Why do many traditions speak of the 'breath' as being very important?

Because of the constant pressure of stress in our inner and outer lives, many of us do not breathe naturally. We have become upper chest breathers. This causes us to breathe faster than we should, often bringing about a chronic state of hyperventilation, a state in which we breathe too fast for the real demands of the situation. Those of us who breathe too fast often find ourselves holding our breath in moments of stress and fear. This is a natural momentary response to the presence of danger (it often signals the beginning the "fight or flight" reflex, a reflex which we especially needed in our early history on this earth). In a society in which stress has become the norm, however, our fight or flight response in turned on many hours each day, and we find ourselves either breathing very fast or holding our breath. In addition, since childhood,we've learned to use breathing to cut ourselves off from uncomfortable feelings and sensations. By breathing less, in more-shallow way-- we generally feel less. Another important factor is the growing lack of daily exercise, stretching, movement, and so on, in our daily life. Many of us sit more or less immobile at desks for many hours each day. This gradually conditions our breathing to a very narrow range of movement. Still another factor is the prevailing image of the hard, flat belly that we see in fashion magazines and health clubs. To be sure, the belly needs to be strong, but it also needs to be flexible for deep, natural breathing.