Dive reflex not always helpful?

[naiad]

I don't think there is enough awareness about this issue in diving and other watersports. I can't remember it being mentioned as a safety issue anywhere. I'm sure many accidents must be caused by it, particularly in scuba. A mask flooding, drysuit leaking or falling into water can cause a disastrous situation.

Although I hate cold water with a passion, I have a reasonable amount of self-control because of my apnea training, so I am probably less likely to inhale water than someone with no training. Despite that, I know that if my mask flooded in cold water on scuba, the best I would be able to do is make an emergency ascent. I would not be able to clear the mask, or even to breathe normally.

Another issue is that what counts as 'cold' water varies considerably from one person to another. Some people say that 18c is warm, when for me it is unbearable. Others will complain that they start shivering in 30c water, which for me is warm even if I stay for hours in a swimsuit.

 

[atomichaggis]

I don't think its a huge issue In diving and other watersports as You take precautions against the cold and you anticipate the shock. Wearing the the requisite thermal protection is just basic stuff and On Scuba at least You got something to breath until Your body adapts in the case of some suit malfunction. Most people who are caught out by the extreme cold are neither adequately dressed for it nor do they anticipate it... or in My case I just overestimated My own tolerance of really cold water, that is really a personal thing. It doesn't seem to bother Mr. Fattah or Fondueset who is good down to 3C when He is not levitating above lotus flowers on a carp filled lake or whatever.

 

[naiad]

I wasn't thinking about experienced divers, more about new divers who may have qualified abroad somewhere nice and warm, and are not aware of the risk.

Anyone who is diving in 3C water is superhuman. :king

 

[atomichaggis]

I was reading some of Mr. Fattahs posts about diving in BC with no suit and the time He spent in the water is incredible. It is said You got around 15 minutes in the water here before you are gone... Maybe science knows nothing and you just gotta get used to it.

 

[turtle]

atomichaggis - what's with all the capitals on your pronouns? His, Hers, Mine... sorry, It's just bugging Me.

f

 

[atomichaggis]

LOL... now that is observant. first the Sam Still gag now this. It is just a bad habit like... that.
I never felt that the owner of the first person pronoun should be more important than the second or third person so they got a capital and all of Their posessive pronouns as well... i guess it falls under the 'Important words' rule.
I might be a little abrasive at times but I find having more capitals than others a bit arrogant. Don't let it bug you too much.
Lousy grammar and reasoning is to be expected from someone who never finished school.

 

[wet]

Lucia, are you a regular member of an ochestra, playing a brass instrument or woodwinds, where air pressure is required to produce sounds? If so, it possibly might conflict with breath holding, not the length of time, but rather the effects of air pressure on the larynx, pharynx, epiglottis, etc. (Is your packing similar to a wind instrument pressure? When you breathe up, do you pressurize the throat, or keep it about the same as outside air pressure?)

2% of humans develop a laryngocoel (sp), most often related to wind instruments or balloon inflating or similar activities. (from Tecumseh Fitch, Speech and Language, IIRC) This is a little air sac in the larynx that inflates when pressured, it was greatly enlarged in our hominoid ancestors, but reduced to a vestige like the appendix in humans.

 

[wet]

Then that is an important safety consideration for diving and other watersports.

What a useless reflex, I don't know how it could possibly be good in any situation to gasp when falling into cold water.

Feet first: gasp, wading in cool water
Face first: MDR, diving in cool water

It's actually the same reflex, maximizing oxygen retention, but face-first shuts off the inhalation phase, while feet-first exaggerates the inhalation phase.

Your best MDR response might be this approach:
(with a buddy at poolside watching and estimating time, not a small crowded pool)

1) NO wetsuit, just swim suit, warm and dry, no nose/ear plugs/mask/cap.
2) PLAN only ONE dive, (afterwards hit the hot shower, then dry and leave).
3) NO breathe up, just walk to the edge of deep end, casually deflate lungs while leaning forward, and pushing gently off into the water, entering face-first with arms down at your sides, to between 1/2 to 2 meters deep, glide down and forward until stopping, then casually but with strength, kick a few times while gliding hydrodynamically, then, when ready to climb, [*see note below] bring your arms forwards and SLOWLY power stroke laterally at sides (no more kicking) diagonally or vertically up to the surface, turn onto your back and inhale a few slow moderate breaths (not deeply) while laying flat like a board on the surface relaxing, backstoke over to the edge and climb up and leave pool. You did it. Shower, dry, go home, forget it.
4) It's not the length of time or distance, it's the technique, 20 seconds submersed is fine. 1' MDR > 2' HV.
5) That night, dream the dive again, let the experience come back, learn from it subconsciously while sleeping, adjust little things (slower or faster kick, hear echoes under water, sense difference between surface temp. and depth temp. etc.).
6) Repeat pool dives often, after the first day, 2nd and 3rd dives are ok, but stay focussed on technique, hydrodynamics and sensing conditions. No more dry/wet statics until normal dives are smooth enough to make a dolphin smile.

