Intermittent hypoxia increases blood flow and benefits executive function
52 points
1 day ago
| 27 comments
| onlinelibrary.wiley.com
| HN
AceyMan
13 hours ago
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You mean, forcing your body into a situation where it needs more oxygen than is available is ... good for you? That sure sounds like cardio-aerobic exercise, doesn't it?
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evanjrowley
4 hours ago
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Yes!

Not to be confused with professional work where the only feasible way to complete the job is to spend hours wearing respirators clogged with particulate, having only one free hand to move heavy/bulky equipment through tight spaces, where getting a full breath of air is anatomically impossible. Extended periods of hypoxia are taxing on the body and require periods of recovery.

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foxyv
1 hour ago
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Generally, you don't get hypoxic while using a clogged respirator. The problem in such cases is mild hypercapnia and increased work of breathing (Respiratory loading). Hypercapnia in general can cause short term cognitive issues but not long lasting issues. Respiratory loading can cause temporary pulmonary edema.

However, the respiratory loading and hypercapnia are extremely mild in the case of clogged respirators. Especially when compared to divers and snorkelers. The usual problem is that the respirator stops preventing contaminated air from reaching your lungs. As the filters become clogged, the air bypasses the seal around your face.

This is why I prefer a powered respirator. Zero work of breathing and positive pressure at the seals.

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evanjrowley
22 hours ago
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But depending on how it's done, may possibly damage your vision: https://www.sciencedirect.com/science/article/pii/S245199361...
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foxyv
1 hour ago
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Erotic asphyxiation is way different from intermittent hypoxia. Typically erotic asphyxiation is cutting off the flow of blood to the brain by constricting the veins and/or arteries in the neck. Intermittent hypoxia in the case of divers and Wim Hof enthusiasts is a breath hold. This doesn't cause a spike or decrease of blood pressure in the brain.

> Intermittent hypoxia (IH) entails alternating between intervals (typically 2–6 min in duration) of breathing normoxic (i.e., room air) and hypoxic (i.e., FiO2 of 10%–13%) gas mixtures and is a protocol that increases CBF and has been identified as a potential intervention to improve brain health (Panza et al. 2023). The onset of a hypoxia interval elicits an acute response wherein a rapid chemoreceptor-identified reduction in arterial (SaO2) and cerebral tissue (ScO2) O2 saturation stimulates increased ventilation and heart rate (HR) to maintain homeostatic O2 delivery

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joecool1029
22 hours ago
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I am wondering if this related to hypoxia inducible factor (HIF) activation.

Seem to recall the nootropic Noopept allegedly acts as an activator for HIF-1. Maybe there are others. Could possibly be a therapeutic target, maybe not. This is not my area of study, I'm just reiterating some of what I've read in the past.

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etrautmann
20 hours ago
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The main effect of a reaction time reduction looks incredibly small and is all the way in Fig 6. I would not over interpret this result without higher N and some discussion of effect size.
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tapoxi
22 hours ago
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Finally, an upside to sleep apnea
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samus
22 hours ago
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There is overall no health benefit since the hypoxic phase is quite long and creates stress during a time when the body is supposed to rest and recover. And that compounds with the underlying issue, usually mouth breathing, bad pillow, bad sleeping position, or a combination of these.
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elric
19 hours ago
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Pretty sure that was meant as a joke.

Mouth breathing is not a cause of sleep apnea, but it can be a consequence. Bad pillows and bad sleeping positions aren't causes of sleep apnea either, but some people do have "positional sleep apnea" where the apnea is (usually) much worse on the back and much better on the side.

One can also have sleep apnea without ever experiencing hypoxia. Drops in oxygen saturation during hypopneas are very minimal, and pretty much nonexistent with respiratory effort related arousals (RERAs). Not breathing is bad, but for many people with sleep apnea, the problem is the constant arousals and the lack of decent sleep, not a lack of oxygen.

