For us to be healthy, we need to use our body in the correct way. This is something everyone knows. It is our mind which uses this healthy body. When we feel unsettled, we get red in our face. When we feel scared, our face becomes white. The condition of our mind has a huge influence on our body. We use our awareness a lot for the outside, but what is important for us is this condition of our mind. Yet this mind has no form and receives much influence from the outside. Any change in the outside and our mind will react. According to the reaction we can become quiet or upset.
Trying to align this mind of no form is not easy. When our heart is beating fast, then we cannot calm it down by will. There is an easy way of going about it by calming our breathing. Yet it needs to be the correct breathing which can bring enough oxygen to all the 6 trillion cells we have in our body. Exhaling long and inhaling naturally. For this we need to use our skeletal muscle which are moving according to the command of the brain. The heart pumping the blood through our body which is enriched with oxygen in the lungs. When we are bed ridden, skeletal muscles are used a lot less, that is where we are not using the breathing in the best way. Thus it is good to move the body so that a strong blood flow can come about. A long exhalation will also invigorate the skeletal muscles and thus the capillaries are stimulated.
Different emotions and uncertainty as well as little physical motion weaken the blood flow. When we exhale long, we again invigorate the blood flow. The lungs do not move by themselves, but by the motion of the diaphragm. Our inhalation and exhalation move through the same one breathing pipe. If our exhalation is not deep enough, then the inner pressure of the lungs does not become less. Thus we cannot take in enough oxygen while being surrounded by it. That is our problem.
If we can exhale long, then we lower the pressure in our lungs and naturally the lungs when expanding will want to take oxygen in. Thus we do need to use our awareness to again lengthen our breathing which has become shallow and short because of the outer tensions which we absorb. This is the important breathing of zazen. If we do not take this as important, while we do have the ability, we cannot contain our emotional and psychological reactions. This is the place where we have to use our awareness well. Too much noise and weak concentration is why we need to make efforts.
Please do not stop at reading this only, but actually bring this breathing practice into your daily life. Please continue and become a master of your breathing
-Shodo Harada Roshi