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Diver vs Doctor

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.

For better or worse, I have come here to clear up a few misconceptions. I am not here to indulge in endless circular arguements. Some of this I posted on Diveoz, but I thought it might as well come directly here.

Let's get a few things clear first.

I do not have any problems with the concepts of marine mammal diving physiology. There seems to be an impression that I disagree with aspects of the accepted and published science of diving by these animals. I don't. However, I do disagree with some of the assumptions that have been made about replicating these characteristics in humans, but I don't wish to provoke discussion about that at this stage.

I do not have any problems with the diving. I am known for radical diving myself.

I do not have any problems with interested divers utilising the exhale technique. Clearly it works, to this point, in a group of focussed exponents anyway.

OK, so what do I have a problem with? It is the way that discussions about this technique in my part of the world have been embellished with "plausible" sounding pseudo-science (I will justify this statement below). Why is this a problem? Well, there are members of the diving public who take what they read on these sites very seriously indeed, and adjust their practice on the basis of this information. It follows that we all have a very real responsibility to present information accurately, and if there are no firm facts to report, then we should admit that we don't know. We must not allow our exuberance or enthusiasm for a technique to seduce us into implying we know more about it than we do. Call me a pedant, but I have been around divers for more than 30 years, and I understand the way their thinking is influenced.

This is what brought me into conflict with Sebastian. I am almost prepared to admit that using "complete fool" in relation to him was not the most tactful way of opening the account, BUT, as someone who dedicates a lot of his time to providing divers with accurate information, I get very angry when I see potentially dangerous (I never said they definitely were dangerous) activities or methods promoted to the public on the basis of incorrect or only partly correct science.

I do understand that participants here will bristle at my claim of incorrect science. But as I said on Diveoz I shall provide the opportunity for one of you to slam dunk me with his better understanding of the field:

I refer to Dr Gowland, whose acid wit has been visited upon me, and who is a recognised expert in the effects of pollution on mussels.

Ben, what I would dearly love you to do for me and your adoring audience here, is to explain in clear and accurate physiological terms how this statement from Seb works in relation to preparation for a deep dive: He says...

"Moreover, exhaling promotes venous return which in itself hastens the rate of O2 diffusion, greatly enhancing venous O2 stores and reducing the arteriovenous O2 difference. This all happens before submersion. Inhaling counteracts these effects."

I contend that this is absolute physiological rubbish, and I have chosen it because it describes an issue pivotal to the technique, (it would seem) and it is typical of a number of statements he has made.

As a former physiologist, I think you know what I am after: a clear step by step breakdown of cause and effect. You know the sort of thing ... " On exhalation from TLC there is a change in intrathoracic pressure from x to y. This results in ...blah blah" This should not be hard because as Seb says, all this takes place before the dive, and the physiology is essentially basic cardiorespiratory stuff (with a bit of head out immersion thrown in) and it's in most of the books. Now, if you can explain it clearly in these sorts of terms, I'll crawl back into my hole and never bother any of you again. It would appear from your earlier posts that you were keen for such an opportunity. If you can't, then all I'm after is an acknowledgement that there may be some problems with the way "you guys" are presenting the basis for your activities to the wider diving community. This has been my only point all along.

Over to you.
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Gowland being more polite than you have probably ever seen!

I'd like to extend a welcome to Simon and hope that he can stay for longer in the DB forums than this topic alone.

I am/was known for my propensity for ranting hence some of my comments above. These forums are quite a community and hence most of the people that read my comment know of its specific relevance to me (which I of course appreciate that you wouldn't).

As I stated above, I am mostly in agreement with your safety concerns. So I can appreciate why you began this debate.

The main umbrage that I took (it has subsided into slight depression now) was your use of highlighting your status to try and prove your point. I find this most distasteful (possibly because I am a 'pomme' ;) ). Having done a PhD (on marine pollution, as your search identified :D ), the process of doing so highlighted to me that degrees mean very little, and that having in depth knowlege of a sister subject does not make you a better expert than a non-scientist who has a great deal of experience in the matter.

When I first got involved in Freediving, I took an arrogant stance that I would know more than most around me due to my studies of freediving mammals and in human/sports physiology. At first this was probably true, but then I unearthed a great community with exceptional understaning of the physiological issues associated with freediving. I found that here on DB, and on an email group called 'apneadiver' that I was invited to join. Since then, time-and-time again, I have met numerous scuba-medics who arrogantly assume that they know more about freediving than all these intelligent freedivers (until they read through these forums). I was especially interested by your past in MM research, as I consider that to be far more relevant to this subject than Scuba physiology.

