I used to laugh at yoga but a posh (or pretentious) hot yoga studio was located by my old place and I got some free classes. Holy shit. Great way to meet some hot bitches. And the yoga wasn't too bad either.
First few classes are pretty humbling, like doing 15-20lb dumbbells at the end of a workout. Went for a couple of months and wished I had kept it up. I did it just for the flexibility at first but I honestly felt a lot healthier in hindsight. I don't think it should be written off as a fad. It's some good shit if you can commit to it.