Hatha Yoga was given for the discipline of the human body, mind and emotion.
When practiced according to the teachings (never with a plastic mat)
one gains mastery/control over the lower laws, thus naturally abiding in One's True Nature, Spiritual Light.
Body Electronics and Yoga (Knowing ONEness) are integrally connected.
Being Perfectly Still
Breathing Deep and regular (consciously controlled)
Eating a light and healthy diet
Mastering emotions/mental discipline, all required before