Decreased CO2 during breathwork: emergence of altered states of consciousness
162 comments
·April 15, 2025dluan
underdeserver
For someone with no connection to surfing at all, could you elaborate? Why is surfing special, or different from other sports, in needing to control your breathing?
zemvpferreira
Because panicking when you're being rag-dolled by even smallish waves can kill you, let alone waves of consequence. I don't have the words to describe what it feels like to be pushed to the bottom of the ocean by a wave, then just as you feel like you're running out of air be pushed back down by the next wave, and the next wave. You have no idea which direction is up and which is down, or how long it's been since you stopped breathing. 30 seconds will feel like death if you're not properly trained. Your very large very stiff board will be tumbling with you and could knock you unconscious or split your head open at any time.
My girlfriend got to be a decent surfer (~5 years practice and a former competitive swimmer) but never invested in learning the ocean. In 2018 she went out in a break she didn't know, in conditions above her league. Nothing too big (maybe 5 feet) but strong and relentless. Conclusion: She got sucked into the washing machine during a set and nearly drowned. Had to have the water beaten out of her lungs to restart breathing. Now she has panic attacks just getting into a flat ocean for a swim.
The sea is no joke. I encourage everyone to try surfing, it's a great hobby. But less than 10% of it is riding waves.
patall
Or just join the foiling community and go 40% wave riding. 80+% if pure down winding. Entree is a little more expensive but you save on not having to travel exotic locations (or not at all).
metalman
"the sea is no joke" trvth I was blessed with "over" sized lungs, and like swimming underwater, and hiking in mountains, so have enjoyed bieng able to do those things with minimal effort. When living in a city, I swam in an olympic size pool, and can go two lengths? (back and forth once+) undewater , but have no idea of how this actualy compares to an average. Got into doing the ?wim hoffman? breathing and like that, but have never noticed any altered conciousness, but that might be because my lungs are so large that I will need to realy realy push it? dont know, but after a car accident I was xrayed, and they were very surprised that the xrays, had to be redone, in two parts, as my lungs dont fit on a standard xray. I sing, and can hold a low note for a long time, and am kind of loud and boomy, unless I am carefull, which is a down side, as it is alarming for people in enclosed spaces. So breath work from the perspective of fine controll and exploring actual true limits, is something that is suddenly, looking like a good idea, for me. consiousness and all that
Davidzheng
Not the most convincing advertisement
FrojoS
You can somewhat simulate it yourself.
Lie down, do a push up, then jump up to your feet, upright, arms raised (Burpee). Repeat in rapid succession twelve times, then immediately shut your mouth and close your nose with your hand. Hold it. Close your eyes and imagine you are under water and don‘t know how long it will take till you can resurface.
You will feel an immediate urge to breath, a very unpleasant feeling in your throat, nose, ears, etc, and an immediate feeling of panic. That feeling is AFAIK caused by heightened CO2 levels [1].
Imagine trying to fight your way to the surface, in a panic, but the turbulence of the wave is too strong and keeps you down. Instead you have to accept the feeling of panic without acting on it, converse your energy while being rag dolled and pounded, trying not to dislocate your joints, keep or regain your sense of orientation, and wait for the moment that the turbulence subsides to the point it is possible to surface again.
You have little control over when that moment finally comes. And while seconds start to feel like eternities you might start telling yourself to never go surfing again. As time drags on, your resolve increases, to the point you might act on it once, and if, you finally resurface.
[1] I have no expertise but this is what I was told and this source seems to somewhat confirm https://pmc.ncbi.nlm.nih.gov/articles/PMC3138667/#:~:text=In...
cbogie
> Lie down, do a push up, then jump up to your feet, upright, arms raised (Burpee). Repeat in rapid succession twelve times, then immediately shut your mouth and close your nose with your hand. Hold it. Close your eyes and imagine you are under water and don‘t know how long it will take till you can resurface.
you forget, ‘put a blindfold on and tie your leg to a doberman’s leash then fall down 3-6 flights of stairs’
pretty similar forces and sensory at play, or at least a similar thrashing to big Teahupo’o over a sharp reef.
