https://www.scientificamerican.com/article/proper-breathing-brings-better-health/

As newborns, we enter the world by inhaling. In leaving, we exhale. (In fact, in many languages the word “exhale” is synonymous with “dying.”) Breathing is so central to life that it is no wonder humankind long ago noted its value not only to survival but to the functioning of the body and mind and began controlling it to improve well-being.

As early as the first millennium B.C., both the Tao religion of China and Hinduism placed importance on a “vital principle” that flows through the body, a kind of energy or internal breath, and viewed respiration as one of its manifestations. The Chinese call this energy qi, and Hindus call it prana (one of the key concepts of yoga).