Tool for increasing hypercapnic and hypoxic tolerances

[Padowan]

I'm a newbie to Freediving, just got my AIDA 2* certification the other week, but am getting quite into the sport at a worring speed.

I'm a technical rebreather diver normally and a safety diver for freedivers, and started freediving for a bit of fun, but am really enjoying the physiological and and phycological challenges that it's giving me.

I have started playing with table training to build up CO2 and low O2 tolerances, and have been thinking that as a rebreather diver, I have a piece of equipment that I could use to simulate both of these gas conditions. I could configure and operate my rebreather in such a way as to give me a consistently lean O2 mixture, or an increased CO2 level - I won't go into the details of how I would do this as it's not relevant for my question...

My question is that by doing this I could condition my body to tolerate breathing hypercapnic or hypoxic gasses - the key work here is breathing, not holding. So could I expect to build up my static tolerances by breathing or is it the combination of +CO2 -O2 AND the breath-hold that triggers the development?

It's all hypothetical at the moment, but I'm a bit of a geek when it comes to this kind of stuff!!

[BennyB]

Check this thread out.... you rebreathers are all a funny bunch!

http://forums.deeperblue.net/showthread.php?t=58742

Cheers,
Ben

[Jon]

Which rebreather are you using?

I could see using it to breath lean 02 mixtures, but how are you going to simulate high C02 unless you remove your scrubber?

There are various hypoxic tents, and other systems, out there that allow you to simulate high altitude, low 02, but they are pretty expensive. Since you've already spent the cash on a rebreather you've already got a huge head start.

I've read about running a rebreather with the scrubber full, but no gas, and it would allow you to breath right up until you pass out- so you could feel what it's like to black out while sitting on your couch.

Jon

[Padowan]

I've done hypoxic and and hypercapnic "trials" sitting on the couch to experience these feelings. Breathed the oxygen down to about 5% before I started feeling light headed, and with no scrubber in place, I breathed the unit for about 2 minutes before feeling a rather urgent desire to breathe something fresher!

I've got an Inspiration, and the method I was planning on using for both low O2 and increased CO2 was to breathe the gas round and round and venting a small amount on each exhale, and replacing it with fresh air. The amount I vented (and replaced) each cycle would dictate the oxygen level that the loop would stabilise at, and by doing the same with no scrubber would also dictate the level of increased CO2.

Measuring the O2 content is easy with O2 sensors, but getting an idea of the CO2 would have to be done by calculations (based on exhaled O2 reduction and an assumed CO2 generation), and therefore be rather inaccurate and non-quantifiable.

[samdive]

Mr CROCS set your rebreather up for this now!!! I need to train!!

: )

guys - this is QUITE an expensive tool for freedive training!! but a neat idea if you have one in the garage....

[Padowan]

Originally Posted by samdive

Mr CROCS set your rebreather up for this now!!! I need to train!!

: )

guys - this is QUITE an expensive tool for freedive training!! but a neat idea if you have one in the garage....

Is that "If you have one in the garage that you're not using much these days cos you've been drawn to the dark side"....

[crocs]

if by the "dark side" you mean getting splashed and pulling loads of ropes... then yes.....

now it looks like I'm gonna lose my Inspiration for the good of the UK Team

Thanks Mate!

Coach Crocs

[BennyB]

Originally Posted by crocs

now it looks like I'm gonna lose my Inspiration for the good of the UK Team

And the odd Aussie ring-in

[Padowan]

Originally Posted by crocs

if by the "dark side" you mean getting splashed and pulling loads of ropes... then yes.....

now it looks like I'm gonna lose my Inspiration for the good of the UK Team

Thanks Mate!

Coach Crocs

Don't worry - I'm gonna knock one up out of an old Sofnolime tub. Should be a fun little project - I have a cunning idea for making it automatic (both venting and fresh air addition) so that you just breathe off it, and adjustable (to tailor the resultant PPO2) to give you the level of hypoxia you desire...

At last I can find a use for some of my old Sofnolime too...

[jimmyv]

For CO2 why not breathe through a length of hose? (3 to 6 feet ought to do it) Wouldn't your exhalations have ever increasing amounts of CO2?