So, if I can summarize my understanding now, it is blood CO2, influencing blood pH (as influenced primarily by CO2 in the blood), that provides the basis for our breathing rate, and not O2 (as it has less of an effect on blood pH), under normal circumstances, which can be defined as when intake from the lungs to the blood vessels is adequate, and when tissue oxygenation is adequate as well. So under such circumstances, if serum CO2 is too high, respiratory compensation kicks in, and breathing rate is increased in order to expel CO2 from the lungs.
If serum CO2 is too low, there is no respiratory compensation for that. In this case, there would be lower tissue oxygenation (Haldane effect), and the body would simply make do with the lower tissue oxygenation, by conserving the use of oxygen by resorting to other metabolic pathways that require less oxygen. In other words, if serums CO2 is too low, there is no "reverse respiratory compensation" that would automatically lower breathing rate to retain more CO2 in the blood. This is where the person has to train himself to breath less. The Buteyko method is one way to do so.
So, there is an active system of respiratory compensation ongoing that would keep our body from excess blood acidity from excess CO2, but no active system of "reverse respiratory compensation" to keep the body form excess blood alkalinity from a lack of CO2.
So the body is active in correcting for an excess CO2 situation, which I believe is mostly externally induced, but isn't active in correcting for a CO2 deficiency situation, which happens often.
Under normal circumstances, it is CO2 which determines breathing rate. In an oxygen deficient situation (arising from either poor lung intake of oxygen or poor tissue intake of oxygen), oxygen becomes the determinant of breathing rate.
The Buteyko method is a method of increasing serum CO2 levels, by making possible a higher retention of carbon dioxide in the blood, increasing levels of tissue oxygenation. Other way to address low serum CO2 levels is thru better nutrition- more sugar - to complement increased tissue oxygenation - in providing the necessary input for respiratory oxidation, in which carbon dioxide is produced. Ensuring the availability of enzymes that effect respiratory oxidation, with vitamins and minerals, and adequate protein intake - will help further effect respiratory oxidation. The more the body relies on respiratory oxidation for energy, the more carbon dioxide is produced and used to maintain proper support for tissue oxygenation.
Most of the time, under normal circumstances, the problem of CO2 excess in the blood doesn't arise. It is the problem of CO2 deficiency which creates conditions that need to be addressed actively and consciously by a person. The sad part is that the medical profession is focused on the CO2 excess side, and does little or nothing to address the CO2 deficiency side of the equation.
The medical norm of carbon dioxide concentration in the human body is around 5% (35-37mmHg). Dr. Buteyko found that people who had optimal levels of carbon dioxide never suffered from any chronic diseases and the greater the deficiency of carbon dioxide a person had, the worse their overall level of health. (p. 218 Cancer Cured...)
Where do you stand in terms of carbon dioxide concentration? I am at 30.
I think other factors can affect blood pH too, but CO2 is an important one.
Right, if the CO2 set point is in line with optimal CO2 level, and one is not at extremes of oxygen and CO2 levels.
If the set point is in line with optimal CO2 range, there is respiratory compensation. Breathing rate slows. You might notice the occasional spontaneous holding of breath. Even if the set point is lowered, there can be respiratory compensation if the CO2 level dips below that set point.
AIUI, the chronic problem arises when lowered CO2 conditions have persisted long enough to reset the CO2 set point to a lower than optimal level. Chronic stress or other causes of chronic hyperventilation can reset it. Then you don't get the automatic slowed breathing to compensate and bring the CO2 level up to a high enough level to provide optimal O2 supply to tissues, and you can leave some tissues and organs struggling with reduced circulation, and chronic mild (or sometimes more severe) hypoxic conditions.
It's when the set point has been lowered that retraining to raise the set point can be helpful, by Buteyo or other methods.
We are evolved with mechanisms for both, but most of us are living in conditions for which this system is not optimally evolved. Our systems are well designed to handle occasional short intermittent stresses that require a burst of skeletal muscle power (supplied by increased breathing). We are not evolved to handle the continuous unrelenting chronic stresses common in today's civilisation. Adrenaline tends to promote hyperventilation.
I think this is only in extreme situations.
Buteyko method is primarily about learning and practicing reduced breathing, but he also had lifestyle guidelines to support this, including some about diet.
I think so.
As far as I'm aware the medical profession spends much time focussed on CO2 excess either, except in particular cases where it really is an issue, though they do often deliver oxygen that would probably work better if it came with a suitable proportion of CO2 mixed into it.
I do think many of them are probably unaware of the significance of hyperventilation and lowered CO2 levels.
I don't know if I've ever had mine measured. But my CP is terrible, consistent with chronic ill health. Better than it used to be, except that I had a recent set back from an acute illness.