The demand and expectation of the fitness industry to keep the body moving non-stop with greater and greater intensity has become hard-wired. It's no surprise because that's how society is. Just keep going, going, goal-ing. Complete your tasks and stay on track because we all have to show how productive we are and prove our outer worth -- regardless how one is feeling or sensing, what one is intuiting or perceiving, or what emotions are arising -- let alone in need of release. The inner has so little value. It's no wonder some have difficulty staying still or silent, with just their breath to observe.
There are so many physical benefits to yoga, but obsessing over them is not the point. We treat the body the way an accomplished musician treats an instrument. A musician doesn't just hit keys or strum strings, he or she is listening to the sounds arising, listening to perceptions and feelings so as to play music and song. The body is our instrument, our tool for experiencing and expressing the soul.