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ang_cire
21 hours ago
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Came to say this. If one day I don't wake up, at least everyone will know my brain was lit beforehand!
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evanjrowley
22 hours ago
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Maybe this is the link between sleep apnea and hypertension.
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hackingonempty
21 hours ago
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> Healthy young adults (N = 24)
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glerk
10 hours ago
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It intuitively makes sense that moderate exposure to a variety of stressors (resistance training, fasting, cold showers, sauna, sleep deprivation, etc.) forces your body to overcompensate, develop adaptations, and become more resilient.
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1970-01-01
22 hours ago
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Makes me wonder if professional divers are statistically more intelligent than average, as they will experience hypoxia as part of the job.

https://en.wikipedia.org/wiki/Professional_diving

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ceejayoz
22 hours ago
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They shouldn't experience hypoxia. That's what the air supply is for.
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1970-01-01
22 hours ago
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ceejayoz
21 hours ago
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Barring really traditional (and now very rare) pearl/scallop divers, professional divers aren't doing it by holding their breath.
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PaulHoule
21 hours ago
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I never got "deep" into it but everybody told me that breath holding diving can be really dangerous.

I know part of the SCUBA story is that phenomena like nitrogen narcosis are particularly dangerous because you need your cognitive capacity to survive in the underwater environment.

In the surface world I can go to a party and drink eight beers and maybe throw up and act like a dumbass and embarrass myself and then wake up with a headache the next morning. That level of incapacitation under water would likely be fatal.

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nradov
20 hours ago
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Nitrogen narcosis isn't usually a significant factor in breath hold freediving. They do feel it on extremely deep dives but most aren't going past about 100 ft / 30 m where it becomes really noticeable.

https://alchemy.gr/post/429/dealing-with-narcosis-when-freed...

Technically it's not just nitrogen. Most breathable gasses other than helium have some narcotic potential. This includes oxygen, although the magnitude is unclear. Elevated CO2 levels (hypercapnia) can also seriously reduce your cognitive capacity via multiple mechanisms.

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foxyv
57 minutes ago
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At very high pressures, helium is actually the opposite of a narcotic. This is why it is introduced in Trimix for deep dives. It kind of offsets the narcotic effect of the high pressure oxygen. However it can also cause trembling if there is too much of it.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7478267/

To offset this problem, world record divers are introducing Hydrogen to their mixtures at extreme depths.

https://en.wikipedia.org/wiki/Hydrox_(breathing_gas)

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PaulHoule
2 hours ago
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It's not so much about nitrogen and narcosis from other gases, it's that underwater is a dangerous environment where you can get in trouble quickly if anything goes wrong.
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ceejayoz
21 hours ago
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Yeah, when I learned scuba, I was told the rule with freediving is your buddy stays on the surface while you dive; that way they can rescue you if you can pass out.
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Hnrobert42
20 hours ago
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While ascending, the air in your lung expands. If it can't go out your mouth/nose, then it expands your lungs or is forced through membranes. Either way, the results are not good.

Nitrogen narcosis is another risk of SCUBA diving, but it is not really related to breath holding.

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nradov
18 hours ago
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Lung over expansion issues can only happen when ascending after breathing compressed gas under pressure. That isn't a problem with breath hold freediving.
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captainbland
5 hours ago
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It probably wouldn't be significant as executive function and overall intelligence can change independently.
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catigula
21 hours ago
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Professionals at anything, let alone an elite performance sport like this, are almost certainly statistically more intelligent than average.
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dinkblam
21 hours ago
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Can you link to a study backing this up?

I'd say most professional athletes are less intelligent than average…

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untrust
20 hours ago
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I think that this way of thinking is a little reductive. Every sport depends on certain intelligence metrics, and the brain is ultimately the operator behind all movement. The intelligence required to read a defense and solve a complex math problem may be different, but being good at either require intelligence.

A professional athlete in team based sports, at any given moment, is parsing a ton of data and responsing with quick reflexes and intuition to their changing environment. For example, quarterbacks in the NFL are reading a defense, parsing coverage, and making split second decisions after the play begins to develop.

A soccer goalkeeper is ensuring precise geometry to stay in an optimal position to make a stop, ensuring they are creating a triangle between the ball and the goalposts to optimize their position relative to the possible shooter.

Ontop of all of the in-game aspects, there is intelligence required to train to optimal levels, and hand waving this away as the coaches responsibility is not based in reality. Professional athletes have to stay very mentally focused in their training off the field to achieve their on the field results.

A lot of people judge professional athletes intelligence based on their communications with reporters and on field interviews, but public speaking ability and intelligence are not necessarily correlated. Your smartest engineer is probably not great at making keynote speeches, and likewise would be particularly terrible if they were making them after exerting extreme effort (like athletes do in post game interviews) or while they are pumped with adrenaline with an elevated heart rate (conditions sideline interviews tend to take place in).