OsrsNeedsf2P
You can get hit by multiple waves in succession while surfing, preventing you from breathing for up to a minute. If you're at 180bpm and not breathing for a minute, you won't be coming back up
timewizard
If I need to hold my breath underwater for a longer period of time I'll hyperventilate on the surface just a little before diving. In my experience your lungs don't "burn" as quickly and so you can dive a little longer.
nikitoci
It’s dangerous, since hyperventilating removes co2 from your blood, and raised co2 level is primary trigger for the urge to breathe reflex. It may feel better to hyperventilate and dive longer but you’re risking suddenly blacking out. I’m a free diver and this is one of the first things you are trained not to do, as well as never to dive alone, for safety reasons.
sergioisidoro
Personal anecdote: I do freediving, so CO2 tolerance training is common, and I've done it on and off. Basically you do breath holds to train your body to get used to high leves of CO2.
I've found that brief high C02 levels are very good for activation, and to get out of a lethargic state. I don't know if a mix of cortisol and vasoconstriction and dive reflex triggered by the CO2, but I feel like it's a tool I have on my toolbox whenever I need to so something difficult or that requires a lot of will power.
It's not for everyone tho, because many people can't get past the initial urge to breathe, and would probably freak out with the first involuntary contraction.
Azrael3000
I also tend to use my freediving experience for the opposite, when I'm highly stressed I tend to do one or two short (full exhale) breath holds to calm down. This works amazingly quickly and let's me refocus. Note, this will probably not work for untrained individuals.
gosub100
I'm in a bad spot because I love swimming but I can barely hold my breath for 20s.
FollowingTheDao
Is it healthy to get into a near death experience just to get something done?
Why is it "bad" to be in a lethargic state?
Have you ever asked yourself these questions?
jboggan
I wouldn't characterize it as a near death experience but an activation of the mammalian dive reflex. It's a pretty profound physiological set of changes that most people have never experienced, oddly.
elric
What makes you say that breath holding for diving is a "near death experience"? It's pretty safe from what I can see?
samus
You don't get near death experiences just by holding breath, not even close. You might eventually be able to make yourself pass out though, so never ever practice long breath hold under circumstances where a loss of consciousness would be a danger, e.g., while driving, close or in water, close to streets or high drops or stairs, etc.
Lethargic states stop you from doing what you want to do and to manage your time effectively. Allocate time being in such states for resting or sleeping hours.
jkingsman
I've had this described to me as basically the combination of neuro+psychological effects of hyperventilation (respiratory alkalosis) in a peaceful/positive environment (as opposed to anxiety-attack-driven or etc.), plus the meditative effects of deep breathing, plus the meditative/brain-entrainment effects of rhythmic movement of a major central/core muscle (diaphragm). Together, those often cause euphoria, altered states of consciousness, and cognitive shifts not too far off from psychedelics.
Could someone who is more familiar with it affirm, adjust, or deny that as a general (medically-grounded/secular) summary of breathwork?
a1371
I have a degree in building science, so maybe I can chime in. Note of caution: you will find yourself breathing heavily after reading this. It's normal.
We do a terrible job at ventilating our indoor spaces. As a cave-dwelling species our brains are quite comfortable with tuning out bad smells and tolerating stale air -- but the effect of it on our mode and well-being is almost immediate. You don't notice the effect, but it is there.
That's why they tell you if the airplane's cabin depressurizes, put on your own mask first. People who don't manage to that quickly enough their eyes stay open, they don't even feel anything is wrong, but they are physically unable to put on their masks until they pass out.
If not eating proper food kills you in 3 weeks, not breathing proper air kills you in 3 minutes. Yet, people spend thousands of dollars on a new diet, but have no idea what kind of stuff are going into their lungs.
The situation is not life and death. It's feeling nice versus feeling low. People end up with indoor air that is often stale and full of volatile compounds. We often make it worse by using essential oil diffusers and not using the vent hood when cooking.
When you do a breathing exercise, all of a sudden you are giving your starving brain a dose of what it could be like. When you have a walk in the nature, you do the same.
So yes, breathing exercises are great, but it's even better if we fix our indoor environments to feel great at all times.
vwcx
The FAA puts on workshops around the country with a portable reduced oxygen training enclosure (PROTE). You sit in the enclosure (looks like a sealed vinyl tent), they reduce the available oxygen and simulate hypoxia. You've got a clipboard with some basic math problems, a maze to trace, etc. The trainers continually engage you for 3-4 minutes as you slowly get more hypoxic.
