Yoga and the body

In a book of Sri Aurobindo it says if one could permanently reside in the self or Natural State, the physical body's cells could transmute in light. In Buddhism this is known as Rainbow body and the teaching are very similar. Offcourse the body in practical terms wont change in this era but could it still transfom in a better vehicle if one remain in the self? WHen one resides in the self, the self itself gives energy to mind and body without any effort of our own? Thanks