The yoga philosophy maintains that the breath is the most important facet of health, as the breath is the largest source of "prana," or life force, and hatha yoga uses "pranayama," which literally means the science or control of breathing.
The practice of pranayama helps the yogi get the maximum benefit from this life force, also known as prana.
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Galen believed in a vital energy or creative force that he called pneuma similar to the Ayurvedic " prana.
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