Yoga X - What a Workout!

So, I did Yoga X earlier today, and let me tell you, I have a new respect for Yoga. The first 30 minutes or so of the workout are very intense. Your arms and legs will burn. This is my first experience with Yoga of any kind. I learned just how inflexible(stiff!) I am. I can really see how doing Yoga on a regular basis would be very beneficial healthwise and and improving your flexibility. I read in several forums how some people didn't like Yoga X and they substitute it for something else. But I'm definitely not gonna do that. The Yoga X workout definitely seems too beneficial to leave out.