The physiological effects of slow breathing in the healthy human
Although the effects of slow breathing in the healthy human have yet to be comprehensively reviewed the scientific studies discussed in this article show that the breathing pattern, as defined by respiratory rate, tidal volume, diaphragmatic activation, respiratory pauses and passive versus active expiration, has a profound effect not only on respiratory efficiency but also extending to cardiovascular function and autonomic function (i.e. the parasympathetic and sympathetic arms of the autonomic nervous system), where the effects are bidirectional.
Although not specifically reviewed nasal breathing is considered an important component of optimised respiration.
Slow breathing is achieved by 6 breaths per minute. It generally coincides with increased tidal volume and may enhance use of the diaphragm resulting in enhanced ventilation efficiency and arterial oxygenation.
Historically, both yogic breathing (pranyama) and Buteyko breathing have claimed success in treating a range of medical conditions including respiratory and circulatory diseases (treated by Buteyko breathing retraining). It is important to appreciate that Buteyko breathing retraining involves more than merely slow breathing.
It is also important to appreciate that this article discusses the physiological benefits of slow breathing in healthy humans whereas Buteyko breathing retraining is taught to the unhealthy human whose breathing is dysfunctional.