Excerpt from Inside Zhan Zhuang
"Now, since there are a number of different types of Chi, functioning throughout the body, how is it that the Chi can become unified? The answer to this is a little complex.
Basically, when we focus correctly within the low Dan Tien or navel area and do this repeatedly over a long period of time, we are able to bring more and more of our consciousness to bear, that is, more and more of our total beingness. This increase in the amount of consciousness we can focus eventually triggers a sort of chain reaction.
That is, it inevitably arouses and calls forth the all important pre-natal Chi from which all other types of the body’s Chi are derived. Note that this pre-birth Chi is literally drawn from the Ming Men, where it is stored, into the low Dan Tien."