Yogic breathing - pranayama
In yogic breathing the brain and the extremities of the body remain passive and only the lungs are activated. We need to cultivate the role of diaphragm, ribs, intercostal muscles and abdomen which link and integrates the body and mind so we have a proper energy and blood supply without straining the nervous system.
We must relearn to not being in a mental activity of grasping breath or an idea with this practice as only a bare minimum of result will take place and less energy will be absorbed.
We will be learning to release the diaphragm as it is the medium between the physiological and mental sheaths and in consequence tightens as it records stress and tensions that occur in daily life
Page 74/75 Light on Life by Iyengar