As a different side of your character is appearing to us now from us adapting to your writing style, I hope that you do stay around these forums to help out with info as well as learn something from time to time.

Now - here's the bit you'll like - in your defence, I completely understand where you are coming from with your specific point above

"Moreover, exhaling promotes venous return which in itself hastens the rate of O2 diffusion, greatly enhancing venous O2 stores and reducing the arteriovenous O2 difference. This all happens before submersion. Inhaling counteracts these effects."

Having spent several years reading emails from Sebastien, I have become accustomed to the nuances of his 'speech'. I read the above as:

Exhale diving quickens the onset of bloodshift. Having a thoracic blood shift allows you to oxygenate more blood that is stored locally, reducing the difference between venous ppO2 and arterial ppO2. This starts before the main dive (by immersion, special breathing and empty lung prep). Inhale dives force blood away at the start of the dive due to packing and retain as normal arterial:venous O2 ratio.

I could paraphrase the above in more medically appropriate language, but I think that would be non-beneficial to this forum as is it our responsibility to speak in plain English (another point of yours that I agree with, and one of the reasons why Sebastien's post was inflammatory to you).

Now - I can quite understand why it can be read as:

Expiration promotes venous blood to come to heart (which is wrong), which speeds up O2 absorption (which it wouldn't), enhancing Venous O2 stores (which it wouldn't). This happens before getting in the water (which is nonsense). Inhaling does the opposite (which is not true).

So there you go - all this comes down to the use of English.

The outcome of all this banter is probably beneficial. Your warnings may well be heeded by those who are inexperienced in the knowledge and practice of deep freediving, and those who are practicing it will continue to do so until such time that Sebastien's research is published, and then the techniques could possibly become more mainstream.

With regards to 'Nature' magazine - we should wait for Seb to publish his research there - as I know he plans to do, and I wish him every success in that and his PhD thesis. After all this furore has subsided, you may even be kind enough to offer to proof read his manuscripts for him for correct use of terminology - and I mean that seriously - I would offer to do the same.

Regards, and welcome again,


Thank you for your honest and candid response, which prompts me to clarify a few more things.

It is very rare for me to ram evidence of my own perspicacity down an audience's throat. Indeed, like you, I usually find such displays very distasteful. Unfortunately, there were so many "who is this idiot" comments firing around that I felt forced into it. At the risk of sounding like I am doing it again, allow me to say that this is not a hobby for me. I have worked full time in diving and hyperbaric medicine for the last 14 years. However, I do unreservedly acknowledge that this, of itself, does not automatically confer expertise in free diving.

My particular interest in free diving comes from my background in MMs. I studied Hooker's Sea Lions in New Zealand and with a team assocated with Gerry Kooyman's lab we were the first to attach TDRs to these animals and characterise their diving pattern. This was extraordinarily interesting stuff, and we did it in the early 80's when instrumenting seals was still relatively novel. The anticipation of retrieving the data from the first few animals was excruciating. They were diving to 200 - 400m in a 4 minutes down 4 minutes up pattern non stop for hours at a time. Gerry was right in calling one of his early books "Weddell Seal - Consumate Diver" but the Hooker's Sealion was pretty amazing too.

I fully appreciate and admire the ingenuity and intelligence of members of the diving community. I don't doubt that many of the individuals I have been trying to debate are smarter than me. But one of the problems I frequently encounter (back to the pedant thing again) is that divers (and I'm not talking about free divers or any person in particular here) without formal training in science often don't understand the need for precision and accuracy when presenting some of their ideas, or the bounds of acceptability for drawing inference from observations. This is an anathema to someone who dedicates large amounts of his time to trying to prevent further debacles like the ban on moderate reverse dive profiles that pervaded the scuba diving community for years. This is a good example of a fallacious rule that arose out of well meaning but misguided inferences by "amateur scientists".

This need for precision in communication is highlighted by your demonstration of how Sebastian may have actually produced a statement that essentially said the opposite to what he was trying to say!!

Look, that was how the arguement started, and that is the way I would prefer it to end. If Sebastian wants critical review of any material he wishes to promulgate or publish, I would be only too happy to help out. This is what I suggested in one of my Diveoz posts.
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You wrote:
….he fails to acknowledge that whales and seals can afford to exhale prior to apnoea because they have VAST stores of oxygen in other places (mainly in the form of oxy-myoglobin), just to mention one of many physiological adaptations that humans DO NOT HAVE.

