The five factors of Sanchin development are concepts Shohei-Ryu students are exposed to in the early stages of their training (even if only to be able to recite them for promotions.) "To master the proper breathing technique" sits in the very center of the five (listed as the third) creating a perfect balance between the other factors before and after it. It is very important to know how to breathe. Not just the every day, involuntary breathing we do to maintain our life, but as an essential and fundamental factor in the development of concentration, spirit and power!
In Sanchin kata, a prescribed pattern of breathing is employed by the student as a means to train the body to coordinate their breathing with their movement. The correct technique is to drop the breath into the lower abdomen or hara and use the diaphragm to drive a circular pattern between one-third and two-thirds of the lung capacity. Inhalations are drawn silently through the nose with any pulling or drawing motion (moves into the body.) When applying strength (usually during an extending movement) additional tension is used to bear down on the hara for an explosive focus of power known as Kime, While recovering to the guard or ready position a short burst of air is exhaled through the mouth. During the exhalation, the student should place the tongue against the roof of their mouth and make a short and forceful "hissing" sound.
Sanchin exhalations are "noisy" not JUST for the sake of noise, but for several training purposes. The "noise" should be an audible representation of air being released deep from within our hara, passing through our tongue and the roof of our mouth, out of the mouth. If done properly, pushing your tongue against the roof of your mouth can help to engage the diaphragm and abdominal muscles (all part of the physical region which represents the hara) in the act of breathing. Making this audible is important because it allows you and your instructor to provide feedback on ways to improve the breathing process.
This breathing technique has multiple purposes that should develop over time:
Some experts believe that by performing regular breathing exercises similar to Sanchin breathing over long periods of time, the student is able to achieve deeper and greater concentration and control of their bodies. This is due to the fact that breathing can be controlled by both the involuntary and voluntary or conscious part of the mind. By increasing the ability to control the breath, the student can tap into the "involuntary" mind, and learn to control other aspects of the body. This is how students of certain schools of meditation are able to voluntarily lower their heart rate, or body temperature!
The average student may never achieve THAT level of consciousness, but Sanchin breathing will, at least, provide them with the ability to concentrate better, have more intense spirit, and be stronger.
It is not uncommon for students to resist performing the Sanchin breathing initially . . particularly the audible part. They may feel embarrassed or foolish about making a noise that the average person does not understand, but this concern of being judged by others has no place in the dojo. It is driven by the ego, which must be minimized along the long road to true development of the mind. The student must let go of these uncomfortable feelings and connect their breathing to their concentration and spirit. Sanchin breathing should ultimately become similar to the Kiai, as an EXPRESSION of the student's intensity, determination and awareness.