Quote:
|
Originally Posted by Jason Billows
When you do your sub-neutral breathing do you do any purging before you begin your static? It sounds to me as if you don't. I find that quite interesting seeing as the Dr.s who spoke at the Worlds were saying that Co2 levels were the main limiting factor to static times. They also noted that their studies showed experienced freedivers were doing longer breath holds primarily due to better purging technique, lowering their Co2 levels before a static and therefore allowing more of it to accumulate before getting close to maximum levels during the hold.
|
Purging is just one form of ventilating CO2. Most people use it as a last focused ventilation at the end of more gentle ventilations. The validity of sudden aggressive ventilations is questionable. Since the same ventilation of CO2 can be achieved using rapid light ventilations, or longer gentle ventilations. However, there may be more complex issues at work, such as those explored by Eric Fattah regarding tissue vs blood acidity, etc... I suspect that is where the real differences lie. Back in 2002 the reason I initially tried a static with no warm-up and rapid hyperventilation, was because it occurred to me that the long slow breath-ups were essentially the same thing, just taking longer. All breath-ups are a form of hyperventilating. Play with the variables (time, exertion, relaxation, breath frequency, etc...) and you can probably find that all breath-ups have an equivalent to each other with some combination, in terms of blood acidity (CO2 build-up).
Remember Pete and Eric are referring to a very different warm-up procedure as opposed to a very different breath-up. Therefore they are still ventilating significant amounts of CO2. And if you refer back to the study Jason refers to, then you also find that the study found that freedivers ventilate CO2 more effectively than untrained persons. Which suggests what seems like a breath-up that should not significantly ventilate CO2, could very well be doing that.
So, even though the studies suggest CO2 levels at the end of a breathhold are what bring the breathhold to an end, that does not go against the techniques that are being presented by Pete and Eric, as far as I can tell. However, at the scientific talks I inquired as to whether there had been any studies towards people holding their breath until samba/BO which, in my opinion, would really tell if CO2 was the issue or O2. Actually I am not sure how one could account for people reaching samba, if CO2 was the end factor, unless these are CO2 LMC/BO. However, SaO2 levels tested by some of us, suggest we are hitting O2 LMC/BO. Something which the tests didn't even get close to. I think I remember the doctor stating that it was amazing that SaO2 levels reached lower than 80% in some subjects. Well, that was rather funny to hear, when a few of us regularly play below 50%. Many readings even in the high 20s to 30s for myself, but most likely due to hardware errors at those stages, more likely 40%.
I think it should have been clarified by the doctor, that CO2 was the limiting factor for test subjects that could not hold their breath until LMC/BO. Which is experienced by most of us. So, quite expected.
