Sambaaaa !

[trux]

Originally Posted by adolphin

Plus, if I am not mistaken, isn't the hyperventilation as a term descripes FAST SHALLOW breaths, which will decrease CO2 level in blood SHARPLY without increasing O2 levels? while DEEP SLOW breaths will both increase O2 level and decrease CO2 level but NEVER to the extend of delaying the body reflex toward higher CO2 levels?
I was doing very very slow and very deep breaths for about 20 minutes before standing up all of the sudden.

Ah no, in this case I was right. Hyperventilation is any kind of ventilation above the normal, while hypoventilation is below the normal. Hyperventilation may be slow and deep, fast and deep, or just fast, and in some cases even fast and shallow breathing can lead to reducing the CO2 level, but shallow breathing is rather going to cause hypoventilation (CO2 excess - this time I mean it ).

What you did is typical case of rather strong hyperventilation and a definitely bad thing for freediving, because of many reasons. I already posted about it recently several times, so do not want to repeat it all, but you may want to look at the other threads about hyperventilation. Let a moment and I'll add some links here.

This is the recent discussion: http://forums.deeperblue.net/beginne...reathe-up.html
And this is an older thread: http://forums.deeperblue.net/static-...-good-bad.html
This post sums up more of the negative effects of hyperventilation: http://forums.deeperblue.net/static-...tid#post626123

However, there are many other threads about hyperventilation in the archive. I strongly discourage anyone but the top freedivers to apply hyperventilation of any level for improving the performance. And as I stated in the other thread I believe that hyperventilation is counterproductive even at top freedivers, but that is my opinion and would need to be scientifically confirmed first.

Originally Posted by adolphin

It is very clear in my post that the major reason for the dizziness in my understanding is the sharp drop in blood pressure, which you agreed that is an accelerating factor.

Actually the major factor causing the blood pressure drop, carotid contraction, and reduced oxygenation of the brain was the hyperventilation, the standing up was secondary - swimming underwater or other physical effort would have similar effect. And doing this before a dive is really a big no-no.

[adolphin]

trux, now that makes alot of sense .. thanks alot ..
I went through the first link :"Breath Up" .. it was very informative.. I would surely eat up the other links shortly ..
One point to mention here trux about the accident I had (LMC or BO) with sands, actually it didn't happen without any sign! I had the air pursting out of my mouth in small amount forcefully because of the strong urge to breath near the end, my chest muscles was contracting too badly that I couldn't hold the air in my lungs, I spitted out pockets of air about 4 times as I remember before I lose conciousness ! .. I'm sure the first purst is a clear sign of exiting for those who know (in dynamic and static not deep diving).. I'm surely a very stubborn person who could withstand alot of pain (not good at all because accordingly I need to depend upon my conciousness to deside when to quit rather than my tolerance to pain or discomfort).
According to all this, I think that the breathup on the time of incident wasn't hyper, I was only very new to doing pass the limits, I thought that when CO2 is too much high (that usually is way before O2 is too much low) I would unwillingly swim out of water to breath, that wasn't the case with me. Maybe also the gym exercise I did was still eating up O2 too fast, what do you think?

On the otherhand, I did experience hyperventilating in dry statics last year, well I understand now it was extreme coz the tingling was all over my body !!! it remained for long period (I assume at least 1 minute) before I came back to normal and the contractions didn\t start before 4' 30" or so ! so I made 5' 26" at that time, I didn't stop the static because of too much urge to breath, rather I was shocked by the time it took because at that time I was doing increments of 10 sec a training, that day it was 1' 30" over so I was quite happy with it .. .. I assume if I desided to continue I would have B/O ! .. now I understand that this was not my PB since it was done through extreme hyperventilating (which I consider a violation and upnormal situation), therfore the 3' 30" I do without those symptoms is a real PB.

[adolphin]

After reading the other links trux (which are very informative-thank you) .. I have one point unexplained for me .. I do understand that the O2 saturated in the tissues could be utilized without problem even with hypervenilation and strong O2 binding to hemos since it is already inside the tissues (correct me if I'm wrong) .. but O2 delivered from the lungs to the blood into the brain and other body parts will be of a very low exchanging rate (due to the strong O2 bindings to hemos) .. knowing that the brain consumes it's O2 reservoir so rapidly (it takes usually less than 10 seconds of no O2 supply for the brain to shutt down it's operation to save its cells) .. then it should only be true that: Extreme Hyperventilating=Fast Fainting (BO) .. while as I mentioned earlier that when I hyperventilate extremely last year (know it from the extreme face-hands-feet tingling feeling for more than a minute) I did 5' 26" !!! .. I understand that it delayed the CO2 reflex in the body, but how on earth with a very low O2 blood exchange in the brain could the brain still work after 5 minutes ?!! ..any explainations ?
Second question: if the case is not very extremely so (O2 will still be exchanged good enough to keep the organs, specially brain functioning) then wont the body accumulate CO2 while holding breath so it would reach the level that alkalinty will go back normal and the BIG amounts of O2 bound to hemoglobin cells will get normally released and the breath holder will hold his/her breath safely for much longer than normal ? .. if it is so, then I assume that the case is specifically dangerous only when the body will have activity that would overpass the rate of O2 exchange of such state causing BO, but as long as the activity is below that level (say in case of a static with very low metabolism rate - that is low enough for the given example .. ) then there will not be a risk of BO ! .. I do understand though that this will be a very risky game, but just, is my understanding acceptable according to the diving theory?

