I have been practicing the Bikram beginners series for about 10 years now, and the advanced series for about 8 years now, and competing in Yoga since 2006. While nothing can replace the medical benefits of the beginners series, in advanced class we get to have some really exploring the potential of our strength and flexibilty. It does require sound breath technique, alignment, eye focus, and muscle control in order to be practiced effectively and safely. Ideally we run through over 100 postures in 90 minutes.