Breath is crucial for life. Physical respiration goes on as a largely unconscious process as the body exchanges oxygen and carbon dioxide to power the activities of every cell in our bodies. Deliberate deep breathing will ensure that we take in enough oxygen and can calm feelings of breathlessness or fear. Conscious breathing used as part of a spiritual practice focuses the mind's attention and helps relieve stress on our bodies.
~ from NAVIGATING THE TIDES OF CHANGE by David La Chapelle