APANA is one of the 5 main energy-streams in our body.
"The practices of hatha yoga trains apana to work efficiently—they help us conserve and redirect this energy so that we can access deeper planes of awareness.
By repurposing apana, we build a foundation from which we can awaken and intensify our inner spiritual fire...
With a little practice and awareness, almost all of the classical asanas can be done in a way that provides access to apana vayu; indeed, mobilizing apana in the pelvis and then redistributing it is one of the main goals of asana work. This engagement of apana is the intention behind mula bandha....the activation of apana anchors the body and allows for a smooth flow of energy from the root up through the spine."