Yoga is not any process, technique or formula for health and fitness. That may come and does come as one of the fall outs of the yoga, but that is not the central thing. Methods and techniques are at best just preparations for the yoga.  Yoga unfolds the true possibilities of our life. Nature, though derived from divine reality, covers the possibility as man is not ready yet; nature takes him through a range of experiences through many lives to prepare him. Yoga accelerates the process, not only of the individual but also of the collective life of humanity.