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CO2 compartment hypothesis

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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Thanks. Everything is clearer now. That vagus nerve stimulation opens up a whole new area to think about. I have heard that vagus nerve stimulation through electronic box implants is something that has been researched to help people with chronic depression and other mental disorders. Maybe this is why us freedivers, with stimulated vagus nerves through high CO2, are so mentally stable.:D

So I take it, when one is doing hyperventilating, they should do them with as little strain as possible.

If you have Peter Lindholm e-mail address, would you PM me it?

John Aderson, a 5:40 breathold without any training, is pretty impressive. I started way lower than that. I think you would get better “non technical” responses to your questions in the “Beginning Freediver” forum area. This thread is a pretty technical one about Eric Fattah’s CO2 body water / blood hypothesis.
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This is a mighty interesting thread. I'm just not quite shure I have it understood properly. As I understand it so far:
alkaline blood is good for statics; but then tylerz says lemon juice is not your friend cause it makes the blood more alkaline; but if this is true of fresh lemon juice only then old lemon juice is your friend?; also, i have a friend on the Finish freediving team who once told me they take bicarbonate of soda/baking powder for statics, isnt this an alkali?
Could someone explain it for me once and for all please if I should try fresh lemon juice or old lemon juice or bicarb or none of these?
and is all this talk about statics only and not constant weight diving? efattah said acidic blood was good for his diving but sucked for statics. should we be making clear the difference between the two. thank you
Taking sodium bicarbonate (baking soda) in water, is the ultimate most brutal and rapid way to make your body alkaline. However, if you take more than a gram or so, you will probably be running to the bathroom in agony. I have tried it, and it delays the contractions dramatically--however, being too alkaline is no good either.

BTW this is my 900th post!

Eric Fattah
BC, Canada
Congrats on the 900 posts, I'm looking forward to your next 100 getting you to the big 1000. I think at 1000 DB should put you on a "DB hall of fame" list.

Health & Acidity of Food

At work the other day we had a guy come in to do one of his regualr sessions on health and he had the following to say on food consumption and the acidity of different foods.

"The following table indicates which foods have an alkalizing effect on your body and which foods have an acidifying effect on the body. For good health, try to eat 80% of your food from the alkalysing list and 20% from the acidifying list.

Don’t allow yourself to become obsessed. Try, 90% of the time, to eat for health by eating from the foods on the left. A few slip ups will then be of little consequence. Also remember to supplement your eating with things that are extremely alkalysing like Celtic Sea Salt, Colloidal Minerals, Barley Grass Powder, Chlorophyll, Seaweed products like Wakame and alkaline waters.

Start the day with a glass of warm water with the juice of a lemon in it. This stimulates the pancreas to release bi carbonates into the blood, thus having a powerful alkalysing effect."

Here is the table: .....hope this works


  • food.doc
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Eric, In your reply to Don you state that an ideal breathup would be close to no breathup at all, that high CO2 levels result in higher O2 levels at the later stages of the breathhold. For statics this approach only works if you have enough CO2 tolerence to fight the discomfort.
But what for CW? Is there such a thing as not breathing up enough? I'm trying to answer this through my diving and it doesnt seem to me like there is. I remember you once mentioning a '12 contraction rule' or something to that effect, stating that this would be roughly the amount of contractions you would want to have before surfacing. Do you still stand by this?
My diving experiments are limited by the depth of the dam to statics of increasing length at 45m, so I dont really have the issue of CO2 toxicity to worry about at the moment(or do I?), but my concern is when I get the chance to dive deep water: does and extremely gentle breathup pose a risk at depths approaching 80M? I would be very grateful if you or anyone else could get this worry out the back of my mind. Thanks
Originally posted by donmoore
"If memory serves (which it may not ) then it takes 5-10 minutes for a red blood cell to make a return trip from the lungs to the legs and back when at rest"

Ben, and everyone lots of good thoughts, but I think this incorrect. It takes 11 seconds for hemoglobin to transfer O2 from the start of my breathing, after a hold, to reach my index finger, where my pulse/oxymeter reads it.

My memory tells me of *about* a 1 minute (after a calculation of heartrate*heart volume) for a full cycle - from my freediving course, though it was used as an exapmle for something else so maybe not be exact.

