Yoga is a symbolic practice.
The sun salutations are not just a series of forward folds and backbends that contract and flex our inner sun points (nabhi and surya marma (acupressure points) from diaphragm to belly button). They are also a ritual of gratitude for the Fire Element.
The Fire Element transforms everything that it touches. It's quite a magical thing. It can throw that which is hidden in darkness, shade and shadow into stark relief; melt away a body of the Water Element into an almost invisible steam that drifts away and disappears leaving the, now, bare ground dry and visible; it can transform non/less-edibles into delicious nourishing meals helping disparate ingredients meld together in a new form; it effects our digestion, mental health, hormones, eye-sight, metabolism and much more.
The lack of the Fire Element is no less astounding, sending animals into hibernation; halting growth of foods and beautiful lush natural forms; shorter, colder, darker grey days; longer nights; affects upon our drive, enthusiasm; a reduction in our ability to discern one object from another; a change in mood and sleep.
It's no wonder that these older traditions, sciences and philosophies such as Ayurveda and Yoga give so much time to explain - and gives thanks for - our relationship with our inner sun (agni/digestive power - the root of good health) and the outer sun.