I certainly don’t think we could ever compete against these mammals and I don't believe I claimed that but, I certainly think these attributes can be developed to make a difference in our diving abilities.

I never implied doing away with oxygen stores. All I said was that I thought it could possibly be stored in other ways, i.e., by the blood through “immediate” adaptations. Furthermore, I would suggest these stores can also be developed through long-term acclimatizations, e.g., hematopoiesis and myoglobin

Your experience cannot be translated directly to the general free-diving population and you should be at much greater pains to point this out instead of trumpeting it as a revolutionary new technique…………..Your argument that you enhance your non-pulmonary stores by exhaling, improving venous return, and thereby “hastening the rate of O2 diffusion, greatly enhancing venous O2 stores and reducing the arteriovenous O2 difference”, all “before submersion” is nonsensical. Mixed venous oxygen content is determined by the arterial oxygen content minus (tissue oxygen consumption divided by cardiac output). Your arterial oxygen content will be the same whether you exhale or inhale immediately prior to a dive. Your tissue oxygen consumption is not going to be altered, and there will be complex effects on cardiac output, but none of it will result in a pool of well oxygenated venous blood as you imply.

As Ben suggested there has been some loose usage of non-standardized terminology, at least in the diving fraternity, that has contributed to the controvers; I just assumed you were familiar with the lingo. I haved studied physiology at university and I do know better. Please correct me in its usage if I misuse it as I'm sure you are more learned in this respect than I. Anyway moving on.

This is what I suggesting (I'm sure Eric and Tyler think the same way on this), when I refer to exhale (expiration) diving: I don’t mean a single respiratory cycle but instead imply a series of expiration dives with lung volume at functional residual capacity FRC (Wet).

What I’m suggesting is that expiration diving promotes greater centralization of blood volume (venous return) than inspiration diving. I base this view on the works of, but not restricted to, Lin 1984; Agostini et al. 1966; Buono 1983; Dahlback 1975; Hong et al. 1969. Furthermore, I would suggest that this centralization effect does not greatly dissipate after such dives. This is based on personal observations (not published).

Depending on initial lung volume, depth of dive and duration it can take none to a few warm-up dives to accelerate and magnify the above effect (I say none if training is based on E. Kendal's work on sensitization. This is a recent, personal and extreme observation...for another day perhaps). I include the following observations as evidence: (1). complete airway closure immediately upon surfacing from a dive which prevents spontaneous involuntary ventilation. Closure is so strong that it can take considerable effort to open the airways, much like the effort required to pop-open a ballon. Typically, this extreme condition only occurs if pre-dive expiration is carried out to less than about residual volume (RV); this is achieved by “reverse packing”; (2). buoyancy at the surface significantly decreases from the beginning of a session to the end, when measured at a lung volume at say FRC; and, (4). a more accelerated recovery between dive bouts which tends to imply rapid gas exchange due to an enhanced venous return; and, (1). a feeling of “fullness in the chest”, post-dive.

On the other hand, based on my experience and that of others undertaking inspiration dives, especially after buccal pumping (“packing”) these effects are not evident or attenuated possibly because intrathoracic “chases” blood out of the lungs so that pulmonary capillaries do not become engorged as they would on expiration dives.

How would this response effect blood O2 stores? A more homogenous perfusion of the lung hastens the rate of O2 diffusion (Turino et al. 1963). If tissue metabolism does not increase but oxygen diffusion increases this could manifest as a reduced arteriovenous blood oxygen difference and thus, enhance O2 stores. This situation is not perhaps too different to changing posture from the upright to the supine in which reducing one’s lung oxygen stores enhances venous blood oxygen stores (Loeppky 1975), all but in a much more extreme form during expiration diving.

The above changes are only transient changes and do not include potential and longer-term intramuscular and haematological adaptations and, an altogether different issue.

I never implied that this strategy was appropriate for variable-ballast freediving. As we all know, variable-weight freediving is a technical and unnatural discipline and, I would be the first to admit. From an experimental view point it has implications of being better able to elucidate the mechanisms of gas exchange at depths where the lungs reach less than residual volume. Might I also suggest that that simple duration is not the most important factor in a variable-ballast freediving. In my experience and no doubt that of many other exponents, extreme dives, like in the animal realm are executed anaerobically; the limit in such cases can be due to limitations in anaerobic capacity of the locomotors.

