Iyengar does not seem to have understood what pranayama, he is lost in a maze of rather strange explanations, practical cut in stages which recopy a lot of times, it loses in postures, anatomy the "breathing", but once you pass the technical one always remains on the outer form and thus our hunger ... No work on the centers, no inner vision, one speaks of fingers, brain, legs, arms but nothing about the nadis, nothing on the chakras affected by pranayama ... Finally, if you read the Upanishads Yoga, such as Yoga Tattva Upanishad, the goal of pranayama is obvious is not reaching the breath Kevala kumbhaka, gateway to the inner Yoga, Iyengar but unfortunately totally set aside this aspect ... But damage to the South Yoga image always outside and not too deep ... We stay in shape, in body and in jubilation ...