I found an ebook by Max Sick and Monte Saldo who came up with the Maxick system of exercise. They were both body builders and athletes.


Page 130-131 states:

versal of the process establishes maximum expiration.
The raising of the chest by the elevation of the ribs is a more complex matter than the descent of the diaphragm, and is achieved principally through the medium of the external intercostal (between rib) muscles and the serratus magnus muscle. The former enlarge the the spaces between the ribs, and the latter ­as it passes from the shoulder blade to the middle of the first eight or nine ribs, raises the ribs when the shoulders are fixed, and is therefore the most important muscle of inspiration. Here I must digress for a moment to point out that the usual belief that very supple and slim persons have the best breathing capacity is fallacious. It is such people that are usu­ ally physically weak and victims of pulmonary troubles. The better the bulk and the de­ velopment of the respiratory muscles, the greater will be the rib separation be when the impulse of the inspiration is active. So, while suppleness is an essential to full tidal breathing, it is not the only essential, and those desirous of gaining superlative endur­ ance should master the control exercises of full shoulder blade expansion, and those exercises that isolate and develop the serratus magnus muscle, as an indispensable foundation.
We are told that when the new­born infant takes its first breath it inspires an approx­ imation of one hundred cubic inches of air. This is known as the residual capacity, and although constantly changed during respiration, the lungs can never be emptied of air during life.
Breathing is an involuntary function, continuing as it does throughout sleep and coma, but voluntary acceleration and increased capacity can be made with benefit to the health and a great saving of work to the heart under strenuous activity, as you will be able to prove to your own satisfaction if not already convinced of the fact.
Before dealing with breath control it may be necessary once more the two main fal­ lacies that seem to be trotted out on every possible occasion by self­styled physical training experts, who always seem to be able to get limitless space in the Press4. The first is the ridiculous advice to inhale through the nose and exhale through the mouth. The so­called experts want us to go about looking like fish. If this were the natural method of breathing we would see babies opening and closing their mouths every few seconds. Except under stress, respiration should be absolutely nasal. Under the stress of great physical exertion some persons find themselves unable to inspire sufficient air

You will find that two things have defeated the argument of the abdominal breathers. The first is that you can take in a greater volume of air, and the second is that the ab­ dominal distension has practically disappeared. You will further find that if the thorax is fully expanded, and you have taken in your limit of air, the abdomen will not distend appreciably. This proves definitely that the so­called abdominal breathing is completely useless, and any person capable of understanding the effect of downward pressure on the abdominal organs will understand also that Nature would hardly enforce a dis­ placement of the internal organs under the natural exertion of running, with the neces­ sity of an increased supply of air. Did you ever see a racehorse or greyhound bulging like a balloon when racing? The “abdominal” breathing and other age­old fallacies have to be contradicted and fought all the time, because for some unfathomable reas­ on, the more obviously foolish such fallacies are, the more honour they seem to bring to their supporters. You can now prove otherwise and so help in the fight against a dangerous and out­of­date superstition7. It is best not to waste time arguing about it, but to prove by practical demonstration that you are right. If the danger were only con­



http://maxalding.co.uk/Philosophy/E-books/psp-max-ebook.pdf

I think it's sound advice. In a nutshell he says that people who advocate belly diaphr breathing tend to be out of shape and have a gut. When you are doing real exercise you will naturally breathe through your mouth and be chest breathing.


Any attempt to breath from nose to mouth with diaphragmatic breathing might cause injury and will result in a lack of oxygen.

Timber...lol