You suggested that my technique MAY have some merit for limited depth dives at constant ballast (because of the energy savings he describes) but you would be doubtful about even that.
If it wasn’t, I can assure you I would not switch from inhale diving to exhale diving unless there was some energetic gain. I may be out on the edge but I’m not that foolish! All I’m doing is prolonging the sink phase since active drag related energy losses are largely diminished. Glide duration is correlated with diving depth (Williams 1999). Indeed, I can’t see anyone asking any deep-diving (human) freediver to swim the entirety of their descents during a maximal dive. As any diver knows, the rule is: you don’t work if you don’t have to and better if someone (i.e., the environment) is doing it for you.

You would advise great caution in adopting these techniques based on the experience of a single exponent………..Do I have any observational evidence for immediate short-term adaptations in the elderly, females and novices? Yes, two middle-age men in their mid to late fifties with 20-30 years spearfishing experience; one male and one female (35 y.o and 31 y.o.) with no prior diving experience. Each had a max bottom time of ~1’00’-1’30” using the conventional strategy but were able to equal these times with ease, in their first dive session after 3 warm-ups. This is with little to no possibility of longer-term adaptations. Moreover, dives were mixed involving both the inspiration and expiration strategies.

I am not a single exponent. A portion of the general freediving population, e.g., competitive sport freedivers, are already using this technique, all but maybe in an attenuated form, for routine warm-ups before their performance dives. Then again, there are others who’ve begun to specifically develop such capacities with good results, I hear. This technique, although radical, is no longer fringe.

We’re not claiming to be scientists using the scientific method but if you gve me another year or two I might be. Perhaps these diving strategies are not obvious to you, you may not be aware of them untill recently, but they are to me and others who’ve been sharing and comparing experiences. Should we not mention compressed gas narcosis in inspiration freediving since it’s never scientifically been proven? Should we not teach others about it’s risks? Sometimes, not always, but sometimes, it makes me wonder whose more appropriately trained and qualified, the educated diver with extensive first-hand experience or the hyperbaric physician who tells me I’m an asthmatic and am not fit to dive or perhaps even the respiratory physiologist who tells me that its not possible to increase one’s lung capacity beyond vital?

The “quote” regarding Graham read as “Dr. Graham Simpson and I prefer to think that we only know 1% of everything there is to know as it certainly allows room for alternate possibilities and future learning”. I fail to see how that constitutes endorsement or agreement by Graham. We became involved because he was open to a world of possibilities. Indeed, he may well disagree; I believe his personal view is one for a more pronounced dive response. But then again, what constitutes a dive response:a redistribution of peripheral blood flow and centralization of venous blood volume, amongst other things. This response is not an all or none event but one that is more graduated than believed; indeed, as soon as you immerse your feet. Graham, from our many discussions knows quite well my personal views on this, which hasn’t stopped him from being involved in this project. I don’t believe it is necessary to engage the services of Claes Lundgren when Graham and I have already made plans to confirm or otherwise refute these theories. As evidence that I bear no ill-feelings or grudges I extend you the invitation of co-authorship if you'd care. The invites extends to you as well Ben, Eric and Tyler. All your valued contributions would be be most welcome.

To more constructive days ahead.
Sebastien Murat
Towns Vegas or was that Mt. Isa on-the-Sea?
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PS: In regards to being prepared to concede that I may not be a “complete fool” I thank-you and I’m sure that you are not perhaps so arrogant as I thought you to be. As I am presently sitting for some physiology exams and time is rather short, I beg you to temporarily excuse me for not supplying you with the relevant reference list with this post. A transcript from the Catalyst program can be accessed through their online archives.

Oh! and don't believe everything you read or hear....it's the media for god sake!

Once again, sorry for my every long posts. Let me first summarize why I think the following post is relevant:
If we are not accurate about how we discuss, we will continue to have these aweful accusatory discussions that drain credibility from each other, prior to exploring the concept in full. We can be accurate in how we discuss if we can recognize where the inconsistencies and inadequacies of our discussion exist. So the following I hope partially aids in this, and alleviates some of the credibility drain that was so easily thrown around.

