It is known that modern people sleep, on average, about 7.5 hours per day. Studies also found that length of sleep varies from person to person and generally gets shorter with aging: infants can sleep up to 12-18 hours per day, young children for 9-12 hours, teenagers about 8-10 hours, and adults from about 6 to 9 hours. It is also known that with progression of many chronic diseases (heart disease, cancer, diabetes, COPD, etc.), people generally require more time for sleep. Wilful attempts to decrease length of sleep for all these categories of people have been unsuccessful, although some individuals may have shorter sleep requirements.
However, according to clinical observations of about 200 Russian medical doctors practicing the Buteyko self-oxygenation therapy, when former patients achieve superior body oxygenation, they naturally need only 2 hours of sleep and have no desire to sleep more. How does it work and why?
Virtually all chronic conditions have tissue hypoxia (low body oxygenation) as a normal feature. In cases of cancer, heart disease, and COPD poor cellular oxygenation is the central factor that defines progression of the disease and the treatment methods used. At the same time, the breathing pattern of people relates or even defines body oxygenation. Let us consider these links between oxygenation, sleep, and breathing.
For severely sick and critically ill people, less than 10 s of oxygen in the body is typical. (To measure oxygenation, exhale normally, and count your breath holding time in seconds, but only until the first signs of stress or first desire to breathe.) Most of these patients have very poor quality of sleep, while duration of sleep can be up to 10-12 or more hours. The breathing pattern of these people, as we can easily see it, is deep and heavy.
When these sick people achieve about 35-40 s of oxygen in the body, they naturally spend only about 6 hours for refreshing and quiet sleep. Most people practicing the Buteyko oxygenation therapy are satisfied with this level of health since they do not experience symptoms of their diseases and do not require medication at this stage.
However, hundreds of Russians continued to progress further. They increased their body oxygenation up to 2.5-3 minutes and discovered that their sleep get reduced, again without trying (!), down to 2 hours only. Doctor Buteyko and many his medical colleagues were practical examples of this effect.
Remarkably, the same observation (about 2 hours of sleep in perfect health) can be found in books about another breathing retraining technique "hatha yoga" ("hatha yoga" means "master of breath").
For both systems, hatha yoga and the Buteyko method, the goal is to reduce/restrain breathing using special breathing exercises and natural means. Physiologically, this goal makes perfect sense since thousands of medical studies proved that the more we breathe (at rest), the less oxygen our tissues get.
Both therapies (hatha yoga and the Buteyko method) use the same method to test one's current health state: stress-free breath-holding time test after usual exhalation. It is a simple DIY test: after your usual exhalation, pinch the nose and observe how many seconds you can hold your breath without any stress. (You should not have a deep breath after the test or gasp for air when you resume breathing.)
However, the Buteyko method is more specific and scientific. It was developed by Doctor Buteyko during the 1960s when he led the classified project funded by the Soviet Ministry of Aviation and Space Exploration devoted to study of optimum air composition in spaceships for maximum oxygenation of first Soviet astronauts. Dr. Buteyko studied interactions between unconscious breathing patterns, breathing exercises, body oxygenation, and various systems of the human body. He realised that deep or bog breathing reduces body oxygenation and causes dozens of other physiological abnormalities.
There are several different mechanisms how breathing and body oxygenation influence our sleep. They involve oxygenation and relaxation of our brain and muscles, stability of the central nervous system (over-breathing destabilizes the nerve cells), blood flow, work of the immune system, activity of hormones, parasympathetic-sympathetic balance, and many other processes.