The actual impact of Low CO2

[Lauri_A]

Superinteresting stuff, thanks Nathan for pushing the boundaries so that others don't need to!

For narcosis, there's an in-water test that shows the diver a blinking light in the water and when narcosis is increased slowly, at some point the flashing light shows as constant light due to narcosis.

Maybe that could work in a similar way for hypoxia?

 

[Lauri_A]

This was the study, could be interesting to test your own narcosis tolerance as well:

https://www.researchgate.net/public..._dive_Evidence_of_prolonged_nitrogen_narcosis

 

[Nathan Vinski]

Just some updates;

I tired a, not the linked one, colour blind test. Extreme HV did lead to significantly poorer results, evidence of a weaker Bohr effect + cerebral vasoconstriction. I didn't get to test anything during breathholds as I'm training for a deep diving and don't want to mess around with multiple near max statics and tire myself out.

On to deep diving, two days ago I did 55m with two warm ups (2:30 + hangs at 15) and with HV by the time I got to my deep dive I was very alkaline. During the last 10m I felt quite weak and had to do a super slow ascent + squeeze my abs to remain fully conscious. My buddies reported blue lips.

Today I did 60m with one warm up (2:30 to 15). Starting with less alkaline body water due to less overall HV but similar blood alkalinity I felt much better, presuamably because my body water was acidic enough to build back enough blood acidity for the last 15m of the dive.

It seems that my ability to recover Bohr effect depends on the total time I spent breathing (HV) if I'm not doing dives that produce CO2, like shallow hangs.

 

[Lauri_A]

We had a talk with others on hyperventilating before STA & DYN, all shared the same experience that in static it's a big boost but not in dynamic.

Our top guy had tried DNF with 20 breaths opposed to normal 3-4 and it took away 50m from his performance.

One thing was mentioned that fasting makes you more sensitive to hyperventilating, I have similar experiences. So you might want to test that as well?

Have you tried no-warmup in depth? It could give you more dive time...

 

[Nathan Vinski]

Have you tried no-warmup in depth? It could give you more dive time...

With FRC no-warmup worked very well. I wasn't confident passing 45m with warmups but 48 on dive was was super easy. Equalisation became a problme however, because of urge to breathe w/out warm ups.. On inhale I feel like i would squeeze without a good warm up dive. I dabbled with riding the bottom weights to 45 as a warm up but even that was a little tight, but 1 hang at 15 gets rid of the tightness on deep dives.

 

[J Campbell]

When I was younger and skinny and did deep rapid hyperventilation I got rather dramatic effects - the finger tingling, dizziness, and almost pass out at the beginning of a breath hold, followed by a period of blissful well being. Now I'm older, 30 lbs heavier aand I can HV to high heaven and only feel mild effects. Is there a correlation between age/weight and CO2? Or is my case just happening to me? What changed in me?

 

[Nathan Vinski]

When I was younger and skinny and did deep rapid hyperventilation I got rather dramatic effects - the finger tingling, dizziness, and almost pass out at the beginning of a breath hold, followed by a period of blissful well being. Now I'm older, 30 lbs heavier aand I can HV to high heaven and only feel mild effects. Is there a correlation between age/weight and CO2? Or is my case just happening to me? What changed in me?

According to research on CO2 buffering, Eric's CO2 compartmentalization thread (linked in here), and some of my own little tests then I wouldn't say that it has anything to do with age, but with body weight, and maybe improved freediving fitness.

The majority of the bodies CO2 is actually stored in the body water, the more mass you have, muscles to a certain degree and fat to a massive degree, the more water you have to store it. More mass will also increase you total blood volume which makes a small difference too. This will increase your total CO2 storage and it will take longer and more aggressive hyperventilation for it to change. compared to skinny you (same lung volume -> less CO2), where each breath cycles a larger %% of total CO2.

Improved physical tolerance to CO2 from many years of training might have increased your levels of blood buffers. Even small increases in blood buffers means that PH levels will change at a much slower rate due to higher CO2 storage capacity. This means longer time to contractions during a hold, and also longer time to feeling the effect of HV, as the total blood CO2 will be higher and more breaths are required to blow off a significant %% of CO2.

My whole theory about why HV doesn't seem to negatively affect me is that I have naturally low Blood buffers, part of the evidence for this, other than early contractions even after good training periods, is that it only takes 8-10 deep inhales over 15-20 seconds to feel a tingly face. I can use alkalinity to store more O2 in the veins, but the acidity comes back fast enough to get the Bohr effect back. What I found out a few days ago was that blood buffers and body water are completely separated. If I do 1 too many HVed hangs that don't produce CO2 and my body water becomes overly alkaline my blood won't re-acidify enough, and some O2 gets trapped in a closed cycle.

The point of this being that even small changes in where you are holding CO2, how much body water you have, how much blood buffers you have, and how much CO2 you produce on a dive changes things a lot. So for me its one extra hang, and for you its 30 pounds, but both of those types of things make a huge difference in how breathing and not breathing can affect body PH and its symptoms.

 

[Lauri_A]

If CO2 is stored in the body water, then that makes sense for the diet comments. Fasting drains the glycogene levels which stores more water in the muscles.

Each gram of glycogen is taking around 3-4 grams of water with it, so if you load an extra 1kg of glycogen you gain 3-4kg of water with it. Likewise if you fast and loose the 1kg of glycogene you also loose 3-4kg of water.

