If you’ve reached advanced levels and enjoy new challenge (Beware of Egofeed—hey look, I did a Lotus!) then check out Light on Yoga. Iyengar is a master of the art, and the pictures in the book illustrate his talent. They could also be discouraging for the beginner, so don’t worry about whether you’ll ever be that loose, just appreciate the incredible possibilities inherent in the human structure, and wonder why the rest of us don’t develop them. The book also has a superior introduction to the entire yogic philosophy.