
After all, health preservation isn’t about simply enduring the days, but about going with the flow of the day’s rhythm, treating each day as a way to look after your body.
💡 The best way to look after your health isn’t by taking expensive supplements, but by aligning your daily routine with the natural rhythms of the day—it’s free, costs nothing and has zero side effects.
References:
[1] The Yellow Emperor’s Inner Canon: Suwen and The Yellow Emperor’s Inner Canon: Lingshu, classic works of Traditional Chinese Medicine
[2] Ding Xiaoying, Department of Musculoskeletal Injuries, Shenzhen Hospital of Traditional Chinese Medicine, Ziwu Liuzhu: A Health Preservation Method Based on the Twelve Earthly Branches, October 2024
[3] 2017 Nobel Prize in Physiology or Medicine – Jeffrey C. Hall, Michael Rosbash and Michael W. Young, for research into the molecular mechanisms of circadian rhythms, Nobel Committee
[4] Chinese Nutrition Society, Dietary Guidelines for the Chinese Population (2022)
[5] European Society of Cardiology (ESC), “Association of napping with incident cardiovascular events in a prospective cohort study”, 2020
[6] China Sleep Research Society, 2024 White Paper on Sleep Health among the Chinese Population
[7] JAMA (Journal of the American Medical Association), Sleep Timing and Cardiovascular Disease Risk Study
[8] National Institute of Health and Nutrition, Japan, Cohort Study on Breakfast Habits and Metabolic Syndrome
[9] Li Dongyuan, Treatise on the Spleen and Stomach, Jin-Yuan period
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