* Assuming no intruders and not close to wall, close eyes during ascent and allow face skin to inform you of your position. Your ears know the depth and body orientation via the eardrums and the 3 semicircular canals of the inner ear, your hair/forehead/eyebrows/eyelids/eyelashes know the speed and the difference between water and air temperature and pressure, rely on this sensitivity. Once in backfloating position and ready to scull to the edge, only then open the eyes and go.

(If what I say doesn't make sense, don't do it. Only under supervision in optimum conditions.)
DDeden

 

[naiad]

Lucia, are you a regular member of an ochestra, playing a brass instrument or woodwinds, where air pressure is required to produce sounds?

No, never played a brass or woodwind instrument, except a few recorder lessons when I was a kid. rofl

Maybe I will try the one-dive approach, with a buddy. I am still a bit scared of getting into cold water, because for me the gasp reflex happens even if I put my face only in the water. It is not so bad if I take a deep breath and hold it, and much worse with empty lungs.

 

[wet]

No, never played a brass or woodwind instrument, except a few recorder lessons when I was a kid. rofl

Maybe I will try the one-dive approach, with a buddy. I am still a bit scared of getting into cold water, because for me the gasp reflex happens even if I put my face only in the water. It is not so bad if I take a deep breath and hold it, and much worse with empty lungs.

I played trumpet a couple years, but not enough to cause laryngocoel. I think it only happens to people with unusually thin or weak larynx tissue or something.

I fully empathise with the dislike of cold water immersion. The reason I mentioned it was because I assume your available pools aren't really warm and the pumps keep moving the water around. The ideal would be very very warm at the surface (6" 15cm) and quite cool just above the pool floor, with the water almost still and thermally stratified, like in a sunlit tropical lagoon completely surrounded by reefs.

By breathing up, and then filling the lungs with air, the body's sensors read "low CO2 so plentiful O2", and keep burning O2 at a regular non-MDR pace.
Then when the CO2 rises due to the fast O2 burning, contractions or air hunger starts.

OTOH, having the MDR/gasp occur right away with empty lungs forces O2 conservation, burns O2 slowly and builds CO2 slowly. This registers in your mind as discomfort because you haven't gradually habituated to it. The same physiological gasp that tries to suck in air to the lungs is actually pumping O2 from the extremities. By sealing the mouth and nose (with tongue in back), the coldwater gasp has nowhere to come from but the blood cells and muscle cells rich in O2 in the limbs, biochemically kicking them to move faster towards the core to ease the pH differential.
DDeden

 

[naiad]

OTOH, having the MDR/gasp occur right away with empty lungs forces O2 conservation, burns O2 slowly and builds CO2 slowly. This registers in your mind as discomfort because you haven't gradually habituated to it. The same physiological gasp that tries to suck in air to the lungs is actually pumping O2 from the extremities. By sealing the mouth and nose (with tongue in back), the coldwater gasp has nowhere to come from but the blood cells and muscle cells rich in O2 in the limbs, biochemically kicking them to move faster towards the core to ease the pH differential.

Interesting. That makes sense. I remember that when I was a kid, if I was outside and there was a cold wind blowing, I would get an uncontrollable apnea reflex, which was unpleasant but bearable. It must have lasted for a few seconds. It still happens occasionally, but much less. It was very similar to the feeling I now get when I put my face in cold water.

 

[trux]

2% of humans develop a laryngocoel (sp), most often related to wind instruments or balloon inflating or similar activities. (from Tecumseh Fitch, Speech and Language, IIRC) This is a little air sac in the larynx that inflates when pressured, it was greatly enlarged in our hominoid ancestors, but reduced to a vestige like the appendix in humans.

Quite interesting, David! Can you tell us more about the laryngocoel? Do you know what did the big laryngocoel serve for at our ancestors? How does it collide with freediving? Wouldn't it be rather helpful - for example as an additional store of air for the ear equalization? Personally, when younger, I played quite a bit on diverse wind instruments (recorders, traverse flute, clarinet, saxophone), but never felt that it collided with my diving. Quite the opposite - it helped me greatly to use my breathing efficiently. However, I believe that the laryngocoel you mention is more of a problem at brass instruments like trumpet where a rather high air pressure is needed. Still, I bet that a trumpet player like Dizzy Gillespie could go easily 300m deep with a single mouthfill:

​

 

[wet]

Interesting. That makes sense. I remember that when I was a kid, if I was outside and there was a cold wind blowing, I would get an uncontrollable apnea reflex, which was unpleasant but bearable. It must have lasted for a few seconds. It still happens occasionally, but much less. It was very similar to the feeling I now get when I put my face in cold water.

