breath-hold swim

[nigelH]

Originally Posted by Janos

But if you are pushing yourself, make sure there's someone there who knows what you're doing. I remember once pushing myself, then surfacing, and feeling really woozy for a couple of seconds until I'd got my breath back.

Having pulled a 'samba' after a 25m freedive I've got to agree. Never breath-hold dive alone.

[NotDeadYet]

As I said, use a spotter.

[Prometheus]

Originally Posted by nigelH

Having pulled a 'samba' after a 25m freedive I've got to agree. Never breath-hold dive alone.

Is this in relationship to pressure as well, I have swum underwater in a pool for 30/40 mts and never felt as if I was "pushing" it , wanted to breathe , but no bells whistles or stars in my eyes?.

[Janos]

Originally Posted by NotDeadYet

As I said, use a spotter.

Apologies. Indeed you did. Note to self - must read posts more thoroughly.

Originally Posted by Prometheus

Is this in relationship to pressure as well, I have swum underwater in a pool for 30/40 mts and never felt as if I was "pushing" it , wanted to breathe , but no bells whistles or stars in my eyes?.

No. It's lack of oxygen related, not pressure realted. If you push yourself a bit further, after feeling the urge to breathe, then push yourself a bit further than that, then you'll feel light headed on surfacing. Pushing it too much can lead to unconciousness, which isn't a problem in itself, but is much more dangerous in a swimming pool.

Janos

[Mark]

When I was practicing for my Tech 1 swim test I found it best to start the breath hold swim with full lungs as you can gradually breathe out during the swim and apparantly hold off the urge to breathe in again. It worked for me. I could only do about 10m the first time I tried but with a bit of practice I was able to complete 25m no problem.

[Prometheus]

Originally Posted by Janos

No. It's lack of oxygen related, not pressure realted. If you push yourself a bit further, after feeling the urge to breathe, then push yourself a bit further than that, then you'll feel light headed on surfacing. Pushing it too much can lead to unconciousness, which isn't a problem in itself, but is much more dangerous in a swimming pool.

Janos

So can you overcome the urge to breathe without doing deep breathing before hand,the co2 trigger is still there and hasn't been subdued . I don't take huge breaths before or air pack and am very definite at what point I need to surface, this is normally followed by a localised air pressure drop as I suck in air.

[CatB]

A shallow water blackout at the end of a freedive is caused partly by the pressure change as you come towards the surface, it's related to your lungs expanding again. I'd have to look up the details of the physics and physiology to explain it properly (and I know there are people on here who are better trained in freediving than me) but that's why it's more common at shallow depths than deeper in the dive.

It's not just due to misjudging how deep you can go and running out of O2 before the surface.

However, you can still do that and you can do it quite easily swimming horizontally in the pool especially, as someone mentioned, if you hyperventilate beforehand, you remove more CO2 than you gain O2 so you don't get the trigger to breathe when you need to. I have done a long underwater swim and surfaced feeling a little bit shaky but fine and been surprised that my spotter seemed to have my mask - I had apparently come close to / blacked out on surface and they'd supported me and taken my mask off and I had no recollection of it. It made me realise how easily it's done, especially when you start training yourself to overcome the urge to breathe.

So yes, get a spotter! Oh, and if you are interested in improving how long you can hold your breath have a look over at DeeperBlue.net - Fanatical About FreeDiving, Scuba Diving, Spearfishing & Technical Diving There is some good advice and I found a link to breathold training tables that you do on dry land that increase your tolerance to CO2 and lack of O2 - they are amazingly effective.

Mind you - I still only just made my 18m dive I needed to qualify, 25m is still beyond me!!

As to overcoming the urge to breathe, yes you can train yourself to push through it mentally - I seem to remember it's call the 'struggle phase'!!

[Janos]

Originally Posted by Prometheus

So can you overcome the urge to breathe without doing deep breathing before hand,the co2 trigger is still there and hasn't been subdued . I don't take huge breaths before or air pack and am very definite at what point I need to surface, this is normally followed by a localised air pressure drop as I suck in air.

I'm not quite sure I understand your question. But I don't pre-breathe, and I have been able to push myself to such an extent that I felt woozy on the surface for a few seconds.

If I am pushing myself then I have a 'spotter' as NotDeadYet suggests.

Janos

[Prometheus]

Originally Posted by Janos

I'm not quite sure I understand your question.
Janos

Not sure I do either more research tonight on apnea I think.



P.S. Sorry for diverting thread.

[NotDeadYet]

Originally Posted by WannabeMermaid

but that's why it's more common at shallow depths than deeper in the dive.

Yep, it's similar to why a mix with 10% O2 is breathable at 6m but on the surface will have you on your back. Pressure "artificially" bumps the PO2 up to a level that maintains conciousness, take away the pressure and you take away that boost.

However, you can still do that and you can do it quite easily swimming horizontally in the pool especially, as someone mentioned, if you hyperventilate beforehand, you remove more CO2 than you gain O2 so you don't get the trigger to breathe when you need to.

Golden rule, never hyperventilate. I know I've done it when I've got a bit of a metallic taste in my mouth, I don't know why but I get pain in my temples as well if I hyperventilate.

It made me realise how easily it's done, especially when you start training yourself to overcome the urge to breathe.

I stopped doing a lot of the apnea tables training because one their aims is to build tolerance to elevated CO2. I'd started freediving around the same time I started diving on a rebreather and thought the last thing I want is to become tolerant of CO2. I want the warning signs nagging at me.

Mind you - I still only just made my 18m dive I needed to qualify, 25m is still beyond me!!

Big thing I struggled with was equalising. I can sort of half manage a frenzel which helps.