As a pilot, it was eye opening to see first-hand what happens to me when experiencing hypoxia. The trainers were talking to me, and I was replying, but was unable to tell them what 17 minus 4.5 was. My pulse oximeter was in the low 70s. Two sips of oxygen from a mask and I was right back to normal. I learned that my first symptom (the clue that something is really going wrong in the cockpit) is tunnel vision.
null
j_bum
Destin from Smarter Every Day (YouTube) has a wonderful video demonstrating this effect [0]. I’d recommend watching the whole thing, but you can see how much of an effect it has starting around the 6:00 mark.
pkaye
How do you measure indoor air quality? CO2 levels?
a1371
Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine, but in reality CO2 acts like the canary in the coal mine. When it climbs, it shows accumulation of stuff you don't want to deal with.
Measurement of compounds is best done using a monitor like Aranet, but incidental bumps in different values don't mean much. Long trends matter. If Radon is an issue in your region, a detector for that. Mold testing kits are readily available in market indicating moisture issues and you can get lead and other hazmat testing done diy/professionally
AlchemistCamp
Buy an air quality monitor. There are tons on Amazon. Here’s an example: https://www.amazon.com/dp/B0DZHJSQ7Z/
accrual
I'ver heard the Aranet4 is quite good for this but haven't yet been able to justify buying one. I do try to open windows frequently, though.
Havoc
Both particle measures and co2 sensors are somewhat affordable especially if buying raw sensors.
The up shot of it is ventilate frequently and dry heat cooking that browns anything (think steak in pan) releases a shit ton of particle so hood and open window
cptskippy
People seem fixated on measuring CO2 specifically and often purchase expensive sensors ($$+) or devices ($$$) to measure CO2 levels.
There are inexpensive sensors ($) that detect a variety of VOCs but cannot distinguish between them and CO2. They'll never give you exact concentrations but they are consistent, broad spectrum, and will alert you of change. IMO these are a better option.
colechristensen
Measure VOCs, PM2.5 particles, and CO2
Affric
Sounds like you’re just making the argument for moving to the wet tropics
maebert
Very much on point.
That said when facilitate breathwork sessions i trade the peaceful hippie music for edm (and it actually works better because it encourages people to stay with the rhythm and get into the same mildly trance-like state you might get into while exercising to repetitive music).
crummyglow
>Together, those often cause euphoria, altered states of consciousness, and cognitive shifts not too far off from psychedelics.
It must vary between people, because no matter the environment if I breath too eager, whether on purpose or accidentally (like working out) it just becomes really hard to think, everything starts to tingle and all my muscles lock up. A very not-fun time. Also dangerous with weights.
maebert
The tingles and muscle cramps (tetany) are a normal byproduct (basically your neurons on your smallest muscles and under your skin get more excitable due to a molecular rube goldber machine set off by lower CO2 balance in your blood). It's uncomfortable, but unless you are suffering from epilepsy not dangerous and there's no lasting effects.
I did a longer writeup on the physiological effects here if you're interested: https://docs.google.com/document/d/1RuDv_E9osM1CCFWZMywMru9J...
quantum_state
What you described is indeed true. There are breathing sessions at the Lifetime gym provide exactly the condition. People involved were amazed by the effect on their metal state.
shishironline
Your summary is exact. Medical personnel here
ValveFan6969
I'm a philosopher, not a medical professional. But I can tell you that philosophy and deep breathing are inextricably linked. Breathing deeply in of itself is a philosophical exercise, one that centers and grounds oneself in the here and now of the universe that surrounds you, and the universe that lies deep within you. It's a cosmic balance between the metaphysical and the empirical. As a philosopher, one must be able to breathe deeply, so one can breathe in, hold, and spew out the deepest and most esoteric pearls of knowledge unto the masses.
hashmap
Put on a five-minute song and start hyperventilating. You can tell pretty quick.
maebert
i am a (former) neuroscientist and breathwork facilitator (mostly conscious connected breath) — AMA.
the effect of decreased co2 concentration on vasoconstrictions (and also alkalosis-induced tetany, ie your muscles cramping, which happens a lot during breathwork) are well known [1], but i've never seen them quantified in such a clear way. It's cool to see mainstream science give it a closer look!
[1] for anyone interested, I wrote an explainer here: https://docs.google.com/document/d/1RuDv_E9osM1CCFWZMywMru9J...
elevaet
This is a bit off topic, but what do you think about people doing nitrous recreationally? It's always concerned me that people are inhaling close to pure nitrous oxide and holding it in. I've always wondered if this creates damaging low-oxygen conditions without the normal reflexes kicking in, and if this can cause brain/neuronal damage.
