Biorhythm – the internal clock

Like almost all living beings, human beings follow biological rhythms and cycles, which have turned out to be vital in the course of development. The connections are being researched by a fairly young scientific discipline, chronobiology. The day-night rhythm, which regulates work and rest phases and is prehistorically closely related to the distribution of light during the day, is particularly well known. What is biorhythm, how does the internal clock work and what is the Chinese clock?

Biorhythm: The internal clock as a pacemaker

The same applies to the day-night rhythm for summer and winter time, which affect the human body through the different lengths of exposure to the sun – long periods of rest in winter minimize energy requirements and ensured survival even in primeval times. This is why it used to be thought that the organism reacted to a rhythm given from outside.

In the meantime, however, we know that we have our own clock, the  internal clock. Although it reacts to external influences, it continues to tick even when environmental factors such as the light are switched off. It is controlled by processes such as the release of the hormone  melatonin .

Biorhythms: cycle of the body

The natural fluctuations in bodily functions as continuous changes in the organism that occur in recurring cycles are called biorhythms. Important biorhythms in humans are: 

• the sleep-wake cycle
• the activity cycle
• the rhythm of eating and drinking
• the body temperature rhythm
• endocrine rhythms

Other forms of biological periodicity are the female menstrual cycle, the heartbeat and the renewal of the blood cells.

These examples make it clear that humans are not only subject to a 24 to 25-hour daily rhythm that is controlled by their internal clock ( circadian rhythm ), but that other shorter ( ultraradian rhythm ) or longer ( infraradian rhythm ) cycles also play a role to play.

What we need our inner clock for

The biological clock plays an important role: it tells our body when it can be active and when it’s time to slow down. It influences our bodily functions – blood pressure, body temperature, hormone balance.

Control center is a nerve core (nucleus) in our brain – no bigger than a grain of rice. It lies at the level of the bridge of the nose above the junction (chiasma) of the visual pathways, which is also where its name comes from: suprachiasmatic nucleus, more simply: SCN. It is controlled by brain function and hormones and reacts primarily to differences in light that are transmitted to it by special cells in the retina.

Life circumstances bring biorhythms out of sync

What used to be quite easy to do is now a constant challenge for our inner clock: whether night work or shift work, disco evenings, long-haul flights or time changes in spring and autumn – the days are getting longer due to artificial light, the rhythms of life no longer correspond the light and dark times or change again and again at short notice.

Our organism can temporarily compensate for this, but in the long run this hard work leads to physical and mental disorders. If the individual daily rhythm is constantly ignored, this can lead to  sleep disorders , a drop in performance and moods, and even  depression  , and the risk of physical illnesses also increases.

Chronotypes: Of larks and owls

Another aspect is that there are different time types (chronotypes): The “larks” (early risers) and the “owls” (morning grumps). They have different sleeping and waking times and differ in how long they sleep. If they live constantly contrary to their individual rhythm – for example due to rigid working hours in school and professional life – the risk of problems also increases.

Die Chronobiologie

Sleep researchers and time biologists have been increasingly on the trail of these connections in recent years. As an interdisciplinary science, chronobiology investigates how biorhythms and internal and external (environmental) factors are related and what effects our lifestyle has on health. The more insights chronobiology gains, the louder the voices grow to design our everyday rhythms in schools, business, employment and leisure time so flexibly that we don’t have to disregard our inner clock.

The Chinese organ clock

In traditional Chinese medicine (TCM), temporal processes such as the seasons, phases of the moon or daily rhythms have always played an important role. They are traditionally attributed an important influence on well-being, so that they are taken into account in both diagnostics and therapy. There is a special connection between the time of day and organ function.

A model based on a clock is used to illustrate this, in which each 2-hour segment is assigned to an organ (or a so-called meridian) where this has its highest energy flow, i.e. it is particularly active but also susceptible to disturbances. If symptoms occur again and again at certain times of the day, this may indicate a disorder in the associated organ:

3.00-5.00 a.m.
The lungs take off: people with  heart failure  often wake up between 3.00 a.m. and 5.00 a.m. because they are unable to breathe. The water in the body has then reached the lungs and the lungs are working at full speed. The body reacts to this high performance.
As a subsystem of the lungs, the skin plays a special role in temperature sensing: many affected people get cold and the cold wakes them up.

5.00-7.00 a.m.
The colon gets going: Many healthy people have a bowel movement between 6.00 and 7.00 a.m. in the morning. This regularity also allows conclusions to be drawn about the time and type of the last meal the day before.

7.00-9.00 a.m.
Stomach time: This is the time when digestion is smoothest and hence the popular recommendation to eat like a king in the morning. People with  low blood pressure  experience a drop in blood pressure around 11:00 am and can counter this with a cup of broth or other light, salty food.

12 hours later (7:00-9:00 p.m.) the stomach hardly works at all. The food stays in your stomach until the next morning and you get up in the morning feeling full. Therefore, you shouldn’t actually eat any food after 7:00 p.m., because the  food  has 12 hours to ferment and rot at 37 degrees Celsius.

9.00-11.00 am The
spleen and  pancreas  are stimulated: During this time, the pancreas works at full speed and releases most of the  enzymes  and ferments. Therefore, the spiritual learning ability of the individual is at its best during this time. Tests during this period take place under optimal conditions. Surgical interventions can also be carried out best during this time, since enzymes  prevent inflammation  and accelerate wound healing.

11.00-13.00 Maximum time
of the heart: Since the heart works continuously for 24 hours, these 2 hours are mainly used for the heart to regenerate and it must be rested for this period. For many advocates of the biorhythm, physical exertion,  stress  or  operations  are not justifiable during this time.

1:00-3:00 p.m.
A full stomach… In this phase, the small intestine needs an optimal blood supply. Additional muscle work is not the order of the day, since the resulting blood shift to the periphery leads to digestive disorders. The afternoon nap after eating or the ban on swimming with a full stomach are based on this fact.

3:00-5:00 p.m.
The bladder works at full speed: Most of the urine is usually excreted during this period.

5.00-7.00 p.m.
The kidneys are particularly active

19.00-21.00
The circulation has warmed up: it is the time for rest and relaxation of the main organs.

21.00-23.00
Regeneration of the endocrine glands

23.00-1.00 Maximum time
of the gallbladder

1.00-3.00 a.m. Maximum time
of the liver: Alcohol is broken down well during this time. When the breakdown is complete, many people wake up because the level of sugar in the blood has fallen sharply as a result of the metabolic process. By the way: Western medicine is also familiar with such a phenomenon: Emergency doctors see biliary colic particularly frequently around midnight, asthma attacks in the early hours of the morning and  heart attacks in  the morning.

Biorhythmics as pseudoscience

The term biorhythm is also used in the context of biorhythmics, a pseudoscience that assumes that life is subject to three rhythms of varying duration (between 23 and 33 days) – physical, emotional and intellectual. Models are used to calculate good and bad days based on date of birth and gender.

This speculative form of regularity was propagated by the doctor Wilhelm Fleiss at the beginning of the 20th century and lacks any scientific basis.