Effect of breathwork on stress and mental health: A meta-analysis of RCTs
nature.comI’ve been doing O2 and CO2 “tables” which are breath hold exercises for free diving. For co2 you hold for 2 mins, breathe for 2, hold for 2, breathe for 1:45, hold for 2, breathe for 1:30 and keep reducing the breathing until you’re at 15 seconds. It’s getting you used to co2 building up. Much more to it than that but the feeling during and after is incredible. Been doing yoga for 6 years and never had a feeling of calm like this. Check out STAmina if you’re interested which is a free diving training app. Even integrates with pulse oximeters. And free diving itself is awesome and becoming very popular.
So, this might be a stupid question. I am asking it honestly, though.
Speaking as someone who has sleep apnea, my doctors have really hammered home how bad apnea events are for my general health. Does that not apply to this kind of training?
Apnea is bad because it kills long deep REM cycles that are essential for your body’s recovery.
I don’t think that’s the whole story, or even the most important part. My understanding is that blood pressure rises significantly during an apnea event and that over time this can cause all sorts of physical problems, especially blood vessel damage, leading to increased risk of heart attack and stroke.
I’d guess that lack of REM would cause symptoms like daytime drowsiness, but it’s the physiological effects that are gonna kill ya.
Maybe but, correct me if I’m wrong, temporary high blood pressure isn’t really harmful.
My understanding is that bad sleep will induce chronic stress and chronic stress will induce high blood pressure.
So yes, bad sleep will dangerously increase blood pressure but it’s not a direct effect.
(That’s my interpretation, maybe it’s false)
It’s physically harmful in the long term, can lead to serious vascular problems if left untreated.
In fact it turns out that REM sleep can sometimes compensate for apnea in some people, that is, the onset of REM can happen more quickly. Some people can get enough REM sleep even with apnea.
To be clear, ultimately all of these things can become problems, I’m just disputing that lost REM is the main health concern. It’s one concern, but AFAIK, in the long term venous damage is what will kill you.
This is fundamentally the problem.
To expand / clarify slightly: REM sleep is absolutely essential to "higher animals". It is not, though, "deep sleep" in the sense that "long slow delta wave" sleep is often called "deep sleep", and the "NREM" stages of sleep tend to be "deeper" (in the sense of physiology 'slower' / harder to awaken) than REM sleep.
This Wikipedia article could use some editing, at least for clarity, but is certainly a solid enough reference and starting point for further reading (for anyone interested): https://en.wikipedia.org/wiki/Sleep_cycle
Apnea is incredibly stressful on the body / mind. Disruption before REACHING REM sleep (one of the reasons REM may be referred to as "deep sleep" in non-technical language) is among the worst of the effects. Since most of a single cycle is NOT REM sleep but rather stages occurring before REM, REM is a phase most often prevented by episodes of apnea. But, the physiological stress also relates to disruption of other phases as well.
Besides sometimes profound effects on cognitive function varying over days and weeks depending on the severity / frequency of "apneic events", the stresses that accumulate over time tend to cause cardiovascular problems, especially.
As usual, sites like Cleveland Clinic's and Mayo Clinic's etc. give good info (short of the more technical scientific review articles you can search for on PubMed, for example). Cleveland Clinic's seems quite good to me (perhaps a bit better in clarity regarding phases of sleep than the Wikipedia article, as well):
https://my.clevelandclinic.org/health/diseases/8718-sleep-ap...
Edit: you wrote "long deep REM cycles" - that's a reasonable phrasing and would also 'frame' effects overall. So, if it's unclear from my writing (ha, write after I 'dinged' a Wikipedia article), there is no conflict (depending on exactly how one reads these messages, of course) between my message and the parent. To clarify, it was not my intention to come off that way (but I see that certain emphases might suggest that, apologies if it reads that way to some!)
I had similar exercises when swimming: 4x25m with 3 breaths each 25m, 4x25m with 2 breaths each 25m, 4x25m with 1 breath each 25m, and 4x25m where you only breath when you hit the wall and turn. There are similar variants for 50m.
That made a huge difference expanding my lung capacity, and I still have most of that expanded lung capacity today.
+1 for Stamina, I use this app for apnea training for surfing. Wim Hof also produces a similar calming feeling, there are some good guided Wim Hof videos on youtube that are easy to follow.
Are there any videos in particular that you can recommend?
Here is a good one guided by Wim Hof himself: https://youtu.be/tybOi4hjZFQ?si
It’s probably your brain about to tap out but you have this dizzy feeling of being “calm”
Lol I’m wearing a pulse oximeter and it never drops below 90%
at 90% you're bordering on sever hypoxia, I would not recommend this for the general public
"I would recommend you to hold your breath until your SpO2 drops to 90%." ... I mean, who would say such a thing, right? :D
But I totally recommend breathwork ... to myself and I don't even wear a pulseoximeter.
Never did join that club.
So the results from all studies are based on self-reported stress, studies may include other non-breathing related interventions, the breathwork intervention can comprise any number of kinds of breathwork, and authors themselves conclude that the studies included are at a “moderate” risk of bias?
Seems hard to say anything substantive about the conclusions when the inputs are that shaky.
4-7-8 breathing has origins in Pranayama FWIU?
"Effects of sleep deprivation and 4-7-8 breathing control on heart rate variability, blood pressure, blood glucose, and endothelial function in healthy young adults" (2022) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9277512/ https://scholar.google.com/scholar?hl=en&as_sdt=0%2C47&q=Eff...
