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Get high and get on down: a response

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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sebastien murat

Well-Known Member
May 18, 2004
Dear all,

For those contemplating purchasing such things as hypoxicators and altitude tents to boost their haematocrit (Hct) there is a much simpler and cost-effective solution:

Breath-holds (dry) on 'empty' lungs after prior hyperventilation will give you even more pronounced effects (I say dry because hyperventilating prior to holding the breath in water can obviously lead to drowning). In my case, for example, Hct is 63%, which is way beyond anything that has even remotely been achieved with these devices evn after continous use. Moreover, such breath-holds permit one to reach lower O2 saturations and more frequently, which is an important factor in the magnitude of the adaptive response.

Such a simple technique is not only easy and cheap to effect as it requires no time and no cost at all but is in itself applicable to employment by a variety of athletes involved in endurance activities.

Hi Sebastian,

How much time before a breath hold performance should this be implemented to get the maximum desired result? Also, how long is it effective for afterwards?


ps. Congratulations on the impending arrival!

Thanks, maybe he/she will decide to become a little diver.

I'm not sure what you mean, but if you are reffering to lead-up time, then the sooner the better. On the other hand, if you're talking about the last training session before a comp, then, I would say, in my opinion, no more than one day's rest.

The more frequent your training sessions the more long-lasting the effects. the more intense, provided that one obtains adequate rest, the greater the effect.

One should expect to see changes in Hct in less than one month.
hi sebastien, i have a few questions:

first of all, are you talking full hyperventilation, or moderate hyperventilation?
and also, how long should the holds be, in terms of difficulty.......i am not sure if it would be best to do 90% holds or 100%, and also the length in between holds?

Another question i have is although i read the article, i did not understand fully what the training will do. Will it just increase my low o2 tolerance?

thanks for your time,
rory west
The reason I suggested hyperventilation is because probably few amongst us have the drive to do max breath-holds without hyperventilation. It simply makes it easier. However, for those with a willfull will and who can push it without hyperventilation greater rewards would be achieved by not blowing off CO2 as that promotes even greater O2 desaturation and in my experience a better tolerance to low oxygen pressures (PaO2). PaO2 is the important factor has this is what keeps you conscious not SaO2; although both are intimately related.

The aim of "living high-training low" is to stimulate red blood cell production. This in iteslf increases the body's, i.e., blood, O2 carrying-capacity and CO2 buffering ability, both of which will prolong absolute breath-hold duration and possibly (?), hypoxic/hypercapnic tolerance.

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hi! sebastian, can i ask what the 63% means? i've taken blood exams for work and almost was not hired because of high hematocrit levels (or was it rbc count). the doctor advised me just to drink lots of water but i resorted to donating 2 liters of blood just to get it down to an "acceptable level". they said that it was bad because it means that the blood is thick. but isn't the viscosity and hematocrit/rbc different things?

Sebastien, do you have any suggestion to what kind of series would one want to do to get a good response? Would one want to get to LMC or close to it on each hold?

How does something like doing daily 5 times "max" exhale breath-hold with rest intervals which are about equal to the breath-hold sound (just off the top of my head)? Or would it be more beneficial to do more repetitions at say 80% of your max?
If you don't want to hyperventilate I have found I tolerate empty lung statics better in a seated (e.g. 'half lotus') position, where they can also be combined with pressure adaptation /compensation manoeuvre exercises:
  • apnea after full exhale + held diaphragmatic introflexion ('uddiyana bandha' in sanskrit)
  • apnea after full exhale + 10-20 reverse packs
These both train diaphragmatic flexibility and ribcage elasticity and will therefore make hydrostatic pressures more tolerable. The latter also trains the 'mouthfill' manoeuvre, vital for compensation in FRC or extreme inhale diving.
I would suggest 3 of each in that sequence, with 2 - 3 minute recoveries. I don't know about going to LMC, not because of danger (there isn't any in DRY statics) but because I have a hunch that the body 'learns' to LMC, and there is a greater tendency to do so thereafter.

As a sidenote yogis insist that apneas are performed in a seated position, so as to enable access to the 3 locks (bandhas) and channeling of kundalini energy from the coccyx. They also advocate bhastrika (an agressive form of hyperventilation) before long pranayama holds. Also if you want to master the 'breathless state' you need to cut the frenulum on your tongue so that you can force it back down your throat to stop contractions...

Carlo, haematocrit will increase blood viscosity, but if the rise in hct is natural (autostimulated) then the organism has countermeasures to balance viscosity. For example I have experienced a huge drop in platelets, which are responsible for blood clotting and thus thicken the blood. Viscosity agents are also released, but you will have to wait for Seb to explain those.
Hi Sebastian,

Yep that was exactly what I was referring to, thanks for clearing it up.

I continue to find it amazing what you guys can do with your advanced breathing techniques. Sebastian is right when he says it is possible to increase your Haematrocrit levels with breath hold exercises. The human body is the most adaptive species and usually finds ways to cope with the different stresses you choose to put upon it.