Simon et all,

I think the concern of the danger to the public, is not realistic (my opinion). I just can not see a difference between somebody talking on the news about freediving and all their explanations, and that of Sebastien? Please somebody help me to understand the distinction, which I am very open to discovering? Whenever this general public sees a show on Freediving (lots lately) they hear a bunch of summarized statements, speculations and theories, about what the freedivers are participating in, all which according to the approach of reasoning I have seen so far in DiveOz, should be condemned as well. The general public has no protection from themselves regarding the concepts and theories expressed during those media exposures. It really looks like you guys are mistaking the general public, with the intermediate freedivers. I think the only people who would actually be at a disadvantage with Sebastien's quotes, would be the diver that already understands the basics of freediving, has become confident in the activity, but is not in touch with listening to their body. That is the type of person that has confidence and blindly tries the next greatest idea, without watching for their limits. Is that Sebastien's fault or a fault of the diver? I can only say the diver, because they can and will make the same mistake with freediving concepts that have been around for ages and do not seem to be coming under the scrutiny of this discussion. So the only disadvantage comes from the fact that there is another thing that this type of diver can participate in, that can cause further danger that the ones that already exist. It is inadequate to just claim it is the unknown dangers that are the problem here. Freediving is unknown, the activity is different for every person, the basic rules are to try things gradually, with lots of safety, and listen to your body. I repeat, help me distinguish the new danger presented?

...need for precision in communication...
Thanks for your earth-grounded communications in the posts here at DeeperBlue. If you were to every search through many of the posts here, you would definately find that most of mine focus on the accuracy of arguments, wording, and logistics towards discussion. So, as much as you may not be interested when you heard it from me in DiveOz, you are now announcing it yourself, and I hope you can appreciate that a little more now.

As well at DiveOz I repeatedly asked questions to understand how the ideas of Sebastien had relevance to your codemnation and the public. Why is this not obvious to me? Because you seem to assume, that an explanation of confidence is known to be received by the public as proven science. I ask you again for quotes of Sebastien where he has clearly announced his intention to provide proven science for his end conclusions. All I witnessed was many summary statements from him, about what his theories are based upon and where one would need to look for the source of these ideas.

So, if we can agree about that, then your lingering issue seems to be that the public might misinterpret his confidence as proven science. Well I can guarantee that when we look around at similar circumstances, we find all around us ideas of confidence being expressed, some becoming science, others being proven wrong, and others never being known other than through experience.

The point of value that I hope you can see and maybe agree on, is that a large percentage of people do not wait or cares for the scientific proof and often do not expect it to every come. Therefore, it is presumptious, to assume everything is interpretted as science, and everything of confidence towards theories must be. You have a right to announce your concerns with the theory, or challenge points, both of which would provoke much interest in people sharing as much perspective on where the source of the theories are. But by announcing that nobody has a right to say anything with confidence until there is proof, then you have destroyed the discussion and the exploration at the onset.

If you look at most of your initial posts they narrowly imply the following, "Sebastien is trying to say this is proven and if he can not provide a journal reference, then shut up, and nobody should listen to this person." That immediately kills the reason to discuss it further, since you are narrowing the audience of interest towards Sebastien's theories, to those that are not going to wait for it to be proof. It also implies if he does not have journal references then it is hog-wash. It also implies Sebastien's intention to come across as a scientist and a person who believes this is a proof. And most importantly you have made a case for anybody who relates more to you than Sebastien, to stop any further exploration of where he is coming from, of which he has not even shared yet. All of these things are false or unfair. That is why you are the source of opening up the argument of what the relevance of science is here. You can still explore a concept to discover the likelihood of its existence, without it being in a journal. Yet, you showed no interest in looking up the references to freediving that, quite easily, make it clear as to where these theories come from.

Why is it the responsibility of Sebastien to teach everybody who asks, everything about freediving, so they can have the background infromation into where his theories come from?

We all have the responsibility in discussion of trying to understand where the perspective of the other person comes from. Which is not the same as saying, "If you don't subscribe to my perspective, then you are irrelevant."

As far as choice of wording goes, you have to understand that any summary of a theory (and any interpretive language), is going to hold a great degree of ambiguity, as it is trying to represent a whole, with only a piece. So what you ask for as clear communication is impossible, unless a person is willing to write as many words as you require to get the meaning. Any person skilled in the use of language and communication is, or should be, aware of this basic fact. You rely on assumptions to communicate, just as much as Sebastien, so no he is not in error. He assumed how much background information to supply and in which words would the message get across (more likely what background information would you require to discover what he means), whereas you took it as a complete explanation with your interpretation.

I am glad Ben has offered you another interpretation of Sebastien's quote and that you find it more understandable.

