Re: Breathing and acid/alkaline balance
[This isn't original. Somehow two or three things I've read came together...]
Gentle, full exhalation empties the bottom of our lungs of gasses and guarantees that the following inhale will go to the bottom of our lungs.
I don't hold much with forcing the maximum filling of the lungs by stretching the upper portion. I prefer to gently correct my posture as a part of the focussed inhale. (I've been practicing my understanding of Alexander Techniques, and have added a lifting of the front rib cage and a lowering of the back.)
Tensing a group of muscles on the exhale brings a flood of oxygen to those muscles on the relaxing inhale, through the blood. (Some say that tension on the exhale helps that area to balance the fat and other substances stored there. In other words we can lose weight in that area!)
I feel this last exercise helped a very bad injury to a bundle of muscles on my shin. I couldn't tense the injured area, so I tensed, flexed, and stretched the toes, foot, and ankle, on the exhale, instead. I felt that the blood had to pass the injury on its way into the foot, and would, therefore, benefit the damaged area.
(While I'm on the subject, the physical healing stages the leg went through, automaticaly, were amazing to watch. And the adjustments I needed to make in activity, whole body re-strengthening, and posture were a revelation. Healing goes on for a much longer time than I ever expected. Perhaps we even retain differences in our movements, forever.)
Does any of this help you?
fledgling