The Hypoxicator is just a tool that makes this process a lot more comfortable. By eliminating the CO2 build up associated with breath holds, you are able to simulate the same low oxygen level, without triggering the urge to breathe. A session on the hypoxicator is a pleasurable experience that produces strong physiological adaptations -this might be too soft for hard case freedivers who enjoy the pain.
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Question for the altitude training center. Is there a greater risk of cognitive impairment from the IHT regime? The accepted theory among freedivers is that temporary hypoxic states do not result in brain damage. But, I wonder if greater risk of brain damage results from prolonged hypoxic states, which, if I understand the training technology you utilize, form the basis of IHT. I mean is one hour in a state of hypoxia safe?
Chronic or long term Hypoxia is bad for you and can be responsible for illness and disease. Bad breathing can create chronic hypoxia that goes unnoticed and wrecks slowly. Acute (short term) Hypoxia that you practice in breath holds and with Intermittent Hypoxic Training, puts the body under hypoxic stress for a relatively short period of time (Intermittent = 5 Hypoxic air, 5 minutes ambient air) and produces a training effect that enables the body to deal with oxygen more efficiently. So when you are not practicing breath holds or IHT you have an enhanced oxygen transport and utilization system which prevents chronic hypoxia from occuring. Research has shown that training with Hypoxia produces no significant impacts on simple and complex opto-motor coordination during short-term breathing with 10% oxygen. Similarly, during long term elevations above 5350m of more than 15 days, the response to a memory task was significantly enhanced.
Michael said:
The accepted theory among freedivers is that temporary hypoxic states do not result in brain damage.

Maybe there is a bit of circular reasoning here . . .a number of friends tell me that a bit of "brain damage" is necessary for a person to want to dive 30 meters or more underwater on a breath of air. :duh

I believe it was the eminant philosopher James W. Buffett who wrote: "If we weren't all crazy, we would go insane."
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This thread was too much for me and although I probably agree with Seb I couldn't resist building a hypoxicator this weekend. Here are some pics in all it's glory. I included a sensor to monitor the O2 content and used my pulse oximeter to moniter SaO2 for the first trial.

Now all I need is some advice for an IHT program.




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Personally I don't think a hypoxicator is useful for a freediver. For example, with an oximeter I was able to create exactly the same graph of SaO2 as is shown in the hypoxicator studies, except I could plateau as low as 55% if I wanted to, during the hypoxic phase. The method was simple, hypeventilate, exhale, hold for N seconds, then pack Z times every M seconds. I asked Oleg at Go-2-Altitude why I should buy a hypoxicator if I could achieve the same SaO2 cycle PAINLESSLY without any machine. He admitted it wasn't useful for someone with that level of breath control.
I probably should have explained how it works. The mouthpiece is a standard snorkel mouthpiece connected to a plumbing 90 degree bend (this has two one way flapper valves inside it). THe exhaled breathe heads down into the wine cask bladder. On inhale the air heads out of the bladder and over to the CO2 scrubber(soda lime). THe pipe goes all the way to the bottom of the soda lime and the air travels up through the soda lime and then out through the second pipe back to the mouth piece. the sensor is right next to the pipe heading back for the inhale. In addition there is an extra pipe which also goes to the bottom of the soda lime and has a valve on it outside of the container (this valve allows me to vary the amount of fresh air that is mixed with the system allowing me to maintain a constant O2 % in the system. THe voltmeter reads from the sensor (5.5 mV relates to just over 10%.)


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Hey Andy - did your wife get angry when you drank all the wine then pulled the vacuum cleaner apart? :D

I just tried some exhale holds. I got to 10 - 30 seconds with a couple of holds without hyperventilation before the intense urge to breath got the better of me. After a minute of hyperventilation though my holds extended to 1:30 and 1:40, with a comfortable period of about 1:10 each time. And I was able to expend more air each time. I was very surprised the comfortable period lasted this long.

This is interesting, i'd like to see how this translates to actual results in a couple of weeks time.

ADR... this looks like a reabreather to me!!! are you shifting sides :D :D If any condensation gets on your CO2 filter you could poisson yourself... is one of the common causes of accidents with rebreathers!

My hypoxic training consist in keeping the head under the duvet... total relaxation state, low O2 and hight CO2 levels, and for once a painless exercise...

Will: does push the tongue back down the throat limit the contractions???

Actually I came to freediving "from the dark side of the force" a few years ago. I was a back yard trimix blending DIR converted tech diver and now all that gear gathers dust in the shed and my drysuit seals have perished! :duh

I'll never go back!!

It's good that you mentioned the condensation as the scrubber was nice and dry inside until I stopped using it and then the moisture in the system condensed on the side of the container......any hints on how to solve this?

Benny - Sarah was rather unamused by the aquisition of some parts but I think it was the biscuit tin (scrubber canister) that most bothered her. After almost ten years she is finally getting use to losing all of her tupperware containers and measuring cups to mixing resin :)

A couple of questions for those in the know.
1. What blood tests are worth getting before and after embarking on a hypoxic training program
2. What progrmas are typically used for IHT?


Not sure, the one building reabreathers is a friend living on the dark side... and is not having any chance in converting me over :D :D But the way I see your set up, if you train a cold morning one of your your "tracheas" could condensate and some liquid water drop on the filter (I can't see the lung connection, but he looks like that the breath out is on the right, your left ).

It may be safer to breath on the lung, then redirect the flow to the CO2 filter, and place a paper filter to stop any nasty particles on the way to your lungs.

If the lung is at a slight lower pressure than the "trachea" there is a better chance to force any condensation to happen on the lung... you could constrain the lung entry to have a slight pressure build up on the "trachea". If the lung is on a cold middle any condensation should be on the lung... away from the soda lime.
If the filter is higher than the lung, any other condensation should fall away... instead driping in.

The best would be to look at how a reabreather or other similar machine is dealing with the issue...

Yes! I can see the tech diving gear behind you couch... rofl