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Dr Yang explains the embryonic breathing fully in DVD. Understanding and practising this kind of breathing gives me so much power to circulate the chi (pulsation) around my micro-cosmic orbit (small circulation) - I guess that you need to be good with belly breathing before you start this, in my case I was and now I can feel much stronger pulsation or the energy around the orbit, I would do 5 star.
As I progress in future I shall add or update this review.