The purpose of breathing, as everyone knows, is to supply the body with oxygen and cleanse it of carbon dioxide. Cut off the oxygen, retain the poisonous waste gas, and death will follow in a matter of minutes. This is elementary. What is not so clear is that an _inadequate _supply of oxygen--that is, improper waste disposal--results in half living. The body functions are slowed, the tissues fail to renew themselves. Yet this unsatisfactory state of affairs is so common that we actually take it for granted. In fact, leading chest specialists say that the average person today utilizes only about one-eighth of his lung capacity, a capacity which was right for him back in the days when he lived in caves and spent all his waking hours actively engaged in the business of surviving.
Even when we are not living at par, the heart does a prodigious job. Every hour it pumps some 800 quarts of blood through the lungs which, in turn, eliminate some 30 quarts of carbon acid during that time. The heart beats 100,000 times a day, which means it generates enough energy to lift a weight of 130 tons a foot high. It pumps enough blood in a lifetime to float the largest ocean liner. Imagine what power our heart might have, what energy it could generate, if only its supply of oxygen were increased eight times!
As the freshly-oxygenated blood travels from the lungs to the heart and is pumped on, via arteries and blood vessels, via tiny capillaries, it reaches every cell in our organism. It makes possible the utilization of our food intake for the body's various needs, rebuilding tissues, supplying energy. It stimulates the functioning of the endocrine glands so that their secretions may be better absorbed. It feeds the nerves. It feeds the brain. Then, through a second set of capillaries, dark red now instead of bright, for it is loaded with waste, it travels back through the veins to be cleansed once more. All of the blood in the body makes this trip to the heart every three minutes.
Now what of the lungs? Why is it that most of us do not use our respiratory system properly? Partly the answer is, again, that we have grown effete with civilization. The physiology of the human body remains geared to that primitive state when man hunted, climbed trees, split rocks, and there is little we can do to change this. In a sense we now have too much equipment for our needs, and we are letting it grow weak and flabby with disuse. This imbalance, by the way, has been largely responsible for the prevalence of tuberculosis and our susceptibility to it until the development of wonder drugs changed the picture.
But the anachronistic way we are built is not the only reason for our being oxygen-starved, nor for the various respiratory ailments and infection from which so many of us surfer. The fact is, few of us breathe properly.
Look around you. You will be astonished to notice how many people breathe through the mouth instead of through the nose. This means they inhale directly through the pharynx and the larynx (roughly, together, the throat) allowing air to reach the bronchial tubes without being properly filtered and warmed. In order to be cleansed of dust and bacteria air should be drawn in through the nasal passages where the mucus membranes with their secretions filter it. Moreover, as that air then travels a considerably longer road it is warmed to body temperature instead of being allowed to hit vital organs with chilly shock. Breathing through the mouth, then, is an invitation to colds and infections of all sorts.
One final aspect, too often disregarded, of proper breathing is that it must be done from the diaphragm. Women especially, because of tight clothing and girdles, tend to breathe by lifting the chest, consciously drawing the air in. This is less than half-effective, both because the upper lobes of the lungs are the smallest and because the upper part of the rib cage is relatively rigid. The correct way to breathe is to expand the muscles of the diaphragm down and out, then push in and up. In this way the lungs expand to full capacity, air rushes into them, then is vigorously expelled. If you try it, you will quickly see how even a minute or two of such breathing can be enormously exhilarating. But very few of us breathe this way naturally. It is something which must be learned by practice.
Yoga deep-breathing exercises, as you will see shortly, give the body this exhilaration. Some you will find extremely simple--so simple you will wonder why they should be dignified by such formal attention. The answer is that because of this very simplicity they can, if done regularly, soon become automatic, a fine new habit. Moreover, like the more complicated ones, they are a most important adjunct of the practice of relaxation and concentration. Bear in mind always that one cannot be achieved without the other, and neither can be reached without an understanding of the purpose of both.
Try this first experiment in Dynamic Breathing: Stand straight but relaxed. Breathing as smoothly and rhythmically as possible, with the mouth closed, inhale slowly and deeply while expanding the diaphragm, then exhale by pushing the diaphragm in and up. Take as long to inhale as to exhale, although normally inhalation involves a shorter movement than exhalation. While striving to equalize and slow down your normal tempo, visualize your limbs as hollow tubes through which the life-giving prana is being drawn into your body. Picture this energy flowing into your organs, bathing your entire body and cleansing it. As you exhale, visualize fatigue and exhaustion passing out of your system along with the poisonous wastes you breathe out. Finish with what we call the "Cleansing Breath:" Inhale deeply, then, when your lungs are fully extended, expel the breath suddenly and energetically, using a quick inward jerk of the abdomen to drain the lungs of all air. Repeat the cleansing breath two or three times, and you will be amazed at its bracing effect. After you have become expert at Dynamic Breathing, you can practice it at odd times during the day.