The extent of its use and length of rest at each stage, when transiting from one category to another within our Āsana practice journey, was dependent on the facility of the practitioner and the intensity of the practice.
“Cale Vāte Calaṃ Cittam
As is the breath so is the mind.”
Within this individualised variance is the guiding principle that the role of Śavāsana is to facilitate a smooth transition for the flow of the breath and also the pulse through and beyond the Āsana practice as a marker for the practitioners state of mind.
However according to Desikachar the viniyoga of Śavāsana was seen in terms of recovery from the fatigue of the preceding aspect of the practice rather, than say recovery from the preceding aspects of ones life.