I believe in medical settings it's delivered in a mixture with O2, but in recreational settings it's usually inhaled directly.
I see a lot more talk about the risks of vitamin B12 depletion, and not much talk about O2 deprivation, so not sure if everyone else is crazy or if it's me who is the crazy one.
maebert
I'm not one to tell people not to have fun, but i also lost a friend to respiratory failure after prolonged nitrous abuse, and had more then one start having auditory hallucinations. I think it's waning in popularity compared to 10 years ago, but maybe I'm just out of touch with what the kids get high on these days
Youden
I was being treated with nitrous medically. I asked the anaesthesiologist about how it works recreationally and his answer was that yes, it was mostly just hypoxia.
soulofmischief
This is easily falsified by a cursory internet search about the physiological mechanism behind nitrous oxide's effects. It is appalling that a medical professional would so confidently give you an uneducated, crackpot answer. The exact same mechanism which knocks you out gives you euphoria at lower doses.
If someone holds their breath long enough to cause hypoxia when inhaling nitrous oxide, they have other problems. You can easily hold your breath 1-2 minutes while sitting on a couch without experiencing hypoxia. If you're experiencing euphoria as strong as what nitrous oxide causes from hypoxia, you're basically about to die.
klik99
This is why you shouldn't trust experts on stuff outside their speciality, this answer is just wrong.
You don't even need to research it, the lived experience of being in a dentist office with mixed oxygen and nitrous produces the recreational effects - if it was mostly hypoxia, having oxygen mixed in would have a greatly diminished "recreational" effect.
I mean, it is true most people doing it recreationally are giving themselves mild to severe hypoxia, but that doesn't mean the effect is caused by hypoxia
meindnoch
Bullshit. You aren't supposed to be hypoxic when using nitrous. You take a half-breath of air, and then breathe in the n2o.
s1artibartfast
As a Neuroscientist and breathwork facilitator, do you think there is any harm in intentional apnea (e.g. free diving, static holds, ect)?
At what point does cell damage (not necessarily death), kick in? As someone involved in these sports, I operate under the assumption that any damage would kick in after loss of consciousness. For example, if I hold my breath, even for 4 or 5 minutes but dont pass out, that is an indication I am still in the range of safe practice. Anecdotally, I know many people who have spent their lives doing breathholds, and they dont seem any worse for wear.
Are there any high quality studies that look at potential brain damage prior to loss of consciousness?
eigenschwarz
Does this help? I am a physicist with interest in these subjects and have always been wary of breathwork because of tetany and the following studies. What do experts closer to this field make of these?
[1] "Brain Damage in Commercial Breath-Hold Divers" https://journals.plos.org/plosone/article?id=10.1371/journal...
[2] "Do elite breath-hold divers suffer from mild short-term memory impairments?" https://cdnsciencepub.com/doi/10.1139/apnm-2017-0245
Ref. [2] is especially concerning to me in pushing in any sort of static apnea training or breathwork: "The time to complete the interference card test was positively correlated with maximal static apnea duration (r = 0.73, p < 0.05) and the number of years of breath-hold diving training (r = 0.79, p < 0.001)."
maebert
So the tetany in breathwork is generally caused by the decreased CO2 concentration causing respiratory alkalosis (ie blood gets more alkaline and has a ph balance of > 7.5), which in turn causes the protein albumin to bind more strongly to calcium and not release it as it's supposed to, and calcium is an important regulator in voltage gated ion channels in neurons.
Long story short, your neurons get just a tad bit more excitable because calcium that usually acts like the bouncer to the hot club is busy snogging albumin. That has very little effect in places in the body, but in motor neurons that control your smallest muscles (face and hand), and in sensory neurons under your skin it does move the needle — that causes the muscles to contract and your skin to feel tingly, both exactly the same cause.
This is the reason people with epilepsy should _NOT_ do breathwork, but for otherwise healthy adults there are no negative long term effects of respiratory alkalosis — a few normal breaths to balance out your co2 and the symptoms will go away.
sentimentscan
Could you please explain more about the Ref[2], what does it mean beyond what is in article and how serious is it? "These findings suggest that breath-hold diving training over several years may cause mild, but persistent, short-term memory impairments"
Can you tell more about recreational nitrous oxide and when does the "damage occur"? Is there the same thing with wim hof? (like for example with oximeter 80 Sp02 or below?) I got in wimhof/oxide around 80 Sp02 the interesting thing is I got this feeling with fighting to hold my breath but below 90 I kinda needed to convince myself that I should breath in both cases,
kragen
Thank you, this is terrific! Why should tetany be worrisome?