At the end of the day, I believe it can be further discussed as to how likely it is that the theories are correct, that it will not be proven due to lack of interest by those with funding, that Sebastien has a right to announce what his theories are, that he does not have a responsibility to only present proven facts, that he does not have a responsibility to put a disclaimer on every statement, that he will always be misinterpretted, that most interested in this subject will learn from their bodies what works and what doesn't, and many will want to learn from Sebastien.

I do not see a danger to the public above any that is already existent in the current form of freediving.
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I see great potential for us to go round and round in circles here, and I doubt that neither you nor I have the time for that. My point is subtle perhaps, but it is important. Maybe it is easier for me to see because I interact with divers seeking further information on various topics all the time (I would answer 5 - 10 emails a day in this regard). As a result, I see the consequences of misinformation (not referring this free-diving in particular here) all the time, and it is very frustrating trying to undo it.

Much of what you say above about the inevitability of misreporting by the media etc is correct. I also agree that it is ridiculous to expect that Sebastian will not or should not want to advance his theories in public. That is OK too, BUT it is the way he (or anyone else in a similar situation) does it that is important. I have to say that Sebastian's website page on freediving fails to properly communicate the essentially experimental and unproven nature of his methods. It would not take much to make it right, but it is not there at the moment.

You must remember that Sebastien is a bit of a star in this field, and people will take what he says very seriously. It follows that he must be careful how he expresses things. As you have seen above, Seb wrote something that was basically physiological nonsense in THE WAY IT WAS WRITTEN. The fact that there was an alternative explanation which makes more sense does not fix the problem. I agree with you that the at risk group here is divers with some limited experience who might try something with a little less caution when one of the gurus implies that it is proven and legitimate. You ask whether this is Seb's fault: well, potentially yes. If you are lucky enough to be influential as Seb is, then you have a responsbility to be accurate, and that responsibility is directly proportional to the influence you wield. Look, if no one took Seb seriously, then I would not have been bothered with initiating this discussion even if he had claimed he was a bipedal sperm whale. The problem is that Seb IS taken seriously because of his accomplishments.

Anyway, I think I have said all I can in this regard.

On an entirely different matter, I was fascinated (genuinely) by one of the points raised by Eric in one of his posts. He said:

"For example, many types of penguins are born with very low myoglobin levels, similar to that of dry land mammals. However, after only 2-3 years of diving, their myoglobin levels SOAR to > 60mg/g or more. What is this called? A training effect. Why aren't the penguins born with the high myoglobin? Upon measuring the myoglobin of a baby penguin, and finding land-mammal like levels, one might conclude that it is 'impossible' for such a penguin to increase its myoglobin by a factor of three or four by training, but it happens".

I am NOT trying to start another controversy, but I just want to know (because I have not read the actual paper relevant to this) whether the influence of genetics can be excluded here. Training may well initiate the increase in myoglobin (as it can in humans), but the magnitude of that increase is almost certainly dictated by genes. If so, is it not slightly invalid to imply that this large response in penguins is relevant to humans? Human responses are always going to be limited by our genes. This issue may have been addressed in the literature and I would be interested to hear from Eric whether that was so.

I don't consider myself extraordinary or "star" enough to get that much attention. However, considering that the Catalyst segment may have generated some interest I take heed of your advice and will add a message of warning regarding these activities on my website and elsewhere. Though it was already mentioned on the RESERVATION page of the website I have now also attached it to the FREEDIVING page.

Should you find shortcomings with it please point these out as I'm genuinely interested in your expert opinion on such matters of public safety. Thank-you.

My subjective and objective opinion

I came a little late to this thread but anyway I have an opinion.
There is no conclusive studies about the possibility of humans to increase myoglobin, but there is some that give us a clue:

Vogt M, Billeter R, Hoppeler H.Effect of hypoxia on muscular performance capacity: "living low--training high".Ther Umsch. 2003 Jul;60(7):419-24.

Living low and training high, that means to train under hypoxic conditions induces the expressions of glycolitic enzimes, VEGF, HIF-1 system and myoglobin.

Friedmann B, Kinscherf R, Borisch S, Richter G, Bartsch P, Billeter R.Effects of low-resistance/high-repetition strength training in hypoxia on muscle structure and gene expression.Pflugers Arch. 2003 Sep;446(6):742-51. Epub 2003 Jul 12.