Pranayama: https://en.wikipedia.org/wiki/Pranayama
Yeah it's somewhat of a more broad term though? Like, the freakiest pranayama gets is rechaka pranayama, where you breathe out the air from your lungs and try to hold it out, depleting your blood-oxygen levels (hypoxia mimesis). Has also been practiced in qigong[1], thankfully you can't actually induce self-unconsciousness this way (at least not without, say, breathing into a bag[2]). But all to say that my understanding is that pranayama is just kind of yoga slang for "breathwork", there's not just one kind of it as far as I know?
1. https://www.pacificcollege.edu/news/blog/2020/03/26/the-link... 2. https://pubmed.ncbi.nlm.nih.gov/17324641/
Anybody has done breathwork naturally without even knowing about its existence? I didn't know any of this (had 0 interest in the body/yoga/meditation before) and I used to do this pattern of deeply inhaling slowly and holding until I can't really anymore, then slowly exhaling. Then repeating for a few times. Very relaxing. Although I know about breathwork a bit more now and the different patterns, I am not sure if this practice has a name (but I wouldn't be surprised to find out if so).
I've been aware of breathwork since I was a teenager, but I always look for easy actions, with low barriers:
Watching my resting dog breathe I noticed he inhaled slowly and exhaled without much apparent control, just relaxing and letting it all huff out, then pausing awhile before the next inhalation; I tried this, it feels good, so I keep doing it when I want to feel more calm.
From reading Breath, by James Nestor, I learned that a good target for calm-inducing breathing is about eleven seconds for an inhale/exhale pair, common with many religious activities like chants, etc. Breathing like my dog, I aim for five seconds in, ~three out (not counting, just letting it out), and as long a pause as feels right, sometimes pushing myself a little to extend.
I’m no expert on meta-analyses, but if the total pooled samples is 785 and there are 12 studies. That seems like quite a small average sample size per study. Is this not underpowered? An average of junk is still junk.
Small individual study sample size does not necessarily mean junk. Junk is a product of poor methodology. The main concern with sample sizes may be overestimates of effects if the event is rare, or poor precision (ie large confidence intervals).
However you’re right to presume that small studies are likely to be lower quality, often because they’r observational as opposed to randomized studies.
A true control seems impossible for any "breathwork" study; anyone doing regimented breathing knows that they are doing something. And placebos work, whether you believe in them or not (say the studies ...)
If you can't show that a specific breathing exercise is somehow better than an essentially random breathing exercise, then it doesn't matter what kind of breathing exercises you do.
If you can't show that a breathing exercise is better than e.g. same time spent on stretching, then there's not much point in doing (separate) breathing exercises at all.
Papers should really come with a “jump to discussion/result” link
Its called the abstract. And its the first section of every official paper.
Right at the end of the abstract:
> Overall, results showed that breathwork may be effective for improving stress and mental health. However, we urge caution and advocate for nuanced research approaches with low risk-of-bias study designs to avoid a miscalibration between hype and evidence.
> However, we urge caution and advocate for nuanced research approaches with low risk-of-bias study designs to avoid a miscalibration between hype and evidence.
It's interesting to think about the information conveyed by this sentence.
Would anyone seriously propose non-nuanced research approach with high risk of bias that easily confuses hype for evidence?
Yes, all the time. Every time anyone posts a comment here or reads an article to form a opinion, without instituting a blind study behind it, they are deciding to proceed without nuanced research. The point is that in doing so we are at risk of confusing hype for evidence.
As in the abstract here, often the signal comes just as much from the fact that something needs to be said at all - not just the content of what is said
No, I agree with the original commenter.
It's about reading the full discussion section to understand it in nuance, see the caveats etc.
It's not about a summary -- it's about skipping the intro that reviews the literature you already know, the method, all the tables of results, and jumping to the actual good stuff.
I frequently find myself scrolling to get to that part, overshooting, scrolling back...
Also literally has a link to "conclusions" :)
I propose we call this the tl;dr
I like it but maybe we need a non-abbreviation, maybe we could call it something like “abstract” or “executive summary” depending whether our audience is academic or commercial.
It could be like a summary of what follows. Oh, and what about like a SUPER short summary above that, like just one sentence about what its about, call it like a, "leader" or "header" or something like that?
Ohhh, love it! Like books have titles!
Is the estimated effect size (g=-0.35) -35%? That feels a bit high to me.
Cohen's d and Hedges' g shouldn't be interpreted as the size of the change in scores, but rather how the distribution is shifted. A score of .35 is considered a "low to moderate" effect.
Effect size g is in units relative to variation. It's a corrected version of Cohen's d for cases of unequal variance between groups.
> Overall, results showed that breathwork may be effective for improving stress and mental health. However, we urge caution and advocate for nuanced research approaches with low risk-of-bias study designs to avoid a miscalibration between hype and evidence.
So after searching through 1325 papers and systematically summarizing 12 randomized controlled trials, this is the result? This has kept multiple professors busy for months and all we learned is "breathwork may be effective"?
It doesn't matter anyway. The professors have a Nature publication and Nature has some readers. Everybody happy.
It's a pretty strong message that the effect has not been proven. I was personally under the opposite assumption, having seen reporting on some of the earlier research.
> It's a pretty strong message that the effect has not been proven.
The message is that the effect has (may have) been proven since "showing breathwork was associated with lower levels of stress than control conditions".
They can't rule out the effect, but it might still just be placebo and/or unrelated to breathing (or it might be a statistical fluke).
That kind of innate skeptism is good science though.