Breathing - the first act outside the womb to prove if we are meant for this world or not. It is our first and most immediate link to our environment. It is the line where the external world blends with the internal. It is basis for activity, health and dealing with pain.
The main thing I have learned in my time studying Systema is to focus on relationship with breathing while doing my aiki. Kokyu is in the principals of our art, but I simply had not encountered a teacher that focused on it before.
I suggest you embrace the breath. It is training. It is meditation. It is a simple way to control the tension in our system. While training I notice the people that quickly burn out hold their breath while performing actions.
Look to the other arts.
The Zen students focus on breath. Shooters, weight lifters, runners, swimmers, and child bearers all focus on the breath. We should too. I suggest breathing exercises friends. It has changed my art and my relationship with my body.
Funny thing about the word kokyu- the word's definition not only means breathing, but another definition is that is it the trick or secret of doing something. Makes me think there is more to this breathing thing in the arts after all.