Because I have no deep knowledge of Chi and other theoretical concepts in the realm of spirituality ...
Life force energy is not a "concept in the realm of spirituality". It is a very real and physical force, just like gravity - which is also invisible but very real. It's what makes you and I and trees and bears different than rocks, Wolfgang.
You don't need to be interested in spirituality at all to work with physical or mental chi. I've yet to meet a sensei (master/teacher of martial arts like Karate) who qualifies for sainthood. Physical and mental life-force energy or chi is the driving force behind accomplishments like chopping a cement block in half with one blow from a bare hand.
Martial artists generate a surcharge of physical life-force energy first (through exercise), then direct that energy toward their goal using simply will and intent. All that's required to chop a cement block in half with your bare hand is a reasonably healthy physique and a highly trained, disciplined and focused mind. Plus the willingness to work with an invisible force like life-force energy, of course.
But in order to work with spiritual life-force energy - which is infinitely more powerful than the physical or mental "voltages" - one is required to work on personal spiritual development, not just physical or mental.
I never would even try to correct you or Two Bears or whoever when you speak about Chi. I never would make a statement like 'Chi cannot explain...' because I do not know enough
Well good for you, Wolfgang! I do know that science has yet to produce the methods or technology necessary for studying life-force energy of any "voltage" level - physical, mental or spiritual. If such a technology had been developed and approved by scientific community, we wouldn't be having this discussion, would we?