Edited to add: the second article seems to be about decompression injuries, rather than apnea-induced brain damage?
latchkey
This feels like one of those cases where science is catching up with something that's been done for a long time already.
aeblyve
Worth noting that a decrease in end-tidal CO2 pressure (i.e., decreased amount of Co2 in an exhalation) is not in itself a statement about the amount of Co2 in tissues. A rudimentary analysis might even say that lower Co2 as measured in exhalation implies that more Co2 is retained in the tissues.
Bohr effect and others corroborate the idea that Co2 is not just a "waste gas" produced by respiration but has an important biological role in its own right.
Ingestion of baking soda, which supplies Co2 to tissues, is so effective at countering the effects of lactic acid from muscle overexertion that its administration is banned in horse racing.
It stands to reason that higher Co2 can protect against lactate throughout tissues, perhaps even including the brain, especially in a condition where the brain favors fermentation over respiration (as in cancer, per Warburg effect, and depending on who you ask, in mental illness/depression)
bentt
I got into doing this Wim Hof breathing exercise a few years ago and it was definitely intense. Unsure if this is related but sounds similar.
onemoresoop
Intense but did you get any lasting change from it? Are you still practicing? I did some breathwork and disturbed something with my natural breathing pattern. For about two weeks I had insomnias and was constantly lightheaded. Im reluctant to try again..
prox
I used to teach various pranayama’s (yogic breathwork) and we tend to go easy, especially if you are not going to go into a 3 year seclusion as a lifetime yogi.
All practices were 3 breaths only. If you really enjoyed one or the other, you can do them a few times a day.
Because exactly as you say, you don’t want to disturb the natural pattern. If you have an unhealthy breathing pattern, the idea is that yoga, rest and relaxation will take care of the rest.
Beyond that we are not doctors, so if I noticed something peculiar with someone’s breathing, or it came up, I would direct them to a professional.
I never liked the Hof method, it works on the wrong side of the nervous system for me, as it’s too activated. I feel it’s good perhaps if you got to do something stressful and you need resilience.
bentt
Yeah the Wim Hof breathing feels more like a challenge or test that you come down from than a relaxing thing. Consistent with his "jump in ice water" thing.
bentt
I did it when I was really working on myself emotionally and it was for a limited time. It could be a bit scary because of the extreme feeling of lightheadedness. But it did cause a pseudo euphoric feeling too. Afterward I felt invigorated.
But yeah it had a layer of unpleasantness that made me not continue long term.
maroonblazer
What kind of breathwork did you do?
onemoresoop
Circular but without outside supervision. Not sure if I did something wrong or if I need some customized practice. I am often running out of breath/out of sync breathwise when singing, often getting lightheaded effect which I do not like at all.
reverendsteveii
In the occult community altered states of consciousness are something we regularly pursue in order to affect consciousness on an ongoing basis after a return to baseline. The sort of breathwork talked about in this article (tummo/bellows breath) are big parts of a lot of people's practices, myself included. We also do physical ordeals, flow states, and psychoactive drugs in efforts to take manual control of our perceptions of things. Personally, I meditate for about 20 minutes, then lift heavy weights or do medium-distance high intensity cardio (20-30 minutes of going as hard as I can) then smoke marijuana, then play hand drums and hyperventilate in an effort to induce a ritual mindset, then use mantras and sigils to try to create a mindset that's more conducive to my goals. I can't say empirically that it works, of course, but anecdotally before I started doing this I was a 30 year old obese, hopeless college drop-out pillhead living in my childhood bedroom and now I'm a 40 year old married homeowner full stack engineer with 10 years off pills who can benchpress his dad and I've learned to play the banjo and the drums in the mean time. All of those good things I've listed came to me through tons of mundane effort, smart decisions and good luck but also at least correlated with me using the ritual structure I outlined above to choose them as goals to focus on and rewrite myself into the kind of person who picks goals, focuses on them and completes them.
anshumankmr
I rarely practised breathwork in my life but during my final year of high school I was basically locked in my house, and got a vitamin D deficiencey (quelle surprise) so I took up doing breathing meditation in a public park, and that really worked for me in a highly stressful period of time in my life, which got me some very good results, aced my exams, got into a decent college. I don't think I have applied myself as dedicated to anything as intensely as I did. I regret not making it a daily habit in my life, unlike gymming. Although I still sort of deep exhalations in highly stressful situations but thats about it. Also if you count breathing in and out during heavy lifts, that helps a lot too in my form, especially during squats.
layman51
What kind of breathwork? Is it kind of the same as box breathing? That’s breathing in for four seconds, holding it in for four, exhaling and pausing all for four seconds.
pedalpete
I've experimented with holotropic breathwork, and was quite amazed at the experience. Unfortunately, as much as I've tried to re-create the experience while not lead, I find my mind just doesn't want to go beyond about 5-10 minutes of breathing, vs the 30 minutes I did in breathwork sessions.