They test low-resistance/high repetiition under hypoxia versus normoxia, taking muscle biopsies from only the right vastus lateralis, they found slight elevation of myoglobin levels but with great interindividual variation and no stadistic significance.

MacArthur RA, Weseen GL, Campbell KL.Diving experience and the aerobic dive capacity of muskrats: does training produce a better diver?.J Exp Biol. 2003 Apr;206(Pt 7):1153-61.

In this experiment "divers" rats increased their haematocrit more than "swimmers" rats, but there where no difference in myoglobin.

Masuda K, Okazaki K, Kuno S, Asano K, Shimojo H, Katsuta S.Endurance training under 2500-m hypoxia does not increase myoglobin content in human skeletal muscle.Eur J Appl Physiol. 2001 Sep;85(5):486-90.

In this study there were no difference in myoglobin concentration between hypoxic and normoxic subjects, but initially they were sedentary and the work load of the experiment was low.

Hoppeler H, Vogt M. Muscle tissue adaptations to hypoxia.J Exp Biol. 2001 Sep;204(Pt 18):3133-9.

This wonderful review explains different kinds of adaptation, even at sherpas level. There is a review of the sudies that shown that high intensity training at altitude induce elevations of mRNAs coding for myoglobin and VEGF.

So, there is slight evidence (not conclusive) that humans can increase their myoglobin level. We don´t have any studies from exhalation dives on this issue (a good reason to design one). So nobody has the last word.

My subjective opinion is that it works, I started 3 months ago, and finally have improving in my performances, why?. Let´s study this question.
I think we all know that the main problem with this training is lung squeeze, but with proper safety and slow progress maybe this danger can be subtle.
I havent read all this, I just dont have the patience but from what I have read, it would seem that both sides have some valid argument. Are you two guys in the same neck of the woods? If so why dont you two meet up and work together and make some quantifiable advances in freediving for everybodies mutual benifit.
Or is that just wishfull thinking :)

Thank you for your diplomatic comments. We are from the same neck of the woods, and I have no doubt I will bump into Sebastien one day.

But look, you and others appear to have formed the opinion that I reject exhale free diving and that I sit in an "against" camp, whilst Seb and others sit in the "for" camp. This is not what I have said or meant to say. My concern is about aspects of the way the underlying physiology and evidence in support of this technique have been presented to the wider diving public.

You will have seen my exchange with Ben Gowland above, which demonstrates that some of the physiological explanations of the technique are at least confusing. I am still chewing over my views of Ben's alternative interpretation which does make more sense, but would prefer not to discuss that at this stage.

Franks literature review above (thank you Frank) shows that although claims of being able to induce an increase in myoglobin levels by a training effect are valid, available evidence casts significant doubt on the notion that the MAGNITUDE of that effect will ever be sufficient to compensate for the loss of oxygen storage (42% of total body stores) created by exhalation in humans. Now, maybe that doesn't matter because of savings in oxygen consumption as Seb claims, and maybe the technique therefore works in spite of that, but "increased myoglobin" is often tossed into the justifying arguments for this technique, and serves to reinforce its validity in the minds of divers considering adopting it.

These are just a couple of examples of the presentation and justification of the technique that concern me. I reiterate that it is not the technique itself that is my primary concern, provided people adopt it on the basis of the most accurate information available describing its physiological basis and risks.
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Originally posted by Simon Mitchell

Thank you for your diplomatic comments. We are from the same neck of the woods, and I have no doubt I will bump into Sebastien one day.

But look, you and others appear to have formed the opinion that I reject exhale free diving and that I sit in an "against" camp, whilst Seb and others sit in the "for" camp. This is not what I have said or meant to say.

This is not so!!!!! I suggest you check your earlier kama to see that I privately sided with you on an issue of safety (which is a big issue of mine). My diplomatic comment was mereley a suggestion that a doctor of some repute and a freediver of some repute actually work together an see what actually goes on in the HUMAN body during apnea, this is not only an opportunity for freedivers but for sports science as well. In the world of science, freediving is an infant sport, this is an opportunity for you both to make some real headway for all in this sport. Dont consider this an argument! Consider this an oppertunity not to be missed! BOTH OF YOU!!
I may be a mere Air Hostess but dont take me for an idiot but I do have the best part of a sports science degree and have a static time of near five minutes and never "Samba'd" So make the effort both of you and make progress for us all :D
OK Alison,

You have got me thinking. I have an idea for a relatively "simple" experiment that might just resolve the obvious concerns about inhale vs exhale techniques. I am fairly sure it has not been done before, but I need you guys who watch the literature in this particular field more closely, and who are probably tuned into what others are doing to confirm this for me. However, I do not want to post the idea and method here for various reasons.