All of this is to say, professional athletes arent all meat heads like most computer programmers and bookworms tend to believe. Your judgement that they aren't smart is probably based off of your bias and you are likely overweighting your analysis on a few notable dumb athletes against the crop.

Also, to top it all off, every sport is different, so you can't lump professional athletes into a single bucket.

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nradov
20 hours ago
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Why would you say that? Personally I would say that those who make unwarranted assumptions and post them online are less intelligent than average.
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paulcole
15 hours ago
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What is the difference between what they said and this that they responded to?

> Professionals at anything, let alone an elite performance sport like this, are almost certainly statistically more intelligent than average.

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ed
21 hours ago
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s/professional divers/free-divers/
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m463
13 hours ago
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I know people that live at altitude control their weight better.

I also know top athletes train in hyperbaric chambers (extra oxygen).

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LorenPechtel
1 hour ago
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I'm not remotely at that level but I can see the difference between my performance in local terrain vs Death Valley. There's a decent amount of stuff down there bumpy enough to be interesting but not so bumpy as to make it hard to get through. But, on the flip side, I have never been able to find a good, sustainable pace in the mountains.
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estimator7292
19 hours ago
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Intermittent fasting, but for oxygen. Breatharians will be elated
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emmelaich
21 hours ago
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I was given a tip to stay awake a while back: hold your breath for a little while. Apparently this well known for many years but I had never heard of it.

Seems to work, but this was in the context of driving which I do not recommend, having fallen asleep at the wheel once and woken up rally driving down some paddock.

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jrootabega
22 hours ago
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I'm not knowledgeable enough to confidently verify this from the linked material, but aren't they keeping CO2 levels the same during the hypoxic periods? i.e. isn't this significantly different than just holding your breath/being choked/sleep apnea?
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deadfece
22 hours ago
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Seems like that was what they set out to prove.

Hopefully some of that can be reproduced in further studies.

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amriksohata
5 hours ago
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Nisshesha Rechaka and Kapalvati prescribe very similar processes to create a similar (but different) state of hypoxia, i.e yoga
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ThrowawayTestr
22 hours ago
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So those breath holding contests we had at school were making us smarter?
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eastbound
22 hours ago
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In aggregate yes. When the most stupid die, the average IQ increases.

I’m joking, by the way. The more risk-taking people might be the ones who push civilization forward. Starting with Churchill…

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everythingfine9
19 hours ago
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So my mild sleep apnea is a good thing, got it
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PaulHoule
22 hours ago
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... note that the article linked from this discussion https://news.ycombinator.com/item?id=46168057 mentions intermittent hypoxia as a rapid acting treatment for depression right up there with Ketamine and ECT
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nradov
20 hours ago
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I guess it worked for Deadpool.
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wslh
21 hours ago
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A few days ago I linked some research to well known intervals running practice that include hypoxia: https://news.ycombinator.com/item?id=46169398
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ajuc
22 hours ago
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Asthma counts?
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Madmallard
16 hours ago
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Sounds not very believable and probably sampling bias and other hacked research parameters.
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LorenPechtel
1 hour ago
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Except I've seen this suggested elsewhere, beneficial effects from both skydiving and from scuba diving. Things that cause big swings in available oxygen.
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kylehotchkiss
21 hours ago
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don't tell the microdosers
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lubujackson
21 hours ago
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Is this the new Adderall?

...I'm not holding my breath.

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Hnrobert42
20 hours ago
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I'd love to see them develop an at-home protocol for this, but I'm not holding my breath.
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alex1138
20 hours ago
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brb
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elif
22 hours ago
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Another confirmation for wim hof breathing
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samus
21 hours ago
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Rather of its opposite (but similar): Buteyko breathing, which puts emphasis on building up CO2 tolerance and adopting more gentle, relaxed breathing patterns by inducing carefully controlled hypoxia. But I have to admit, I know only very superficially what the Wim Hof method is.
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ratelimitsteve
21 hours ago
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according to wimhofmethod.com their breathing exercises are meant to increase oxygen levels, not decrease them
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elif
4 hours ago
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Wim hof breathing is both hyper and hypo.

You hold your breath and then breath intensely in an alternating pattern

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elif
1 hour ago
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At the end your blood is very oxygen rich. It is incredible
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bitwize
14 hours ago
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Autoerotic asphyxiation bros be like "hell yes, we ARE the master race"
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