Right, the fast combined thermal and pressure change on the face, and also in the throat triggers the reflex.

When you hold your breath with full-lungs, I think you are getting about 1/2 of this effect due to air pressure on baroreceptors in the mouth/nose/throat/lungs.

When you did empty-lung breath hold, that 1/2 effect was missing, so you only felt the struggle phase, without the benefit of the 1/2 effect.

What I've been saying, is that by first being warm and dry, and knowing that soon you will again be very warm in the shower afterwards, then, casually diving in slightly cool water, that if you relax and accept the "switch-over" discomfort, knowing that it's just a temporary adjustment your body makes as it "becomes one with water" (no longer bothering to carry this huge "bubble" of excess air in the lungs down under the surface), and let your body feel the water as you glide through, and limbs smoothly power you along, and then rising up again to the surface, you are fully aware and sensitive to your immediate environment, and gracefully exchange the gift of air. Upon contacting the surface, you will want to exhale, but don't push it out, just exchange it gratefully.

As you climb out of the pool, your body which was adapted to the cool water during the dive, is now warming up due to the aerobic metabolism required to deal with moving in regular terrestrial gravity, so do a brief stretch of arms and legs and trunk, and a moderate aerobic breathe-up (no forced inhale, just a yawn), this should give a blush or flushed face and a tiny sweat reaction (the opposing reflex of the gasp), and then go take a warm shower and dry off.

Actually, I think that both of these reflexes release biochemicals into the bloodstream including micro-doses of endorphins and natural steroids, that help relax during stress.

Anyway, like I said, if something doesn't sound or feel right, don't do it, take time to figure out what's happening. Don't rush a dive, relax a dive. Those super-fast dolphin's ancestors 50 million years ago were once very slow divers too, as were our ancestors at the seashores 1 million years ago. It takes time. Dive with dolphins, backfloat with sea otters, blow bubbles with koi, breathe.
DDeden

 

[wet]

Quite interesting, David! Can you tell us more about the laryngocoel? Do you know what did the big laryngocoel serve for at our ancestors? How does it collide with freediving? Wouldn't it be rather helpful - for example as an additional store of air for the ear equalization? Personally, when younger, I played quite a bit on diverse wind instruments (recorders, traverse flute, clarinet, saxophone), but never felt that it collided with my diving. Quite the opposite - it helped me greatly to use my breathing efficiently. However, I believe that the laryngocoel you mention is more of a problem at brass instruments like trumpet where a rather high air pressure is needed. Still, I bet that a trumpet player like Dizzy Gillespie could go easily 300m deep with a single mouthfill:

View attachment 15632​

Thanks Ivo! For you and other DB members, I added some further info.

Correct spelling is laryngocoele. It is a laryngeal ventricular saccule, or, overextended air sac in humans, sometimes found in trumpet players and traditional glass blowers, but seen in other people as well, sometimes congenital. The article below shows a trumpet player doing a valsava manuever with resulting "balloon" air sacs visible in the neck xray. He changed his method, and the problem was resolved. As you can see, it's in the neck, not the cheeks as in Dizzy. Our mammalian primate relatives, especially the anthropoids, and most obvious in the hominoids like the siamangs (see photo below of dueting siamangs above open water, with inflated air sacs) and orangutans, have much larger versions than humans ever have. A large male orangutan can hold 6 liters of air in the laryngeal air sacs (not including air in the lungs or trachea). [A large walrus can hold up to 50 liters of air in a different pouch called the pharyngeal air sacs, which it can inflate and then sleep in water with head above surface].

The laryngeal air sacs in Hominoids were most likely selected for head-up vertical flotation combined with bipedal wading (and resulted in the complete loss of the tail), but long preceded the uniquely human regular diving/backfloating phase, and by then were vestiges as they are today, except as I noted in 2% of the population. I would not recommend attempting to use them for air storage at depth, due to internal fluids entering the sacs when upside down and not being able to exit, potentially causing infections. I'd think that prolonged yelling and loud vocals might predispose one to laryngocoeles as well, but haven't read anything on it.

Let me repeat, AFAIK, laryngocoeles are not good for free diving, but at least hypothetically could be used as head-up float support (as they once likely were) like a life jacket, except their size has reduced very much compared to body size.

