Static on land question.

[islanderman]

Hi, my question is: if you blackout while practicing, say on a bed or in a chair, how dangerous can it be? I don't fully understand what happens after you blackout. I've never blacked out myself but I do want to know the consequences if I do. Thanks for any info!

 

[jschultzdanmark]

I am not an expert; but since you are not under water your larynx will not reflex-close, and will therefore open the second you black out, and your body will automatically start breathing.

I can not recall having read anywhere of any risks associated with BHs on land (apart from when you'll fall of the bed)

 

[guybly]

I also am not an expert, but during my course, my instructor said that there are two main issues when passing out in dry land, first is falling and hitting your head/ breaking something.

the second is, if in the position you pass out in, your airways wont open or your tongue rolls back in your troat and block your airways.

 

[islanderman]

Ok, Thanks for the info. I was pretty sure that you would start to involuntarily breathe. I lay on my back to practice as there is not as much weight on my lungs as there would be if I was on my stomach. Would there be a better position? Also, i don't plug my nose, so that could be an alternate breathing source right?

 

[baiyoke]

Some people on DB talk about how the body may have a tendency to start samba (and possibly also BO) earlier, if you have samba and blackout a lot. As if the body gets more and more cautious...

So it may be couterproductive to your breathhold capacity if reapeted often...

 

[islanderman]

I am clueles, what is samba?

 

[baiyoke]

Samba or LMC (Loss of Motor Control)
You get a LMC when your oxygen level is too low. When you have a samba you shake (minor to heavily) like an epileptic stroke.

From this thread you might enjoy: http://forums.deeperblue.com/beginner-freediving/64959-how-start-freediving.html

 

[islanderman]

Thanks for the info!

 

[akwaman]

Blacking out on land could be due to filling up your lungs so much that it compresses the aorta, the bloodflow to your brain. It used to happen to me all the time, and only after correcting your posture (not sticking your chest out if in the sitting position) can it be controlled. If you are going to your personal best, it may be due to hypoxia (resulting in LMC) but mostly it is the restricted blood flow to the brain.
Realize as well that filling up your lungs to the max - with all the effort and strain that involves - is not always the best way to train increased breath holds.
If you've been taught controlled pack stretching (don't try it without someone showing you how), it is a good technique to increase the lung volume in patient, graduated phases.
I've found with free diving, the more you hurry, the faster you'll do some damage. ;-)

 

[akwaman]

Blacking out on land could be due to filling up your lungs so much that it compresses the aorta, the bloodflow to your brain. It used to happen to me all the time, and only after correcting your posture (not sticking your chest out if in the sitting position) can it be controlled. If you are going to your personal best, it may be due to hypoxia (resulting in LMC) but mostly it is the restricted blood flow to the brain.
Realize as well that filling up your lungs to the max - with all the effort and strain that involves - is not always the best way to train increased breath holds.
If you've been taught controlled pack stretching (don't try it without someone showing you how), it is a good technique to increase the lung volume in patient, graduated phases.
I've found with free diving, the more you hurry, the faster you'll do some damage. ;-)

 

[trux]

Another way to black out is excessive hyperventilation that results in carotide contraction and high hemoglobin-O2 affinity (hence restricted oxygenation of tissue). A packing blackout is often the result of both - hyperventilation + heart and aorta compression.

 

[akwaman]

thanx again Trux.

 

[islanderman]

Thanks, thats good information to know

 

[Simos]

This is just a personal opinion and I am a relative beginner too but despite the fact that you most likely won't die if you BO dry, it's still equally bad in terms of training as BO in the water.

I've never had a BO so sometimes it's tempting to push on dry just to experience the sensations leading to it once and thus potentially recognise them better in the water but in the end I decided that I didn't want to put my body through that unnecessarily and just stuck with the philosophy that if I dive well within my limits and end the holds when not relaxed anymore, I should be fine. So far so good ;-)

I guess my point is that if you focus on relaxation and don't do things like hyperventilation etc you shouldn't really have to worry about a BO, even dry. Having said this you could BO from other things than hypoxia (eg BP) so definitely lie down for dry holds.