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CO2 tolerance training idea

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Well-Known Member
Jan 21, 2003
I thought this up as an alternative to C02 tables that should capture at least some of the benefits without so much time or discomfort. Does the following make any sense??

I think you can regulate your co2 saturation at whatever level you want by taking very shallow intermittant breaths. The idea is to breath enough O2 to continue but not breath enough to decrease the co2 level temporarily. I measure this by the pattern of contractions. As long as the contraction rate and strength as well as discomfort level are constant, I'm assuming co2 level is relatively stable.

As an example: exhale to relaxation (FRC) wait for contractions to begin and then breath (in then out) very shallow, one breath every 10 contractions. For me this breathing rate keeps my "apparent" co2 level constant and I can continue longer than I have tried so far. With a little experimentation, it ought to be possible to measure progress on co2 tolerance.

If this works well, it has the advantage of requireing less time and attentiion than tables as well a less discomfort.

This technique produces a steady moderatly high co2 level. Tables provide a rising but highly variable co2 level with high peaks. Can either one work as well?? What do you physiology experts think?


This is similar to the CO2 table I have been using for years, namely, one breath, hold for X contractions, one exhale, one inhale, hold for X contractions, etc.... Eventually you will start getting contractions within 10 seconds of the inhale, so there is no wasted time 'waiting' for contractions.
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Nice idea.....

Eric, I'm assuming you have tried this hooked up to an oximeter? What O2 saturation do you maintain and is it high enough to know that the contractions are all from high CO2 only?


Sounds good...

Would this work if I measure a fixed time, say 30 seconds, from the time I start feeling the urge to breathe, as I don't normally get contractions?

Hi Lucia,

I was trying to achieve a relatively high constant co2 saturation. My measurement was contractions and discomfort level because those are easy for me to measure. Whatever measure is best for you should work.

I tried it and it worked - maybe I'll do this instead of CO2 tables sometimes, as it is easier and needs less concentration.

Great idea connor!
However your technique looks similar to exale static, exaling to FRC, while eric's technique looks like inhale static with only one breath between holds. i find the first option more difficult and i believe it works as o2 and co2 table at the same time.
Anyway, thanks for great exercises!

Another idea for CO2 tolerance - statics with no preparation. I have tried this, and it is difficult, but it might be good for training in a short amount of time without getting too tired.

Co2 and o2 tables at the same time? umm. More than I intended, but I see what you mean. You could do my idea either inhale or exhale. FRC is just quicker and, for me, more relaxed. Constant co2 level for a long time while maintaining enough o2 to stay alert was my object. That brings me to recasting ADRs question of o2 saturation, it is one of mine also. Does this technique maintain enough o2 saturation to do while, for example, driving a car?


A CO2 training technique that seems to minimize the "discomfort" for you may not be accomplishing as much CO2 tolerance training. That's kind of the point of CO2 tolerance training, to learn to handle the discomfort.

I do two types of CO2 tolerance training. Type one I call "slow burn." That's where you maintain a certain threshold level of CO2 build up for extended periods, but you don't push it to your max tolerance. For example, sometimes I will swim a thousand yards continuous, breathing twice a length. The goal is to stay hypercapnic for long periods. It never gets too uncomfortable. Your exercise seems to me to fall into this category. Type two, the goal is to reach as high a level of CO2 as you can tolerate. So, instead of counting contractions, and breathing every 10 contractions or so, you go for as many contractions as possible before blowing off any CO2. This is the more uncomfortable of the two types. In my opinion, you cannot avoid the discomfort.

"Does this technique maintain enough o2 saturation to do while, for example, driving a car?"

Yikes. I'd only feel comfortable saying "yes" if I can be sure people doing this aren't driving in the same city as I am (or anyone I care for). Though not a high risk, there's always some risk of low O2 causing an unexpected loss of motor control or (heaven forbid) a blackout. Why risk it while driving a motor vehicle on public roadways? Years ago I sometimes held my breath while we went through tunnels in the car, usually less than a minute in duration, sometimes a bit longer for those super-tunnels. However, I quickly realized that there was too much at risk to do so if I was the driver, not merely a passenger. So, I stopped doing that because I decided that the safety of my passengers and other people on the road was more important that getting in the "free" apnea-training time. Life is precious....
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i am doing this now going for as long as i can between breaths. i love the feeling of hypercapnia it is great. i get contractions almost instantly. this is completely and totally awesome guys!
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