Yoga is a beautiful thing in a way in that it’s so free-form, and the spirit of yoga is anti-regulation. But in that, there is tremendous abuse and a huge range. The Iyangar school requires a minimum of two years of study before they will certify a teacher. But it’s the Wild West of yoga training out there. You don’t even have to go to a studio to get a certification. You can do it online. Now, probably most yoga teachers have had some in-studio certification, but the minimum training is 200 hours. That’s not a whole lot. It’s a very minimal requirement and in that, in the inexperienced nature of some of these teachers, I think that’s where you find some of the biggest dangers in yoga and the biggest dangers of injury.
— William J. Broad on yoga’s certification requirements.