all we have to do is show that Chinese seniors who do tai chi live longer, happier and healthier than Okinawan senior folk art dancers...or American seniors who swim regularly for that matter. I certianly am not claiming I can put that together.
It would be a difficult task to separate out the life styles and cultural differences, not to mention diet and poverty levels of each in order to isolate and compare the benefits of each activity. I mean, it's easy to say that Okinawans historically live longer than Chinese (which is true), but it's a leap to say that okinawan folk dancing therefore must have more health benefit (which is not necessarily true).
I don't know for sure which activity benefits health best...however, I DO know that physical activity benefits health comparred to no activity. It's my opinion that the difference between any activity vs. no activity is much much greater than the difference between whichever particular activity.
let's pretend we had the numbers and saw that some activity/exercise added 10 years of life on average.
then let's say we comparred tai chi with folk dancing and found tai chi adds, on average, 1 month more than the average folk dancers life....and further found that other physical activities were within similar.
a 10 year difference is significant, whereas a 1 month difference is not. That's a made-up example, but that's what I'm thinking.
similar to how you can't really compare in a question such as: 'which religion is the best for happyiness'. that question is unanswerable, but everyone has their own sense as to what the answer is.
It's my opinion that someone who swims everyday for 50 years will be healthier/stronger than someone who does tai chi everyday for 50 years. The happiness factor is perhaps connected, but a separate and more subjective measure.