Amount of air in holds

[Chimo]

Ok, this question probably derives from my lack of knowledge but.. I wonder bout practising breatholds (tables etc) and the amount of air in the lungs. Escpecially when it comes to CO2 tolerance. Wouldnt it be more time effective to exhale and do holds on empty lungs? whereby the contractions comes soo much faster. Or does the body somehow need to adapt to having the air in your lungs. I assume for example that when doing 02 tables that the body somehow adapts and improves its handling of the oxygen in the lungs, plus the force needed to maintain the air in the lungs needs to be practised. I wonder if this makes sense. If I put it like this:
Why is it not good to practise static or dry apnea on empty lungs?

Any answer is greatly appreciated!

 

[DiverTodd]

Hmm, an interesting question. From what I can gather, I think your body needs to learn to adjust to the gradual "change over" from O2 to CO2 (or, the decreasing O2 and the increasing CO2). This is better accomplished, of course, with lungs full of air to use. When you start with empty lungs, there's not much there to convert in the first place.

Todd

 

[trux]

This comes actually back to the question of Lucia (aka Naiad) in the thread CO2 tolerance. On my mind the CO2 tolerance is primarily psychological - getting used to it, and only in a lesser way there may be some physiological change of the organism being able to handle the higher CO2 levels (if there is any at all). In this way doing the full lungs long tables with longer apneas and also longer suffering under CO2 contractions may be psychologically better to get resistant against it. However, the empty lungs apneas, although shorter, are often more intensive, so it is a real question what makes more impact on you - the time or the intensity? Maybe you'll need to find yourself what's working best with you. It may be a combination of both methods. Definitely, when you have little time, it is easier to make empty lungs CO2 tables then the full ones, so once you achieve certain level, you'll have to switch to empty (or semi-empty) lungs tables anyway to save some time (unless you are a full-time pro freediver)

 

[Mullins]

Empty lung statics only last a couple of minutes or so; you won't be producing much CO2 in that time. They only reason they're more 'intense' is that you're lower on O2.

 

[Will]

Although you produce less CO2 there is less room in the lungs for the CO2 to off-gas, so the effect is similar. I only ever train empty-lungs, as it is more specific to constant weight and a more efficient use of training time.

 

[Mullins]

If blood CO2 increases similarly, wouldn't you expext big contractions on an exhale static, as with on inhale? I find there is no real urge to breath right up to the point of samba, bar that hypoxic 'weak, painful' feeling through my torso & legs. I get huge contractions on inhale (somebody charmingly described me as looking like a "mating crocodile" the other night)

 

[trux]

I do get strong contractions on exhale CO2 tables. Maybe you hyperventilate too much. Do not forget that the purpose of a CO2 table (regardless if with full or empty lungs) is to reach high level of CO2 in lungs, so intensive ventilating during the breath-up is counterproductive and may indeed just lead to hypoxia instead of hypercapnia.

 

[Mullins]

Yeah, I do a pretty minimal breathup - more aggressive breathing doesn't seem to change the subjective experience of exhales anyway. Although I haven't actually tried doing a CO2 table with exhales, that might result in some contractions... (I just do one-offs as warmups). It could also just be the fact that the diaphragm is in a different position and doesn't tend to spasm as early, might be something that differs between individuals.

Back to the original question - wouldn't you be dicing with hypoxia a little by doing tables on exhale? I'm sure you could get them to work, but you'd need to calibrate them fairly well to keep CO2 levels high and avoid getting low on O2. With inhale statics it's very easy to get huge CO2 levels without having to worry about a blackout.