Hatha yoga has a practice technique called flow yoga. It comes from the traditional Ashtanga yoga. Ashtanga yoga sets high standards for asana practice since it is a scientifically rigorous methodology. You can only study the intermediate sequence once you have mastered the primary sequence. Can you go to the advanced series after you have mastered the intermediate one? About ten or so years after Ashtanga Yoga was first brought to the West, it was deftly altered and simplified. There have been unprecedented developments in Hatha Vinyasa Flow Yoga, DYNAMIC yoga, Power yoga, etc.