Breathing--Mind and Body Exercise?

I’m always thinking that every type of exercise might have something to offer to my own training. So, without turning into a yogi or anything, what kind of effects can breathing exercises produce for both the mind and body. Pavel mentions breathing in his books, and Furey quotes Farmer Burns as saying something like breathing can make a weak man strong, something like that. So, could any really open-minded strength coaches (hint, hint, Davies and King) tell me if breathing should be something to look into. And if so, how should it be included in a program.

you mentioned two coaches (Pavel & Matt) who both have written a great deal of this topic. I am in complete agreement with breathing techniques empowering you. It is an extremely difficult topic to express as opposed to in-person but I am always interested in helping. In faith, Coach Davies

Being the worst skeptic, I decided to give breathing exercises a try. I back against the wall so that my lower back is completely flat. Inhale a little below maximum, force air out with mouth barely open, at almost total exhale, force out the last bit HARD, contracting all ab muscles. Breathe normally a few times, then at maximum exhale, WITHOUT INHALING, try to suck your bely button to your spine while lifting your rib cage as high as possible. I did about 5 reps, 1 rep being 1 of each, and today my abs are scorched. I did have fun with it and with the forced exhale, focused on a mild rotation, heavily contracting my obliques. Hell I am going to try these throughout the day and will note the change. BTW, I made no other changes to routine nor diet. I may become a believer if todays DOMS are any indication of affect.