nexus, plasticsquirrel - So, maybe Daoism and qigong are the real keys to longevity, not taijiquan. Or perhaps a balance of the two. Because there is a difference. Taijiquan does involve the expenditure of energy, at least from a sheer physical standpoint. Whereas Daoism and qigong are more focused on the collection and absorption of energy. Although, I'm sure there's some crossover in there. So perhaps you need both - to intake energy and expel toxins/wastes.

Point is, much of the longevity claims are anecdotal, and there are many examples both one way or the other. What they really need to do is take some large samples and then draw some statistical correlations, if any. And being careful to identify and isolate ALL factors, like diet, lifestyle, other practices (e.g. - Daoism, qigong, etc.), relationships, family genetic history, etc...

Is it even possible to really extend a possibly genetically-predetermined life? Or to just live a healthier life? I don't think this question has really been scientifically answered here yet