I keep noticing similarities between Yoga and modern fitness training. It's interesting when you see an ancient practice that has already got things that scientific people have only recently figured out. In particular I'm thinking about the way stretches in Yoga are done rhythmically, and with generally with muscular opposition. This is opposed to the stupid old way that people stretch which is just passive stretching. Yoga is a lot like "PNF" stretching, which is one of the new ways that modern understanding advocates stretching. There's a great link on my fitness page about modern stretching technique.
So, it's interesting when these ancient practices that don't really understand the science have come up with the right answer over time through trial and error. You see it a lot in cooking too, trying to figure out the science of how to logically cook things rarely works, and if you just copy what the French worked out over hundreds of years you'll probably be better off. On the other hand I think it's dangerous to look at these examples and assume everything they're doing is right.
It actually reminds me a lot of how species evolve. You'll see these adaptations happen over time that just makes them amazingly perfectly suited to their environment, but then there also be totally random bizzaro adaptations that don't help at all. I think all these sort of ancient practices are similarly, 50% of the practice really doesn't make sense.