I read the article and felt that it was a bit extreme. Any exercise can wreck your body if you aren’t yet prepared for it or have done it to the point of getting overuse injuries (such as cardio on an elliptical or treadmill which have long been advocated by the AHA and other nonprofits, weightlifting, swimming, etc.). I agreed with Glenn Black’s statement that most individuals should be starting with ROM exercises rather than set poses, because I believe this would lessen many of the potential risks. Obviously folks that have a pre-existing condition or injury could have it exascerbated by trying moves that are beyond their ability. Progressive Overload is most effective when a client can begin with exercises that are safe and fairly comfortable.
I personally love taking yoga classes, although it is one of the practices I’m not yet certified in. I was recently encouraged by an article ACE ran on this very subject. If you’re interested it is in the February 2012 issue under “Hazardous Yoga”. Even if you’re not certified through ACE, you can view the newsletter for free on their website: www.ACEfitness.org under Fitness Professional Resources. In it you’ll find some of the more controversial poses, arguements for and against each pose, and alternative poses for people that want the benefits of said pose with fewer risks. Hope that helps!