Thanks for the great comment. I WANT to agree because of the positive light you framed everything in but I'm not sure I'm following it all. I read it three times but I'm not familiar with all the Yoga terms you used and I'm not sure exactly what you're getting at.
I'll try to reply to the things I did understand but first I would like to perhaps strike the word "natural" or "unnatural" from the conversation. Natural and unnatural are very wishy-washy and muddy words and they can be used to justify or condemn almost anything under the sun. So by that token you can ALWAYS say that some way of breathing is "natural" because humans do it and we can't really do "unnatural" things. I just realized I lapsed into that language in the article and it is imprecise to at best. I have corrected the article (and thanks for that) to remove such language but I want to say that when I, personally, use the words natural or naturally I mean them in a very specific way which is "without thinking" or "without affectation".
So if I were to say 'breathe naturally" I wouldn't mean "how mother nature meant you to" but "without trying or striving to breath in a certain way". In this way what is natural would depend on where each individual is at. If you "breathe naturally" in a state of chronic stress or anxiety that may well be inverted breathing. But that does not mean it is "correct".
I covered the stress triggered and also exhaustion triggered aspect of it in the earlier article, On Breathing and Strongman. I also have an article that covers the flight or fight response in some detail. Although that is a "old" concept and the basic tenants have been updated somewhat and expanded on.
I would like to start by saying that most people who are observing Paradoxical breath are only seeing it from the negative side. Many people with psychological disorders that deal with high stress usually can have paradoxical breath as a symptom. This is also a breath that can be triggered during fight or flight situations. But this is only when the breath is introduced to the person via the autonomic nervous system
It seems like you are saying it is "okay" if you do it as an exercise or on purpose. I don't know what the intention of doing so would be and I don't see what intentionally breathing in a way that limits the deepness of the breath could do. Also, you mentioned paradoxical breathing triggered by the autonomic nervous system. Well it works both ways just like you said but you many not be thinking that intentionally creating an incorrect breathing pattern could lead to a stressed or "unstill" mind just as having a stressed or unstill mind could lead to an incorrect breathing pattern.
Yes people will automatically turn to a high chest breathing pattern, one that is accessory dominated, during times of stress or exhaustion from exercise but this does not mean that such things cannot be avoided and that they are somehow "good" in the sense of being natural. I do understand that you are talking about ancient practices and I have a great deal of respect for Yoga breathing practices but that doesn't mean it all makes sense physiologically.
this leaves some debate on whether or not the push up the belly out on exhalation is necessary when discussing the action of paradoxical breath. A natural exhale drops the belly… while the natural inhale lifts the belly. Open for discussion on this thought.
I can't comment much on that because I would never recommend paradoxical (inverted) breathing to be done intentionally so I don't have any opinions how to do it better! I will say that the 'correct' inhale (i'm not going to use the word natural) only raises the belly a slight bit. A very slight bit actually and most of the action of the belly is expansion. This expansion should ideally happen around the whole "core" or torso (not to confuse the torso with the COG).
I can't comment on the other specific practices you mentioned or the claims attached to them. The articles are meant to help people who have through stress and shear habit been locked into a high chest breathing pattern. Whether there is a "use" for inverted breathing is beyond my experience but I am dubious about the claims, to be honest. It doesn't fit with my knowledge but my knowledge is limited on the subject of Yoga.
If someone were to come to this article and find that they have this problem I think they would be helped by it! So I don't think that a person who is locked into an unhealthful breathing pattern (which can cause all the many problems I discussed) will find it a gray area! In fact I think if someone did have this problem the thought that it was not a black and white issue would not do them much good. I do agree with the general notion that nothing is entirely negative though and that it depends upon perspective. In fact many of my writings are about ways to turn negatives into positives so I commend your philosophy on that. As a strength trainer, however, I can't really get with the idea that nothing is right or wrong; it just is. If I thought that I'd get trainees injured in a very bad way!
David, thanks so much for the great comment and participation.