However, the 11 seconds resualt on your oxymeter may be explained due to some other reasons. (I'm just speculating, I have no idea of how the oxymeter gets it's reading, but maybe the manufacturer can answer that.)

When you stop your breathhold, there's a sudden change in heartrate and blood pressure (all the blood stored in your lung's blood vessels, the fresh o2 etc.), that may (or may not, I don't know how these gadgets work) cause the change in reading eventhough the "fresh" o2 did'nt arrive there yet. Just speculating. This should be approved or disapproved easly I guess.

By the way, this thread is fascinating! thanks Eric (and the rest)!.
Originally posted by efattah
Just a few more results like Alan's, and the 'hypothesis' can be upgraded to a 'theory.'

Eric Fattah
BC, Canada

I'm a freedive trainer.
Last night I suggested to two friends of mine the following training table:

3min breath 3:0:6:0 no pack
2 min hold
8min slow deep breathing no pack
2:30 min hold
4min breath 3:0:6:0 no pack
max static

Both of them obtained their PB!!

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Paloino, Di they pack for their max static?

As far as time for it takes to complete a full cycle, my buddies and I always use 5 minutes as a cycle time in tec diving when doing our gas switches. That means when we come up to a stop where we switch to a new deco bottle our stop is at least 5 minutes to get full effect. Not sure if it completely transfers over to freediving.

I've found this thread usefull because I've been trying to experiment a bit with pH levels in my diving. I havent tried the four breathups as Eric outlined in the begining of the thread because I'm a bit nervous to trying such radical departures from my normal breatup, and also because I wanted to arrive at 'maximum depth' with my current breathup that I could then use as a yardstick against which to measure the other types of breathups. I think I found that 'maximum depth' using what I guess to be a pretty acidic approach:

3 statics with shortish intervals between them and no breathup, to 100,150&200 contractions(but none going much over 3:00)
then 3 empty lung dives to 6,8,10m
then 1 slow pulldown to 45m
then 1 static to 50 contractions
1 empty lung to 10m
then a six minute breathup: 5:2:10 with the last four breaths being 4:20:10 then pack 17 times (no purges at all)
Also, the night before I had steak for supper and biltong at midnight. Forgot the orange juice I had planed to have before the dive.

The dive was a cnf to 45m. Interestingly, though kind of what I was expecting, the contractions started the second I reached the bottom. Fairly smooth, about 4 seconds apart at first. I did a 50 second static during which I lost count of them, but remember them being quite strong on the ascent. Surfaced clean but just bairly.
I'm feeling somehow that diving with this much CO2 works for me. Which is why I'm wondering if Eric still thinks 12 contractions to roughly optimal. I must have had over 50. What I want to do now is include a few purges into the same warmup & breathup routine and see what happens. Will try this in 2 weeks and post what happens. I predict a b/o but hope I'm wrong.
Into which of Erics four blood/water catagories do you thing my warmup/breathup puts me?
a different method

I would be surprised if we can't make improvements in static performance by manipulating the pH of various tissues. However I would also be surprised if these improvements were very significant.
Umberto never stops saying that static is 90% in the mind, and with that in mind I created a static table designed to facilitate a maximum performance by inducing a positive psychology.

1). Warmup (short CO2 table / pranayama)
2). Breathe up
3). 'Contraction Static' (try to delay the first contraction as much as possible. Remember the time of the first contraction. Continue for 10 contractions (or a number that is roughly 1/4 of the maximum amount of contractions you can endure). Try to space out the contractions as much as possible. Remember the time at the 10th contraction.
4). Breathe up 4 minutes or for the same duration as last apnea
5). Repeat (3) & (4) two more times. Do not exceed the established number of contractions, but rather attempt to delay them and spread them out more than in the previous apneas.
6). Max attempt as normal.

If you set yourself a goal of time for warmups then you will worry about whether it is too much or too little, and you will not reach the right frame of mind. However the three 'Contraction statics,' despite being excellent warmups, aren't the least bit psychologically demanding, as you know that you only have to endure 10 contractions. By the time you come to the maximum attempt you will actually be eager to push past the set number of contractions. This positive attitude is the key. Try it next time you do a regular session.
Didn't work for me - sorry Eric! !

