I can't disprove UFO abductions either. guess the burden is on the person claiming it.
here are some questions to ask...
1. has anyone opened up a body and discovered meridian pathways? and don't say nerves and blood vessels, because if they were the same, then there would be no reason to distinguish the term 'meridian'.
2. has anyone been able to move things without touching them under test and observable conditions? If someone could do it, they have not stepped forward to collect the Randi prize.
3. Has anyone been able to demonstrate ANYTHING which a non-chi believer can't do? How many olympic athletes attribute their superior performance to chi-based training? If Chi can improve physical performance, then why don't we hear it being attributed to in all professional athletes? These guys are getting paid millions to be the best - they are constantly looking for anything to give edge...yet chi-based notions have never made it to center stage as something worthwhile to harness and incorporate in regular training? and if you can name a few athletes into CMA or TCM, then is their performance superior? if not, then theres not really anything that can be claimed.
points 1,2 &3 can't be disproven - I'm only saying that they have not be shown as apparent, therefore the most likely is that Chi-based training does not produce superior performance in any way shape or form other than perhaps feeling better about yourself and reaping placebo effect - which anyone else might equally get by praying to their beliefs, or simply believing in themselves.
The best case for Ki/Chi has been on the conceptual construct used as a visualization tool for learning complex body dynamics and optimization. I agree with that view. I can see how thinking in terms of a conceptual 'energy flow' can help deliver the lessons. however, there are other constructs for delivering the same lessons equally as well. it just depends on what best resonates with the particular student. If you don't believe me, look at Aikido schools of thought. There are Aikido groups which do not view ki as a spiritual or physical energy at all. The view it as a conceptual tool only. it's a sortof secular take on Aikido. Do those groups have less skill after the same amount of years than a true believer of supernatural ki based Aikido? I'd say however, that most Aikidoka seem to be somewhere in the middle of those two extreames.
What I discount, is the notion of Ki/Chi being a real physical force able to act and react to the physical world.
a conceptual thought cannot effect cancer cells any more than a wish and a prayer can make things so.
now, there is a acting psychology which produces a varied desired effect, called placebo. I'm not dicounting the benefits of placebo, nor do I know exactly the mechanisms that a person produces in order to achive those gains. Just because I can't explain it, doesn't mean I can jump to a conclusion that since it's unknown, it must be Chi flow. Why jump to that conclusion? maybe it's prayer that should be credited...maybe it's a chemical yet unknown that the body produces when the mind truely believes. who knows. How can it be evidence specifically accredited to Chi energy?
If this threads study was not slanted towards an outcome, then the study would include results of other belief systems side-by-side with ki. for instance does prayer affect cancer cells better or worse than ki? does Indian meditation? do people who are able to 'lay-on hands' in churches have results of affecting cancer cells? how do athletes fair? etc...
most studies that support TCM, seem to have some things in common:
- The funding and/or researcher have apparent agenda of supporting the case they seek to show.
- The study is done with an insufficient test base or non-blind tests.
- The affects shown as a benefit, do not take other factors into account. for instance, a study could easily show all sorts of health benefits in elders engaging in regular slow-moving tai-chi classes. people would say 'wow, there really is something to those CMA styles'. but then you compare the those benefits with another separate test elderly group engaging in very low impact square dancing...and it shows very similar health benefit results! duh, it's EXERCISE, ACTIVITY, SOCIAL MINGLING, etc which should be attributed...not the mysterious ancient chi healing force that companies paying for the slanted study want you to buy in to.
but you have to keep an open mind to see this. if you are already invested in a certain way of thinking, then I don't expect the giant leap it would take to view things in a larger scope.
plain and simple, in the larger picture, TCM is an industry. an industry survives with profits. profits are made with customers, customers are made by making them believers...and to make them returning customers, you need to get them addicted to pursuing the promises - which will deliver, but never above the level of placebo.
on the human side of it, before I'm accused of being mean.

If people in the end feel better or learn how to believe in themselves thru empowerment, real or imaginined, then it was treatment well spent.