Pranayama Evidence by Outcome: What Trials Found

Read this first

Pranayama is a set of yogic breathing practices from Indian traditions; see the overview of pranayama. It covers very different practices, from slow and gentle breathing to fast, forceful breathing and breath retention. Research often lumps them together, which makes results hard to apply to any one technique. A comparison of 73 studies against the traditional texts found that the way a given technique is practiced in research can differ from the texts. [1]

This page reports what was found; it is not advice to start or stop anything. Breathing practice is at most an add-on and should not replace medicines or medical care. If you feel dizzy, faint, tingly or short of breath during any breathing practice, stop and breathe normally. In the United States, call 911 for an emergency.

The overall picture

A systematic review of controlled trials of pranayama alone found 18 studies (13 randomized, one crossover) of 16 to 160 participants, lasting from 4 days to 6 months. [2] The authors reported benefits mostly in people with respiratory diseases such as asthma, and said "further high-quality randomized trials are required to provide definitive evidence." [2] That summary is typical: many small, short studies, with results that are encouraging but not firm.

Why trials of breathing practice have limits

• You cannot hide from people that they are breathing differently, so expectation may shape self-reported results such as stress or pain.
• Many trials compare pranayama with a waitlist or usual care, not with another calm activity. Time, attention and relaxation may then explain part of any benefit.
• Reviews often pool different techniques, so a result may not apply to any one of them.
• Harms are rarely tracked. A review of pranayama for mental disorders asked for better assessment of adverse events. [3]

Evidence by outcome

Two cautions on the table. First, the Cochrane asthma review covers all breathing exercises, and 14 of its 22 studies used yoga; it is not a pure pranayama result. [8] Second, the childhood asthma review framed breathing practice as an add-on to recommended drug treatment, [9] and none of the sources suggests changing inhalers or other medicines.

What physiological studies add

A systematic review of slow breathing (fewer than 10 breaths a minute) found 15 eligible studies out of 2,461 abstracts. It reported changes in heart-rate variability and brain activity, with feelings of comfort and relaxation, and fewer symptoms of arousal, anxiety and depression, in healthy people. [13] These are physiological findings, and the review was not limited to pranayama. They do not prove that a particular pranayama prevents or treats disease.

For fast and forceful techniques, studies mostly show short-term effects while the practice is happening, such as raised heart rate and sympathetic activity during bhastrika. [14] That is a physiological finding, not a health outcome. See bhastrika and kumbhaka and breath retention.

Bottom line

For slow, gentle pranayama, evidence for blood pressure, asthma quality of life and some mood outcomes is encouraging but limited by small trials, unblinded designs and risk of bias. For fast, forceful techniques and breath retention, there is little evidence of health benefit and few safety data. A gentle starting point is described in pranayama for beginners.