[trux]

Adolphin, you probably did not read all the info in the threads. It was explained there too. The body reacts with several ways to the hyperventilation, but the carotids constriction together with the high O2 binding may be already sufficient (depending on the level of hyperventilation and few other factors) for hypoxemia in brain high enough for a blackout. But of couse (again depending on the level of hyperventilation), the brain may continue to work, the CO2 level slowly rises up to the normal, (while O2 drops below normal). Due to the normal CO2 level your brain still thinks you have enough oxygen, so you can make a longer apnea without big effort, but may be already in a really dagerous hypoxic zone and black out easily.

Also, in your calculation you somehow count with a constant O2 consumption. That's not the case in apnea. Normally, at a trained diver, the consumption drops very rapidly due to the diving reflex (bradycardia, blood shift, blood shunt, vasoconstriction,...) and relaxation. Although after the hyperventilation your brain may be starved of oxygen, the body continues to consume it, and does not get any signals to start the diving reflex. Later, already deep in the dive, hypoxemia may already slowly start, but your acidity now gets just about normal, hence both body and brain consume the max, not knowing they are in apnea, hence not trying to save. When the CO2 finally rises, it may be already too late and you black out. And even if you don't, the diving reflex will be too late and too soft (if any at all). So in total you waste more oxygen than if you dive with normal CO2 level.

[DiverTodd]

Speaking from experience, adolphin, it definately sounds like your day was a bit FULL before you even got to the pool! I learned the hard way (via a poor performance) to keep my freediving pool nights free of ANY other exercise, including swimming, tolerance tables, etc. That way, all of my energy reserves are still intact for my attempts in the pool that night. I also make sure to eat a LIGHT dinner, at LEAST 4 hrs before I head for the pool, so my body has digestion out of the way and isn't using oxygen for it. My dynamic distance has bumped up into the 65m range (from 50m), and this Tues, I'll be going for 75m. I KNOW I can do it, I just have to relax and focus on my kicking!

Todd

[adolphin]

Ok trux maybe I couldn't get the idea to you, I understood that it depends on the level and extremety of the hyperventilating, I understood that when it's extreme then a black out should occour almost instantly because no fresh O2 will be delivered to the brain other than what it already has, just before apnea. Is this understanding correct ?

Then I already descriped my condition last year, even before I start the apnea I felt extreme tingling in my face my hands and my feet and after I went into the apnea I still felt it very strongly for more than a minute before it started to lower in intensity over the second minute, now how extreme in you ropinion is this hyperventilating? .. and to know how did I reach to that state it would be good to know that I kept on breathing all air in then all air out (lower abdomin together with chest and back) for the whole 5 minutes of ventilation, very very intensive deep breathing but not fast (5 seconds inhale 10 seconds exhale with no pose) .. now if you could go through my last post and see if you have a resonable explaination of how could I (under such state) do a 5' 26" apnea without BO ? ofcourse it was dry static, so if it is imposibble in theory then the only posibbility I would suggest is that I actually blacked out for some time and got back to conciousness and just had a memory loss! but then would I be still holding my breath when I come back to conciousness and actually have all normal feelings of apnea including the start of urge to breath again which made me look at the watch to see surprizingly and for the first time in my life that I reached 5' 26" and that's when I resumed breathing although the contractions was only at its begining (yet mild).. what do you suggest ?.. .. and thanks for giving me of your time and effort trux.

[trux]

Originally Posted by adolphin

Ok trux maybe I couldn't get the idea to you, I understood that it depends on the level and extremety of the hyperventilating, I understood that when it's extreme then a black out should occour almost instantly because no fresh O2 will be delivered to the brain other than what it already has, just before apnea. Is this understanding correct ?

Yes, adolphin, defintely, it can indeed happen.

Originally Posted by adolphin

Then I already descriped my condition last year, even before I start the apnea I felt extreme tingling in my face my hands and my feet and after I went into the apnea I still felt it very strongly for more than a minute before it started to lower in intensity over the second minute, now how extreme in you ropinion is this hyperventilating? ..

