SWB: Reducing the Risk

[amihov]

This conversation is going in a very interesting direction. I want to ask a question. My static apnea is just above 4 min and 30 sec . I have noticed that i can achieve this only if i do warm ups. What can i expect in terms of dept if i have over 4 min static. And how dangerous will be for me short hyper ventilation whit few packs. By short i mean 10 quick breath up just before the dive.
Thank you for reading.
Alex

 

[trux]

10 quick breaths are already quite strong hyperventilation and I'd definitely advise against it. Extremely dangerous! Combined with packing, you can blackout both right at the dive beginning, and at the end (ascent). As for depth, it is hard to tell you - the static time is not really much relevant, and besides your dynamic capabilities, also your compensation technique plays role.

 

[amihov]

I have been doing it for a long time whit no side effects. In general the maximum number of breath ups is 10 . When i do it i get a feeling that i just had a shot of vodka 50 grams and when i get close to this feeling i just stop. It takes me about 10 sec to get to that point. If i do it more i get very drowsy and i lose concentration. So i avoid that. I am not sure how this will work on other people. I will not advise some one to tray this alone in the water.

 

[trux]

Hmm, good way to suicide. Have you ever heard about so called Shallow Water Blackout (SWB), or more precisely called ascent or depressurizing blackout? If not, make sure to look it up. Also enter Hyperventilation in the search box above to learn about its risks and negatives.

 

[Fondueset]

There would be no side effects - just black out. It only takes once.

 

[vali]

i never do more than 4 breaths before static and niether before vertical dive as well....
if i would have a static as you have [4'30"] i think that i mannage to dive somwhere at 25-30 m
as it for now, i can only 15m with 2' static
so i guess trux has got the point here....

 

[tylerz]

My definition of specificity:

Replication, in training, of movement positions, range of motion, movement intensity (frequency, speed & load), movement duration and temporal application (time of day) as found in the actual performance.

Seb, all that makes sense to me as maintenance but I understand it is required to go beyond actual performance in some system(s) employed towards a new performance level. This may require deviating in any number of ways from specificity temporarily whether it be the system performing beyond actual performance or another system. I understand that employing bursts in performance or conditions of stress beyond one's performance objective are neccessary for further development alongside acts of specificity. If you think of your body as a series of systems with subsystems, then it is implied that specificity of performance in one system will require bursts in another system for any increase of performance in a parent system.

As an example of my meaning, if the muscles employed for a deep dive are operating at an optimal efficiency, some power output vs. potential power ouput, then holding one's breath to a lower SaO2 than previously reached may result in a stress that increases breathhold performance while maintaining power performance. The muscles are not neccessarily going to benefit from a slightly longer dive, therefore for their performance to increase they may need to undergo a training that temporarily increases power output vs. potential power ratio. This temporary training will likely deviate in frequency, power efficiency, repetitions, etc. It may also require dropping specificity of other systems temporarily.

Does this match with your understandinigs?

 

[tylerz]

I was training CNF for the last couple months and began having some dives where I would stroke to the surface and my legs and arms would incur a strong sense of fatigue/tingling. I have generally associated this with a good vasoconstriction, however, discussing it with William Trubridge as we were training together, he emphasized that some days he gets this and some days he doesn't. He had not found any significant or obvious consequence of this towards dive performance. However, he did lean towards believing that if he slightly over ventilated this would induce the condition, and also as a consequence of over ventilating, even slightly, put him on the edge of an LMC. I as well did not find a significant correlation between dive result and the sensations, and also began believing it was likely that it was occurring when I ventilated a little more. If the CO2 is less, then combined with vasoconstriction the O2 released to the extremities could decrease and result in this sensation. However, these circumstances for both of us leaves the possibility that our vasoconstriction is not as strong as it could be.

Fundamentally the sensation occurs when H+ builds up in muscle cells. Therefore I think is imperative to understand all the applicable reasons for this condition in order to have an accurate idea of one's individual circumstance:
- vasoconstriction
- low blood O2 saturation
- low CO2
- exercising beyond your anaerobic threshold
- a couple others from online references:
* you do not have adequate concentrations of the enzymes necessary to oxidize pyruvate at high rates
* you do not have enough mitochondria in your muscle cells
* your muscles, heart, and other tissues are not very good at extracting lactate from the blood

So, I think the sensation of fatigue/tingling/burn may or may not be a good thing depending on your individual circumstance. For instance, as described above, a strong argument for those sensations representing an undesirable circumstance is when you over ventilate which hinders the release of O2 from the blood and decreases the intensity of DR.

Another would be that you actually have reached a critical point of hypoxia.

Another would be that you have poor anaerobic ability.

So, where ideally you have these symptoms from an effective vasoconstrction, I don't see any way to determine that this is the case without exploring the individual circumstances. Correct?

PS. I ended up having little to no fatigue/tingling on my deepest CNF dives.

 

[efattah]

Trux theorized that the spleen only 'helps' in subsequent breath-holds. In fact I would say it is the opposite.

During the first apnea, the spleen will release its oxygenated red blood cells into the blood stream during the late stages of apnea, when vasoconstriction has already occurred. So these precious red cells will have their O2 used in the most constructive way.