 

[Chad StClair]

Just a dumb question but if you hyperventilate dry and do statics full lung I push my contractions out from 1:20 till about 3 min and empty from :15 till about 1 min on fist breath hold of either. But there is something in my brain that says now is your normal contractions time and I get a bit of a ticke in my throat but it passes and I continue the hold happy and almost giggly... If you do HV dry holds will it shift your contraction point because your brain will have a new “contraction time” where you get so used to the late contractions your body will shift to later on normal breath up dives??? Just curious if anyone has experimented with that?? I am going to try for a month doing HV dry holds full and empty to see if it does anything...

Chad

 

[Nathan Vinski]

I used to struggle with having contractions at depth and the way I trained this was with hyperventilated RV statics to get used to having "empty" or low volume lungs, as I would at depth. After a few winter month of doing this I pretty much stopped having contractions at depth.

The reason for this is that contractions come from 2 different sources; either CO2, or muscular tension. To work on the tension bit, you must isolate it from CO2 (with HV).

So yeah, I think that it is a valid way of training your mind and body to stay comfortable for longer. Personally, since I started diving (not just training) with HV I've actually gotten less and less contractions no matter what breath up I do.. Sometimes I do demo-statics 2-3:00 when Im teaching (can't HV in front of students) and despite not doing any C02 training I don't get even the slightest urge to breath at that time.. Previously, in my best condition, my static contractions would come at 2:00 the latest.

 

[Marciano]

it took a while to find because if forgot the title but lots of good information in this thread..

https://forums.deeperblue.com/threads/co2-compartment-hypothesis.41696/

My thoughts on how it applies to me are that my natural CO2 buffering is bad. When my training was going well the latest I could ever push my contractions with normal breathing was 1:45. 4:45 was really fun :/ On days where I was even slightly unrelaxed or hadn't been training properly that went down to around 1:20. Other Eric Fattah experiments that I tried (eat/drink baking soda) did help a little bit, but also made me feel quite sick after so I couldn't use that.

Reasons for this are most likely genetic and partly diet, I eat a lot of meat and carbohydrates, and probably too much cake. basically I don't eat a lot of bi-carbonate (buffer) forming foods. And considering that it only takes around 15 forced+full inhales + passive exhales for me to get severe symptoms of hypocapnia (further evidence of low buffers) and even on statics starting on the edge of HV BO I still get contractions before 5:00 I must be building enough acid to negate the negatives of high alkalinity.

Attached is another Eric Hypothesis.. hadn't read that before but the thought process supports my thinking that using alkaline blood to our advantage to oxygenate the veins and limit O2 desaturation at the beginning of the dive might help as long as we build back acidity to use the O2 near the end.. Since my body seems to build acidity quite quickly, this doesn't cause any issues for me.

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I suffer from the same evil, urge to breath is simply wild, the word contractions can be replaced by convulsions in my case. No amount of relaxation, or stress makes a significant difference.

After advice from Branko Petrovic, current WR in static, I added a little bit of hyperventialton, I went from 5 min. no HV to 7:00 min. no signs of hypoxia. With further tests (O2 and HR) it was clear that the huge contractions where increasing the heart rate (it was necessary a good heart rate to catch those spikes). Also better recovery rate.

My theory is that certain individuals are more prone towards contractions, and even in a relaxed state, the muscle convulsion created by contractions, increase O2 consumption and chest pressure to a non beneficial level.

I do think, that years of high carbohydrate + plus sugar diet, lead to this situation (I am currently switching to ketogenic diet for at least 4 months as an experiment).

 

[Nathan Vinski]

I suffer from the same evil, urge to breath is simply wild, the word contractions can be replaced by convulsions in my case. No amount of relaxation, or stress makes a significant difference.

After advice from Branko Petrovic, current WR in static, I added a little bit of hyperventialton, I went from 5 min. no HV to 7:00 min. no signs of hypoxia. With further tests (O2 and HR) it was clear that the huge contractions where increasing the heart rate (it was necessary a good heart rate to catch those spikes). Also better recovery rate.

My theory is that certain individuals are more prone towards contractions, and even in a relaxed state, the muscle convulsion created by contractions, increase O2 consumption and chest pressure to a non beneficial level.

I do think, that years of high carbohydrate + plus sugar diet, lead to this situation (I am currently switching to ketogenic diet for at least 4 months as an experiment).

You basically summed up my theory on the whole thing.. Thanks LOL.

I have tried eating Keto one before, and i think I've mentioned this somewhere in much older thread.. It works very-well for serial diving, but muscle failure becomes a serious issue when doing 1-off max dives (not static). The reason is quite clear if you understand how ketones produce energy.. They need O2 and are very inefficient in near-anaerobic states (what you get with blood-shifted legs). Interestingly I've been eating a much more carb-rich diet since I started the thread, and I've been feeling much more 'energetic' towards the end of the dives. of course that could just be the training effect.. and I'm now I'm a better/stronger diver..

 

[Marciano]

@Nathan Vinski , do you also include low water consumpton + lots of coffee in your diet?
I am trying to search for patterns here.

 

[Nathan Vinski]

@Nathan Vinski , do you also include low water consumpton + lots of coffee in your diet?
I am trying to search for patterns here.

No. I (especially before diving) hydrate a lot.

I'll only have 1 coffee per day, sometimes 2 if i do a big workout. I use the caffein as a way to boots glycogen regeneration to help prevent muscle soreness and tightness