DDeden

Article: 2 page [PDF]
What a blow!
http://bjr.birjournals.org/cgi/reprint/71/847/799.pdf

 

[trux]

Thanks, David, for the details. Yes, I understood that laryngocoele is in larynx and not the cheeks. I just posted the photo of Dizzy to show a case of extreme mutation at a trumpet player due to the air pressure. If Dizzy, with such cheeks did not have also an extreme laryngocoele, than I do not know who could have it. I also posted it to show what I believe - that such malformation (regardless if just laryngocoele or also such cheeks) might be actually helpful for freediving, better told for the equalizing. It is still not clear to me why you wrote that it might conflict with breath holding, and why you think it could suppress the dive reflex.

 

[wet]

Thanks, David, for the details. Yes, I understood that laryngocoele is in larynx and not the cheeks. I just posted the photo of Dizzy to show a case of extreme mutation at a trumpet player due to the air pressure. If Dizzy, with such cheeks did not have also an extreme laryngocoele, than I do not know who could have it. I also posted it to show what I believe - that such malformation (regardless if just laryngocoele or also such cheeks) might be actually helpful for freediving, better told for the equalizing. It is still not clear to me why you wrote that it might conflict with breath holding, and why you think it could suppress the dive reflex.

Ivo,

I don't know where all the baroreceptors are in the tissues of the oral and nasal cavities, nor exactly what triggers which reactions. I associate inflated air sacs with floating, not sinking/diving/breath holding. I don't know if it suppresses the reflex, but considered it a possibility that it might affect it or interfere with it.

Although it might sound like laryngcoeles/air sacs would be a convenient air storage place, there are at least 2 problems : fluids (mucus) entering the air sacs while inverted (upside down) in a dive would likely be difficult to remove, thus potentially infected with bacteria, and, air sacs can be internal or external or both, I think the internal sacs constrict the larynx when fully inflated, not good since they are not well controlled by the musculature. At depth under high pressure and cold temperature, some condensation might occur as well.

So far I'm convinced that their flotation function, associated with stress (emotional, temperature, pressure), was limited to head-up posture.

But then again, Johnny Weissmuller, the olympic swimmer and movie star Tarzan, often beat his chest after swimming onscreen. Gorillas do this while calling, this releases the air from the air sacs. Perhaps Tarzan knew something I don't? Do you think AIDA would approve of chest beating & loud calling after a dive? AaaAaaAaaAaa [sound of chest thumping and elephants rumbling by]

DDeden

 

[wet]

I'll just add a bit more. The thermoreceptors and baroreceptors of the face, mouth, throat are involved in the early part of the MDR empty lung dive.

The chemoreceptors in various places where blood flows through are involved in the next part of the dive. They are affected by the pH changes, as CO2 accumulates, diaphragmatic contractions and/or air hunger due to higher CO2 concentration gets stronger. It is the MDR gasp all over again, but this time triggered internally at the core, rather than externally at the skin surface of the face.

Since most people aren't used to making their blood send O2 more efficiently, we tend to get a "shock" when getting contractions. But the contractions simply move O2 towards the lungs. By propelling while matching these "convulsions" to a frog kick or arm stroke might make them less noticeable and might even adds some extra kick.

DDeden

 

[naiad]

After many seemingly random good and bad static sessions, I have worked out an important factor for my static performance, and possibly for dynamic too. I can do much better when the air and water temperature are both as close as possible. If there is any contrast between warm air/cold water or cold air/warm water, this reduces my performance.

I am happy to have worked this out, as it makes me understand a bit better what makes a good or bad session.

 

[Ol Dirty Diver]

After many seemingly random good and bad static sessions, I have worked out an important factor for my static performance, and possibly for dynamic too. I can do much better when the air and water temperature are both as close as possible. If there is any contrast between warm air/cold water or cold air/warm water, this reduces my performance.

I just wanted to mention that what you just elucidated for yourself contradicts what was found in this study ("...the warmer the ambient air and the colder the water, the stronger the diving response will be."). Not saying that what you discovered can't be true for yourself, but the direct contradiction is interesting.

I only just read this thread. Lucia, you're not the only one who gets cold so readily, and I otherwise experience many of the same obstacles you do. In the summer, the water in Hawai'i is typically > 27C, and even in a 3mm open cell suit I get freezing cold within an hour; I have to dive in a 5mm suit here, which is unheard of in Hawai'i. The reason for my tendency to get cold readily is obvious when you look at me...I have a high BMI, and very low body fat (5.1%). Is this the case for you? Another factor to consider is that having low iron can exacerbate the cold problem. I take iron supplements now just in case, and also because I heard breath-hold training exhausts iron stores (can anyone verify the validity of this?).

