To different types of our activity there correspond different types of breath. It is not obligatory to be yoginy to notice that during run we breathe not as sitting in chair and that our respiratory rhythm during wakefulness is other than that which is established during dream.
However yogina have studied this phenomenon more carefully and have revealed thinner ratios between different types of breath and human activity, - not only physical, but also emotional and intellectual. The person captured by anger breathes not as frightened, breath of the person happy differs from breath of the neurotic. To define physical and mental condition of the person, the yogina is enough to be tracked how he breathes.
Old Indian Risha have studied all parameters of breath: length, rhythm, duration, amplitude, center of gravity. We now will also be engaged in breath length. How it is measured? The way is very simple and consists in that, having moistened palm to place it under nostrils. You will notice that during exhalation the palm feels flow of the coming-out air. Slowly you take away palm down to that time until you cease to feel this flow. Having measured distance from palm to nostrils, you receive the approximate length of your breath.
Yogina have measured the average length of breath in "fingers" for different types of human activity - from run and to condition of Samadkhi ("finger" is equal to about two centimeters).
In Gkherand Samkhite, one of classical treatises on Yoga, the following is said (verses 84-86):
"The body contains 96 fingers (about 180 cm). The flow of the air which is let out at normal exhalation has length 12 fingers (that corresponds to about twenty centimeters). When singing this length reaches 16 fingers; at hotba 24 fingers; during dream of 30 fingers; during sexual intercourse of 36 fingers; and during performance of hard physical activity and that it is more. Gradually reducing the natural length of flow of the exhaled air, we reach increase in life expectancy while extending breath we shorten it."
Besides, Risha have noticed that what has more concentrated mind, that breath is shorter; Samadkhi it in general imperceptibly is able.
To reach the maximum concentration of mind, yogina recommend, having realized breath process, to gradually reduce its length.
Sit down in your favourite pose: the backbone has to be straightened and vertical, and the head is counterbalanced. Relax and sit not movably as if statue. Consciously, second after second, you monitor breath, the movement of breath and exhalation. During breath which has to be full and deep feel how air gets into nostrils, nasopharynx, throat, bronchial tubes further. At exhalation you brake the air flow leaving nostrils, shortening thereby breath length. The exhalation has to become more and more silent, quiet, silent and slow, remaining at the same time deep. No delays or irregularities should break either breath or exhalation. Such conditions are optimum for gas and pranichesky exchange.
The basic elemnty this exercise (as, however, and all others) is concentration: do not dare to distract. You will tell that it is very difficult. Then resort to the help of some Mantra. I recommend to Europeans Pranava, that is mental silent repetition of syllable of OHMS. At first you can pronounce five times this word aloud, forcing to vibrate "About …" in thorax and throat (half of time of exhalation) and "M …" in skull, and do all this more silent until the sound stands and repeats only in mind. The "OHM" said about itself makes more intensive mental and pranichesky operation, than the "OHM" said aloud.
Thus, for some time breath shortening has to become your purpose. Having concentrated sufficiently, direct mind to that it was more and more absorbed in mental pronouncing "OHMS"; give the chance to breath, "OHM" - at and to mind to be confused, integrate to such an extent that they could be dismembered difficult. Between breath and exhalation there should be no pause unless in fraction of a second. If you too tighten your exercises, then you can fall asleep. It should be avoided though the dream, of course, will not do to you any harm. One of the purposes of exercise is the managed conclusion to surface ("exposure") unconscious. Really, thanks to practice such it is possible to enter condition of the peculiar pseudo-dream which is not covering completely all consciousness imperceptibly.
In this case there can be light whirlwinds of different color. They should not disturb you: it is phosphene which is result of activity of unconscious. It is not necessary to look for them or to aim at them, but they do not follow as well to discard. Remain in relation to them simply neutral. These manifestations are rather rare, and we speak about them only in advance to calm people who have them perhaps will appear. ("phosphene" also light circles arising before eyes at the time of pressing on eyeball are called)
After exhalation slowly stop breath and concentrate your attention at the backbone basis - on sacrum. In delay time it will be rather easy for you to focus consciousness on this area. You can notice vibrations there.
Anyway, provide that you send flow of prana which can be concretized to this place, presenting in the form of light or heat. Having practiced some time in such representation, you will clearly feel feeling of heat and even some pricking in the place of concentration. Perhaps, of course, that no feelings will also appear; but it does not mean at all as if exercise has not given the expected effect. Any persistent and long occupations with need bear fruits even if engaged about it does not suspect.
During breath lift your consciousness along backbone, representing that this heat moves from below up. Thereby you will carry out prana (which as we saw from the previous example, will obey mind) along spine.
Never, except emergencies, interrupt this exercise suddenly. Practice it, whenever possible, in the place where you will not be prevented.
Return to conscious condition of wakefulness is made upside-down, that is at first the sound "About … …" is said by m internally with gradual transition to pronouncing it aloud and breath lengthening.
This exercise is absolutely safe as the breath delay at empty lungs cannot do any harm. At the same time it makes very deep influence on mentality: "dissolution" of conscious mind leaves intelligence in condition of wakefulness and at the same time develops intuition.
Regular daily five-minute practice of this exercise, it is desirable on rising and on sunset, mind will calm, and certain unusual serenity will light up your day. You feel as well considerable pranichesky influence: the prana released at the basis of pozvonochinik and directed along it will continuously dynamicize and vitalizirovat all vital centers.