Medical research (over 20 studies) also testifies about horrible effects of supine sleeping on different groups of adults. Scientific articles found that sleeping on the back leads to higher incidence of sleep paralysis (with terrifying hallucinations), stroke, asthma, increased airway resistance (since CO2 is a natural bronchodilator), and sleep apnea episodes. Several studies found lowered blood oxygenation for sleeping on the back. These abstracts are quoted in Module 6-B: Best Sleep Positions.
If you are still uncertain, do your personal testing
Measure your body oxygen level (the CP test) after sleeping in different sleeping positions since body oxygen level, according to all available medical evidence is the best and simplest known DIY test for personal health. The CP reflects your stress-free breath-holding time after your usual exhalation. You can use an electrical clock with elimination showing seconds or a ticking mechanical clock so that there is no need to turn the light on during night. Note that you should spend about 10-15 minutes in a certain position in order to achieve a stable metabolism correspondent to this sleeping position before you can measure the effect of any sleeping position on your health. Sleeping on the back is worst and causes lowest body oxygenation since our breathing is unrestricted: our belly and chest muscles can move without any restrictions. As a result, sleeping on one's back intensifies breathing and leads to appearance of the ineffective, heavy, and/or irregular breathing pattern. See respiratory patterns types for details.
If you find that your CP does not decrease (or maybe even improve) after sleeping on your back, you must sleep on the back all the time. However, thousands of people tried sleeping on one's back and all found that it causes reduced body oxygenation and worst health. [The only exception I have heard about relates to American Indians who probably slept on their backs some 2-3 centuries ago, while propping their heads against a stone so that their chins were pressing against their chests. If you try it, you can find that it is hard to breathe in this position. Furthermore, their sleep was probably about 2 hours due to around 3 min CP - see the Buteyko Table of Health Zones. When you get over 60 s CP, you can sleep in any posture you like and you will have more flexibility and freedom what to do.]
Dr. Buteyko and his colleagues about sleeping on back
None of Russian Buteyko doctors ever met or heard about such people. Why? According to Dr. Buteyko (Dr. Buteyko's Lecture in the Moscow State University, 1972),
Many severely sick patients remain sitting up, afraid to lie down. This is sensible. We should lie down only for a minimum amount of time, and only when sleeping. Our patients with deep breathing practice [breathing exercises], but cannot control their breathing at night, and hence, sleep is actually a poison for them. The longer he sleeps, the more chances that his breathing will be increased causing attacks. Therefore, we wake him up after 1-2 hours, he practices decreasing respiration...
Children, especially asthmatics, or the deep-breathing children turn themselves over on the tummy during sleep. And here it begins: the parents are on guard, the fight goes on, sometimes for years. The child turns on the tummy hiding its head under the pillow, but no, they turn him over to face up. Again and again he tries to rescue [himself], but they will not give in. There is no rest for him, nor for the others. And if we take a child sick with asthma, he sleeps on his back and wheezes. He turned on his tummy, the wheezing disappears in a minute. [He is] again on his back: in a minute the wheezing starts again.
Sleeping on the back for many sick people means about twice as much breathing and corresponding CP drop. This often causes acute symptoms due to early morning hours and death in severely sick people. Hence, Dr. Buteyko, his medical colleagues who practiced the Buteyko breathing method, and their numerous patients used variety of tools, methods and techniques how to prevent sleeping on the back.
Methods to prevent back sleeping
1. Some people were sleeping with a backpack to prevent turning on the back. This is one (“awkward”) option.
2. It is possible to prop oneself from the sides with pillows.
3. Another option is to sew a pocket on the back of your night shirt and put a tennis ball there.
4. Or one can take a sock and wrap it around the middle of a belt making a knot. The belt can be positioned around the middle of the chest with the knot on the back of the person. The knot should be big enough to prevent the person from sleeping on the back and it would not wake the person up since it is soft.
5. Currently, the most popular solution is to take a double cotton layer (strip) of bed linen about 2 m long and 20-30 cm wide. Wrap it around self, make two knots on your chest and move them on your back. A simple scarf can be also used.
Practice of Buteyko breathing teachers shows, that sleeping on the back is the sign of low CP. This problem is present when the CP is about 20 s or less. Once, your morning CP is over 25 s, you are very unlikely to sleep on your back at all and there is no need to use any of these techniques.