Having said that, I think the design of this study could be much improved. It shouldn't be too difficult to create a double blind group environment using headphones (think like a silent disco) where both participants and researchers don't know who is listening to guided or not.
I'm also not sure if the biomarkers are the best. DMT can apparently be detected in saliva, and I believe the theory is that during holotropic breathwork, the pineal gland releases more DMT than normal.
rqtwteye
" find my mind just doesn't want to go beyond about 5-10 minutes of breathing, vs the 30 minutes I did in breathwork sessions."
Same for me. I did a workshop with Wim Hof and the breathing exercises were great with really profound effects. But I couldn't make myself practicing at home with the same intensity regularly. I also developed a pretty bad cough after a few weeks. Probably from the dry air where I live.
maebert
it's an incredibly hard workout, depending on the style you're actually using a lot of muscles that you don't typically exercise, so your body wants to naturally give up after a while. it took me probably 6-8 sessions until I could reliably do one myself.
replete
I wonder if there's a vagal nerve effect from the increased chest pressure while holding your breath in.
I do the 'double sharp inhale' method for the anxiolytic effect occasionally - not really something you can do at the office however.
groos
I hate getting startled, even when I realize right away that there is nothing to worry about. But the physiological effects, once set in motion, carry on. My heart seems to skip a beat and then rev up to a high rate and it's uncomfortable, taking some time to come back down to normal.
Some years ago, I discovered a technique to suppress the effect of being startled. I just breathe in sharply, using mostly my diagphragm, before my heartrate goes up and it keeps things normal as usual. I wonder if this is also using the vagus nerve to suppress being startled?
ordu
> I wonder if this is also using the vagus nerve to suppress being startled?
I don't know about vagus nerve, but I can propose a different explanation. Emotions can change the state of your body, your brain feels the state and triggers emotions. It can become a self-reinforcing loop. In particular, diaphragm contractions or tension can be such a state. For example, I have sometimes issues with getting rid of anxiety, and when it happens, it is because of my diaphragm. It becomes tensed, I feel it and so I feel anxious. To get rid of anxiety I need to a) rationalize it away and b) keep my diaphragm relaxed.
When you overload your diaphragm with some irrelevant activity you may be breaking the self-reinforcing loop. Or maybe this movements of your diaphragm trigger some other response that wins. As a wild guess, your organism expect that after a deep breath you'll hold your breath for some time, and so it limits the heart-rate to not burn oxygen too fast.
enaaem
This is btw the whole idea behind Vipassana. The idea is that most of your suffering comes from your unconscious reaction to bodily sensations and you can train yourself to become more aware and equanimous.
djmips
That sounds like an excellent theory.
lr4444lr
I don't understand: shouldn't hypocapnia or respiratory alkalosis in all forms lead to reports of altered states of consciousness if decreased CO2 saturation is believed to be the cause of this breathwork's effect?
yosito
I'm not sure about other forms of respiratory alkalosis, but I do know that it's quite common for people to claim that breath work leads to altered states of consciousness.
As a surfer, I've done a few breathwork classes even though I've never been close to being in conditions that really needed it. There is a tremendous amount of training that you can do to basically change your conscious thoughts in an instant. Going from 180bpm heart rate and anxious panic to a static breath hold for up to a minute while being ragdolled and disoriented, is basically ego death. If you watch some gnarly big wave surfers talk about breathwork, they talk about rapidly flushing out your air in 3-4 big breaths, calming your heart rate, and even laughing, all right before or in anticipation of a pounding. Plus the whole Gerry Lopez yoga and meditation era of the 70s made it clear how important breathing and mental state were.
In any case, this is something every single surfer beyond a certain level is required to master, so I'd love to see data from that kind of cohort. The old lady freedivers of Jeju Island would be cool too.