This is probably going to turn into a rant at some point. Consider yourself warned. But I've been thinking about posting about what qi is, is not, and might be, for some time now.
First off, qi literally translates as energy. It is the term used in Chinese for all kinds of energy: electricity, wind, motion, etc. (Source: Yang Jwing Ming, since I don't speak the language myself). So someone saying that qi does not exist is apparently taking the Buddhist position that everything in the universe is illusion. ;^) Or, more likely, doesn't understand how broadly the term is applied.
Of course, mostly the deniers are decrying some of the more exorbitant claims made for qi as "life energy." And, yes, there are some real wackos out there. But, first and foremost, what else would you call the energy that keeps you alive? Sure, you can break it down into electrical, chemical and mechanical components, but taken as a whole, it might as well be called life energy. Some of the more practical, modern approaches have lumped qi in with bioelectricity and left it at that (Ken Cohen, for instance). My taiji teacher isn't convinced. I figure it's one possibility.
One of the goals of taiji is to learn to use the body to maximize qi-flow. What is involved in this? Opening the joints; relaxing; learning to move the body as a unit. When I am having a good day, I can, indeed, feel something flowing through me: heat, warmth, tingling. I don't particularly care if modern science wants to give these sensations a new name and tell me there's nothing mystical; this could very well be the case. I care when people claim that qi isn't real. You may as well claim that pain and emotions aren't real. I can feel it. When I follow the taiji recipe as closely as I am able, I can feel it more strongly. I can see/feel when other people have it. I cannot affect objects outside of my body using qi, however, and tend to be very skeptical of such claims.
So, think of it this way. Qi is a bodily sensation that indicates when the body is limber, relaxed, and alligned well enough to be martially effective. Someone with enough mastery can tell when another person has good qi-flow. It's more of a magnetic sensation, really, than anything I can see. That would fit if it is, in fact, bioelectricity.
Oh, and if it isn't obvious, be very suspicious of any devices, potions, etc, claimed to enhance qi-flow. The only way to get there is through work and practice. Hard work and continual practice. However, I do find that qi does seem to flow along the claimed Chinese energy meridians. Could be that that's where the sensory mechanisms are located, if nothing else. *shrugs*
AFTERTHOUGHT: The first qi exercise I ever encountered was actually from a televised yoga class. It's simple enough that anyone can try it. No clue what proportion of people will get results. Some people practice taiji for years before they feel qi. Others, like me, feel it almost right away. Anyway, the exercise:
Hold your hands in front of your body, like you're holding an invisible ball, maybe 8-12 inches in diameter (whatever's comfortable). Make sure that the palms face one another. Now, very very slowly, move the palms a bit closer together, then a bit further apart. It's very important to move SLOWLY so that you can feel any sensations that arise. You will get better results if your shoulders and arms are relaxed, with only enough tension to keep them from falling. Try it, if you like. (What I feel is printed lightly below; intentionally illegible unless you highlight it; I'd recommend trying the exercise yourself before you read it)
When I do this, I feel a sensation similar to playing with magnets. Pushing the hands together is like pushing the same poles together: there's resistance. But there's also resistance when pulling them apart. And, sometimes, tingling. The sensations get stronger the more I force my hands together, and weaker the more I pull them apart.
Inquire Further
Relinquish
