In yoga, we usually breathe through the nose. But why do teachers insist on this point?
When we inhale through the nose, the air enters through the nostrils and then pass through the nasal mucous membranes, inside which there are dozens of small hairs, like eyelashes. They filter the air to prevent impurities from entering the body, and warm it up, saving us energy to then assimilate it. Breathing through the nose has thus the effect of purifying the air we breathe and putting it at body temperature.
The passage of air through this natural “filter” also has the effect of slowing down the flow of air (the mucous membranes and the hairs offering resistance to the passage of air). This naturally makes it possible to lengthen the duration of inspiration like that of expiration. And as in yoga, especially in our modern world, we seek to “slow down”, especially the breath, breathing through the nose is one of the tools allowing us to achieve this end.
Try a few seconds, focus your attention on your breath … Maybe you feel the passage of fresh air at the entrance into the nostrils? It coming out at a different temperature?