After the great result that AlanC got from trying this I thought I should try something pretty much identical to what he did and see where it took me. With a PB of 5:04 I was hoping for a little more and a new PB but ended up with a lot less. Here is the detail.

1/4 teaspoon Bicarb in glass of water 20mins before start

2 min slow deep breathing (3 breaths per minute)
1:40 hold
2min slow deep breathing (3 breaths per minute)
2:30 hold
8min slow deep breathing (3 breaths per minute)
1min hyperventilating
3min C02 table (1min hold - 1 breath - 1min hold - 1 breath - 1min hold)
2min hyperventilation
inhale + pack - 4:02 hold.

50 contractions starting rather early at 2:45 and they were not much fun right from the start and were hard and fast towards the end.

Perhaps I did something wrong that someone can point out......Eric, any ideas?


I use the same method that you describe to get the right psycologic approach.

Before I started using this method I was very up and down in my performances and my average result was around 5'15''. After I started using this approach I have calculated that my average is 5'42'' with a pb of 6'08'' and the lowest time 5'27''.

My 'slow deep breathing' was nothing like yours infact i shouldn't really have called it slow at all i was using 2-0-8-0 in-hold-out-hold.

Now i've had a few more sessions i'm thinking the CO2 table is un-necessary, cos all that is doing is acidifying the blood which you then alkaline again with the hyperventilation. The thing that made the difference is the 'deep breathing' for long enough to alkaline the body water. For instance last night i did 5mins deep breathing and did a 4:00min first hold and then 5mins of deep breathing and an easy 5min hold. This is going back to what has been discussed about the best breath-up being no breath-up, the only differnce between the first and second hold was i was able to delay contractions for that much longer.
thinking the CO2 table is un-necessary, cos all that is doing is acidifying the blood which you then alkaline again with the hyperventilation. The thing that made the difference is the 'deep breathing' for long enough to alkaline the body water.
Ditto - my thoughts too!
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..the possible way is acidic diet , 'deep breathing' for long enough to alkaline the body water and no hyperventilation


It could be that one can overdo the studying, analyzing, experimenting, practicing, etc.

Personally, I've noted that lack of interest in the outcome has often led to surprisingly good results, at least in my case.

My PB of 6:22 ( and I'm old, quite decrepit, do not train, and don't like doing static apnea) happened one day at 7 AM, an unspeakably barabaric hour at which to be out of one's bed. I was there only because I was obliged to be, and was sufficiently miserable as to have become completely indifferent to everything. I experienced no discomfort or struggle.

Maybe this is some sort of Zen-like thing going here ? I'm not sure whether I have any advice on inducing it. The only method I know of is to become an bitter, misanthropic, anitpathic, middle-aged fart like me. Global nuclear war tomorrow, you say ? Pass the nuts please, say I.....

Serenity now.....serenity now.......

Paul Kotik
Florida, USA
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Hi Everyone,

Just to let you know, Eric is having a hard time typing these days--a bad case of carpal tunnel or tendonitis. He's down to typing with his nose, if you know what I mean. Hopefully, he'll be better soon.

I agree with you, Paul. That is the reason why I often seem to do my best in all events during competitions. That feeling of no turning back, time speeds up, and three minutes of contractions doesn't seem so bad after all. And I yell at myself if any thoughts of pulling up early start buzzing around.

As you may have seen on the Beyond 6:30 in Static Apnea thread (http://forums.deeperblue.net/showthread.php?threadid=38733&perpage=15&pagenumber=2), I have had lots of success on the first static. In the last four sessions, I've done 5'00", 5'48", 6'11", 5'38" on the very first static of the day (all statics are wet). My new pb is 6'26" and that was on the second static (after the 6'11"), after resting for five minutes and breathing up for five or six more. This is a new pattern and it's working well for me, although I have started doing more than two max breath holds in the hope of gathering more data on the effectiveness of the breathe-up, required intervals for recovery, etc... (see the later postings).

My point is it's hard to tell from so little data whether the CO2 comparment ideas hold true: we need lots more data. And I would hesitate to make hasty comparisons between each other. Especially for those of us who have not really done regular wet statics over a long period of time. So I don't think that after one try with a new breathing pattern you can tell if it works or not. It may just be more psychologically difficult...until you get used to it.

Vancouver, BC