Muay Thai shouldn't be confused with Tae Kwon Do. Not all Thai boxers thrash their bodies to smithereens when they're young. Many take care of themselves and are teaching in their late 60s. I think that many Westerners regard Thailand as this hick outpost in which the yokels will buy almost anything. I went to many yoga schools - all of them owned by ex-pat Westerners - that taught pathetic amalgams of New Age hippie dance, bad physical therapy and warmed-over bullshit. Come to think of that, you can find that in India, too, particularly among Indians "trained" by America's princess of pseudo-yoga, Shiva Rea. It's hard to fake Muay Thai in Thailand, though.
I'm with Matt. My money's on the Thai boxer.