What is often thought of as chi is sometimes a residual effect. The electromagnetic principals that are sometimes measured can be produced from different sources. One of those source appears to be a generation of a type motion that moves through the body leaving a trace in certain spectral ranges that can be detected. Often referred to as an aura.

Chi itself is a general word having many meanings much like the word energy, it often becomes a catch all word for different phenomena

The breath intermixing with the nourishment replenishing the body can be manipulated and some Qigong concepts work with these issues however those are physical things and the interaction of those physical things can be accountable and replicated and the results measured.
The mystery element either energy at minute levels or the life force itself would exist in and effect all of the 4 realms of power.

The ability to use chi in martial arts as described I agree with, but the way it is developed is not absolute.
The development process is a varied process other cultures have developed other methods of discovery development and application.

Interesting thread

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