On my mind it was already rather extreme hyperventilation.

Originally Posted by adolphin

and to know how did I reach to that state it would be good to know that I kept on breathing all air in then all air out (lower abdomin together with chest and back) for the whole 5 minutes of ventilation, very very intensive deep breathing but not fast (5 seconds inhale 10 seconds exhale with no pose) .. now if you could go through my last post and see if you have a resonable explaination of how could I (under such state) do a 5' 26" apnea without BO ?

With hyperventilation you can indeed achieve impressive times, because you can go further with less effort, but you cannot really tell how close to BO you are. You were likely lucky to still stop before you got to that point, but the next time you try you may have less luck. The CO2 still grows at the end of a hyperventilated apnea too, but the curve is different and the security margin too narow and too irreliable (because it may differ in every case). And if you did the same before a real dive, you'd be probably BO'd.

[trux]

You may want to check for example these links. There is much more (and better) info on the web, but this is a good start:

Shallow water blackout - Wikipedia, the free encyclopedia
Hyperventilation - Wikipedia, the free encyclopedia

[adolphin]

Speaking from experience, adolphin, it definately sounds like your day was a bit FULL before you even got to the pool!

Oh yes Todd, I totally agree with you that my program that day wasn't good for static and surely not for dynamic (besides a trial to do a new dynamic national record !! .. )
Now after my very first experience with real training I am surely not going to do the same again, on the other hand I kept the 4 hour rule for food .. at least I didn't break that one, otherwise I could have blacked out as soon as I jumped into the pool ..

My dynamic distance has bumped up into the 65m range (from 50m), and this Tues, I'll be going for 75m. I KNOW I can do it, I just have to relax and focus on my kicking!

Man! great work, keep up the spirit, and keep around the safety buddy .. and safe margins too, you don't have to ask a Doctor BUT ask a SAMBA PLAYER ..
All the best .. and dive safe

[adolphin]

Originally Posted by trux

You may want to check for example these links. There is much more (and better) info on the web, but this is a good start:

Shallow water blackout - Wikipedia, the free encyclopedia
Hyperventilation - Wikipedia, the free encyclopedia

Ok trux .. I've read the hyperventilation link already before, I'll read the shallow water black out one .. thanks ..
you are keeping me busy now aren't you?! otherwise I would keep on writing toooo long paragraphs ha? .. quite smart .. .. JK ..

[adolphin]

trux,
Hi there ..
Interesting for me to know that BO when ascending from deeper than 10 m is not SWB but rather DWB .. although the BO happens in the 10-5 m depth .. while shallow water black out actually needs to take place completely in water shallower than 10 m .. and the mechanism is different too ! .. interesting.

I am still reading in the references .. and shall practice more to experiment ( on no no not practice hyperventilating .. .. but practice not to hyperventilate and what times can I make .. )

[trux]

Originally Posted by adolphin

Interesting for me to know that BO when ascending from deeper than 10 m is not SWB but rather DWB .. although the BO happens in the 10-5 m depth .. while shallow water black out actually needs to take place completely in water shallower than 10 m .. and the mechanism is different too ! .. interesting.

Yes, that's according to the definition in WikiPedia, but if you ask any diver, freediver or spearo, they will tell you that SWB is exactly what in WikiPedia is called DWB. Historically taken, both terminologies are wrong, because the term Shallow Water Blackout / SWB was first used by doctors studying blackouts of rebreather divers in early diving era, which were in no relation to freediving hypoxic BO. So when speaking about SWB, and from the context is not clear what type is meant, it is always better to specify if you speak about simple hypoxic blackout, or a hypoxia amplified with the depressurizing effect during ascent. However, here on DB, when people speak about SWB, they always mean the one called DWB in WikiPedia (hypoxia on ascent due to the pressure gradient).

[adolphin]

.. You know trux .. this kind of undifinit terms cause alot of problems and prevent us from evolving ! .. just imagine your self talking about apples while I talk about oranges and we both THINK that we are discussing the same thing, that takes alot of energy and lots of emotions sometimes,for no logical purpose !! .. if we were lucky enough, one of us after say couple of years will say to the other one: " Aaaaaaah! so that's what you were talking about ? .. no no, I was talking about that thing actually!" .. and hopefuly the new discovery is acurate, not a new loop !! ..

[trux]

That's right. I already brought once the WikiPedia definition to a discussion here in DB, but it was met with unanimous resistance, and I do not think you will bring freedivers to using the SWB and DWB terms in the way defined in WiKi. That's why I mentioned it is better trying to avoid the term altogether and rather just specify whether you mean plain hypoxic BO, or a BO due to the depressurizing during ascent.

[adolphin]

Got your idea trux ..
It reminds me of some Mexican dishes which name is actualy the recipe itself! quite long, but can't be mistaken ..