My cold problem caused me a serious health problem (immersion pulmonary edema) repeatedly over my initial year of diving. You replied to that thread of mine a long time ago. Many respected users on here contributed interesting, complex theories in my case, but in the end the solution for me was so simple...Staying warm! As soon as I got my first 5mm, the problem went away. Unfortunately, because of my need to stay warm, I can't try many of these interesting ideas that have surfaced involving facilitating getting cold to promote the dive response. I've allowed my diet to go off the wayside for a while (e.g., alternating Pizza Hut and Taco Bell for lunch everyday), in the interest of gaining a little insulation...But alas, I can't seem to gain fat no matter what! (which I think you mentioned). Maybe we have to accept that, genetically, we lack some traits favorable for diving? We may share the so-called "high metabolism", which, itself, would be unfavorable for breath-holding.

But I'm persevering, and planning to try new things. A few months ago I plateaued at a 7:11 dry static (still haven't broken 6 in the water), relying faithfully on the Performance Freediving breathe-up method I learned in the course: long ventilation phase, then "purging"/hyperventilation, immediately before the effort. I now know that this approach blatantly ignores the dive response factors and methods which the FRC followers are elucidating. My few attempts at complete non-hyperventilation breath-holding have been painful and disheartening, but everyone maintains this is what to expect. I heard that one of the very respected divers on this forum sits through 150 contractions, which start very early due to avoiding hyperventilation, in order to reach an 8:00+ static. Also, it seems like this approach to breath-holding promotes much more adaptation (as indicated in this story about Sebastian Murat significantly altering his blood hematocrit through FRC training).

 

[naiad]

I just wanted to mention that what you just elucidated for yourself contradicts what was found in this study ("...the warmer the ambient air and the colder the water, the stronger the diving response will be."). Not saying that what you discovered can't be true for yourself, but the direct contradiction is interesting.

That is what made me think that it is the diving response that is causing problems for me. I do better at dry statics, and my pool statics are best when there is no air/water contrast.

Lucia, you're not the only one who gets cold so readily, and I otherwise experience many of the same obstacles you do. In the summer, the water in Hawai'i is typically > 27C, and even in a 3mm open cell suit I get freezing cold within an hour; I have to dive in a 5mm suit here, which is unheard of in Hawai'i. The reason for my tendency to get cold readily is obvious when you look at me...I have a high BMI, and very low body fat (5.1%). Is this the case for you? Another factor to consider is that having low iron can exacerbate the cold problem.

Glad to know I'm not the only one!
I am quite thin, 173cm/58kg, so that could be part of the problem. I don't have low iron though.

My cold problem caused me a serious health problem (immersion pulmonary edema) repeatedly over my initial year of diving. You replied to that thread of mine a long time ago. Many respected users on here contributed interesting, complex theories in my case, but in the end the solution for me was so simple...Staying warm! As soon as I got my first 5mm, the problem went away. Unfortunately, because of my need to stay warm, I can't try many of these interesting ideas that have surfaced involving facilitating getting cold to promote the dive response. I've allowed my diet to go off the wayside for a while (e.g., alternating Pizza Hut and Taco Bell for lunch everyday), in the interest of gaining a little insulation...But alas, I can't seem to gain fat no matter what! (which I think you mentioned). Maybe we have to accept that, genetically, we lack some traits favorable for diving? We may share the so-called "high metabolism", which, itself, would be unfavorable for breath-holding.

I am not sure about the high metabolism, because my dry static and warm pool static times are pretty good, so I must be able to use little O2. The problem starts when I get cold, or start moving around. These things seem to use a disproportionate amount of O2. A 55m dynamic is more difficult than a 4:30 static.

But I'm persevering, and planning to try new things. A few months ago I plateaued at a 7:11 dry static (still haven't broken 6 in the water), relying faithfully on the Performance Freediving breathe-up method I learned in the course: long ventilation phase, then "purging"/hyperventilation, immediately before the effort. I now know that this approach blatantly ignores the dive response factors and methods which the FRC followers are elucidating. My few attempts at complete non-hyperventilation breath-holding have been painful and disheartening, but everyone maintains this is what to expect. I heard that one of the very respected divers on this forum sits through 150 contractions, which start very early due to avoiding hyperventilation, in order to reach an 8:00+ static. Also, it seems like this approach to breath-holding promotes much more adaptation (as indicated in this story about Sebastian Murat significantly altering his blood hematocrit through FRC training).

Well done with the static times, those are pretty good!
I have also found the no warm-up/no breathe-up method impossible, despite having given it a fair try.