Here is a superb scholarly description of jindan. It is a preview of an essay by the dearly departed queen of Daoist studies Isabelle Robinet (very thoughtfully translated by Fabrizio Pregadio).
As you can see, internal martial arts are simply the application of jindan to martial skills. I am using different language than Robinet to say the same thing. Basically, once you create the correct order of perception-action then you start reversing things.
Here is a list of some of the things we might think about reversing.Read More