What is qi?

[taai gihk yahn]

Heel breathing just mean a type of deep breathing which accord with the spine natural movement. One doesn't have to be cultivate man to practice it. In fact one practice it to cultivate.

yup; it's about breathing with the entire body - u start w respiratory diaphragm, then coordinate with pelvic; u engage the pedal diapraghms (one-half under each foot - the two feet arches when put together are shaped like the dome of the respiratory - this is the Subterranean Spring connection) by the way ground reaction force travels back up the body from when u engage the upper diaphragms - the "skill" is to learn to ride it so that you "float" the cranium and activate the cranial diaphragm (tentorium cerebelli) which stimulates the pituitary gland ("third eye") that sits in the sella tucica of the sphenoid bone, which "pumps" due to the movement of the dural membranes that u synchronize w the breath and ground reaction force; this is the physiological pathway for the Micro Cosmic Orbit; when u synchronize all of these systems, u experience various things, including lightness on top / rootedness on the bottom...

and BTW, u utilize one aspect of the cerebral spinal fluid "flow" rhythm (known to some as the "Long Tide") as a way of mediating / cooling any excess stimulation of sympathetic chain - which results in "heat" of "zhen qi" that Hendrick keeps going on and on about...

Btw, qigong is modern term coin by Liu GUI Jen in the 1950 of communist china. There is no such term in ancient china text.

that is correct;

good lord - we actually agree on both of these things...