On subsequent breath-holds, with those splenic red cells in general circulation, their oxygen can be wasted anywhere in the body.

An example is a seal. Typically a seal starts a dive with a non-contracted spleen. In the elephant seal, the spleen releases 24L of blood -- DURING THE DIVE. This is 24L of oxygenated blood....

The spleen effect can be seen on the oximeter. On the first apnea, the decrease in %O2 in the later stages of the breath-hold is gradual. On subsequent breath-holds, the drop is more sudden and linear. I would argue that the gradual drop in the first hold is due to the spleen releasing its oxygen.

 

[shoutatthesky]

Amihov - I am breathing at a rate of about 2.5 breaths per minute in the time before I leave the pool edge for my dynamic. The last breath may be a bit shorter but 10 quick breaths is way too much too quickly. Your quick breath method is called hyperventilation and is something to be strenuously avoided.
I suggest you take a more relaxed approach to your breath up. Don't force anything and you may just find you have a better dive and a safer one.

BE SAFE!!

 

[tylerz]

Actually hyperventilation is defined to emphasize that there is more ventilation occuring whether through increases in frequency, depth, or both of ventilations. Essentially for our purposes, whatever reduces CO2 to levels below tidal breathing. Therefore, even at 2.5 breaths per minute one can be hyperventilating depending on the manner it is achieved and personal circumstances. Remember that each of us has a different ability to ventilate CO2, so "all 10 quick breaths are not created equally" One really has to learn about the effect of a breathing style on their body specifically. I believe to produce the safest and most accurate results we need to begin focusing on how to teach people to detect and determine what works for their body, as opposed to the tradition of passing on arbitrary rules.

 

[shoutatthesky]

I agree. There is no one standard breathing style right for everyone. It sounds to me as though Amihov is advocating quick shallow breaths and it is that old school type thinking I am questioning. I am just adding some words of caution.
I think that those of us aiming to exceed current performance levels are going to have to be educating ourselves in the use of such devices as oximeters, spirometers, expiratory gas analysers, etc. to arrive at some much more personalized parameters regarding breath ups, warmups, and the many other variables that exist. In many ways the term 'hyperventilation' is too general a discription to be of much use in todays freediving environment.
In reality, to say without doubt that anyone is breathing up correctly, there must be some personal parameters established for that individual through the use of these technologies.

 

[trux]

Trux theorized that the spleen only 'helps' in subsequent breath-holds. In fact I would say it is the opposite.

During the first apnea, the spleen will release its oxygenated red blood cells into the blood stream during the late stages of apnea, when vasoconstriction has already occurred. So these precious red cells will have their O2 used in the most constructive way.

Sorry, Eric, but this is misinterpreted. I only disputed the claim that the splenic contractions help with pre-stocking of the oxygen at the first apnea(s). It is clear that the additional red blood cells help with more efficient oxygenation, transferring the remaining oxygen from lungs, but:

1. Unlike at seals, at humans, the spleen starts releasing hematocrit with big hysteresis quite slowly, so that it is usually measurable only after a series of breath-holds and
2. I suppose the hemoglobin stored in spleen is not fully charged (note: I did not find any confirmation or denial of this claim in literature, and am not sure about it, but do not really believe it is saturated with oxygen when not used and stored in the spleen). Hence although its release greatly helps with the transport, it does not help with the pre-stocking, until you can charge it by breathing from the atmosphere (I do not consider charging it from the lungs during apnea for pre-stocking, because it just depletes the available oxygen that could be used without the extra hemoglobin too, just little bit slower and less efficiently)

Hence, on my mind, at humans, the splenic contraction really does not really help at the very first breath-holds. And unfortunately, its help, even at full splenic contraction, is not that great as one would desire.

 

[amihov]

Well about the hyperventilation. I have to say that it is a condition of the human body and it can be felt. How many breath ups we are doing has very little to do whit that stage. It is more like a feeling .When you reache that stage you will feel high. You will feel like your head is spinning. To avoid this condition you have to stop what you are doing. What i do is when i feel the fist symptoms of this condition i just stop. And next time when i am getting ready for a dive i just do less breath ups. I tray all of this in a apnea walk first . Then i go to the pool. And after i have found that it works for me in a apnea walk and in a pool session i use it in the ocean. Right or wrong this is how i do it . I am sharing this because i want to hear other people's opinion .

 

[tylerz]

Hyperventilation is an action, not a state of the human body. As a consequence of hyperventilating you may reach a perceptible condition of hypocapnea. However, in terms of diving, a risky level of hypocapnea can definitely occur without any sensation prior to the dive. I do not think there are any accurate practical scientific methods to determine for an individual what degree of ventilation is the safest, therefore currently it can only be found by trial and error (max attempts with consistent comparison of differing preparation where one method consistently ends in LMC or blackout). I was lucky to be able to witness this sensitivity in preparation recently during Will's training for his world record attempt.

 

[shoutatthesky]

Tyler, in your training with Will how many of these incidents of LMC or blackout did you witness?

 

[tylerz]

A handful.