Prānāyāma has been referred to in modern literature as ‘yogic breathing’. This is an attempt to differentiate breathing exercises as noted in the yogic texts from general breathwork. Yet the term ‘yogic breathing’ is unsatisfactory as it neither defines or accurately explains the nature of prānāyāma and instead implies some alternate obscure way of breathing. Ironically, prānāyāma correctly defined means ‘no breath’.

The earliest recorded definition of prānāyāma is from about the 4th century C.E., in the Patanjalayogashastra, a composite text considered the most comprehensive and systematic explanation on yoga, its mechanism and experience. It prescribes no doctrine but rather details the outcome of yoga, the necessary mental attributes, and different states of consciousness. Prānāyāma, as part of the mechanism of yoga, is a composite of two Sanskrit words: prāna + ayāma:
Prāna as detailed in the yoga sutras is clearly meant as the breath. Many interpreters extrapolate the meaning to include esoteric understandings of bodily and psychic energy, which some later texts make reference to. This is not the meaning Patanjali attributes in the Yoga Sutras.
Ayāma means to pause or extend. Patanjali describes four occasions when the breath pauses, either controlled or natural. The breath is paused and as a result a round of respiration is extended. This may lead to other subtle physiological and psychological consequences which to later interpretators becomes the subject of prāna but in this definition refers to the pause in breathing, essentially temporarily restraining the respiratory function.

Later teachings after the first millennium referred to a word ‘kumbhaka’ to denote the retention of the breath synonymous with prānāyāma . These Hatha yoga teachings form part of a comprehensive yoga practice. Their techniques, however, place emphasis on differentiation in the form of inhalation and exhalation while employing a retention after the inhale and only in certain cases after the exhale. These Hatha yoga kumbhakas include all the points detailed under breathing exercises in What are Breathing Exercises to be considered as the practice of prānāyāma with very specific direction on the inhale, retention, and exhale. Though related in essential quality to the definition of prānāyāma by Patanjali the subtle difference lies in the latter’s emphasis on the nature of no breath without any regard to the inhale and exhale. Patanjali allows for a forced approach, which is the training in Hatha yoga, but also allows for a passive approach whereby the pause in the breath, essentially a state of no breath, arises naturally. This is a transition from an engaged action to a mindful attention on the space between an inhalation and an exhalation, essentially the state of breath, almost no breath, in a meditative approach. Hatha yoga achieves the same outcome but prescribes several engaged and practiced breathing exercises with controlled retentions until a passive no breath stage becomes a natural meditative state of mind.