The meditation that many people first come across is the deceptively simple one of focusing on the breath as it moves in and out of the nostrils.
The benefits can accrue fairly quickly: awareness of how much the mind chatters, increasing calm and the growing realisation that if we’re not our thoughts then what are we?
But there are any number of more complex yogic breathing practices with any number of physiological and clinical effects, with associated scientific literature handily reviewed in a 2018 paper in Journal of Ayurveda and Integrative Medicine.
The authors, at India’s S-VYASA University, quote unnamed ‘ancient texts on yoga’ as saying, “As the breath moves, so does the mind, and mind ceases to move as the breath is stopped.”
The line reminded me of an observation made by a kundalini yoga teacher in a past class: that things got interesting at the moment between the out-breath and the in-breath.
There’s a lot of ground to cover – 68 studies from a longlist of 1400, though we won’t cover all of them – so this will run over a few weeks.
Neurocognitive effects
Two studies looked at the impact of rapid bhastrika breath on reaction time, finding a reduction in anticipatory response after 18 minutes of practice; and a significant reduction in visual reaction after nine rounds of practice in schoolchildren.
Single and alternate nostril breathing
Nostril breathing is an important one, as it’s said to direct energy flow through the subtle nadi channels – right nostril for pingala nadi and left for ida nadi.
One trial on patients with hypertension compared the effects of nadishuddi pranayama with breath awareness in 10-minute sessions. There were reductions in systolic and diastolic blood pressure and an improvement in a test measuring manual dexterity and eye-hand co-ordination.
Single-nostril breathing for 10 weeks eased anxiety in 11 post-stroke cases, and helped language abilities in two separate group with post-stroke aphasia.
While many of these trials are on groups too small to draw firm conclusions – isn’t that right, Bart?
The sheer volume of them indicates that something – many things – interesting is happening.
The heart rate of eight volunteers rose after right-nostril breathing, which activates the “fight or flight” sympathetic nervous system. Another group found the “chill” parasympathetic system triggered after left-nostril breathing, using a measure called heart-rate variability.
Further data supporting the differences between left and right nostril breathing – ever wake up in the night and realise one nostril is completely closed off – came from a study on 20 “experienced subjects”.
After nine rounds of nadishuddi, left nostril and left initiated breathing, blood pressure and heart rate – parasympathetic side – fell.
After right nostril and right initiated breathing, blood pressure and heart rate rose.
There were no changes with normal breathing.
A pilot study in 2004 evaluated the effect of very slow breathing against a claim it could “eliminate and prevent heart attacks”.
How slow, you ask? Is one breath a minute for 31 minutes slow enough? (The review paper cited this as 20 minutes. Mistakes happen.)
This Wim Hof-esque feat was achieved with 20 seconds of inhalation, holding for 20 seconds, exhaling for 20 seconds, repeated 30 times. Go on, give it a try.
Fourteen different parameters were measured in the four subjects. Remarkably, all 14 saw “dramatic shifts”, with study authors reporting the technique (deep breath) “can produce unique changes in the post-exercise resting period after long-term practice that appears to have a unique effect on the brain stem cardiorespiratory centre regulating the Mayer wave (0.1-0.01Hz) patterns of the cardiovascular system”.
Next week: more yogic breathing, including testing its effects on pulmonary function in competitive swimmers.