If you are interested, I would appreciate hearing from Sebastien, Eric, Tyler and Ben off line at dr.m@xtra.co.nz

If it proves to be a valid idea and we move forward on it, I will keep this list informed.
OK cool, now lets hope someone has the guts to take you up on this :cool: It can only be for the good of this sport :)
What I got of Seb in the sydney papers and on Catalyst program is the understanding they are studying the effects of not only his technique of breath hold but psyiological effect of apnea in general.

I clearly remember the doctor (cant remember his name) stating that science doesnt know what is going to happen and it really is a "frontier" sport. Probably quite unique in this day and age I would say.

I dont think its about having the guts to take up this "offer" but open our minds to the possibilities we really have alot to still learn and bitching and pointing the finger is really counter productive. If it works for Seb, good on him. I certianly dont think he should be burdened with this guilt trip about being irresponsible. Who knows, maybe its just what the sport needs (in this country) to raise its profile.

Finally some light at the end of the tunnel.
I believe that due to the very few people in the world, the study should be a multicenter one.
Let's work together to have valuable data.
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Simon Mitchell,
Thank you for coming to deeper blue and helping to make this into a very informative discussion and mind opening session. I always wanted to know how much the air in the lungs contributed to total O2 body stores.
Best thread in ages

I'm sucking this in like a sponge -- or perhaps more like Sponge Bob.

Best thread I've read on DB in quite some time. Informative and fascinating on a human level too -- seeing guys with a wealth of scientific knowledge start in pissing contest mode and evolve to apparent mutual respect and w/ some altered views. Thanks for the ride!

Looking forward to the paper.

Once upon a time :) the recognised experts said the world was flat and some crazy guy came along and dared to say that it was round and set about proving it. He was right when he said it was round and proven right when the rigours of scientific process were applied. The important thing here is that he was just as right before as he was after the time consuming proving process was completed. (ie the world is and was round!) Go easy on Seb, Tyler and Eric, they just might be right! I humbly suggest that you talk more with Eric as you will find that it has been his life’s work to experiment on himself and others relating to the human potential in apnea and you would be had pressed to find a recognised expert in the diving world who has dedicated more time and brain power than he has to this topic. I think Alison is right on the money with the benefit that could be gained by you collaborating with these guys. The other thing I hope for is that you wont wait until you "bump in to him [Seb]" but instead will seek him out to better understand how he manages to do the amazing dives he does given that they seem to extend beyond the recognised human apnea potential. I for one would like to hear a report from you after you had run him and others through some testing etc

BTW - It's great to have you on this forum as I'm sure you will be a terrific contributor

Salute Simon !

Just wanted to drop in once again and say like others has already said:
-That this thread is maybe the most intresting thread/subject that i have ever read on this forum.
And i also want to say that Mr.Mitchell has proven me wrong , when i earlier related him as arrogant or not being rhetoric enough.
I hope that this will lead to something that will benefit us all in the future.
I also wanna say thanks to all "hardcore-freedivers" that dedicates their lives to their diving , thoose people help guys like me ALOT! im just a "recreational-diver", and i dont have the knowledge or experience to develop my own theories.
I also want to mention something that hasnt been said yet. The most important thing theese days is to give all information you read a critical review.
I feel that it is my own responsibility as grown man to evaluate things.
Diving is SO MUCH about SAFETY and that is needed if you want to spend your time in the water, without big risks.
I would never apply any theories that isnt well proven to my own diving, because as i said earlier i dont have the knowledge or experience to do so.
If im taking my car out on the road i dont drive like an f1-driver either, because i dont have what it takes to do so, and the most important thing i have a responsibility as a driver to drive in a safe way for me and for others.
What im trying to say is that each individual has to take their own responsibility for their own actions !
I dont think that it has been mentioned in this discussion earlier, (maybe because it so obvious) that i cant blame Sebastien or any other diver if im applying his/others techniques to my own diving, and it shows up that it wont work for me.
There so much i free-diving that hasnt been discovered or proven yet , hopefully many questions will get their answers because of the driving forces that means so much for this society.
Until then dive safely and take responsibilty for your own actions and eavulate things before you consider to apply them to yourself.

Greets Jeppe.
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