o2 absorption rate

[pingshui]

Today I have been to a doctor for the yearly dive check-up. Everything was fine except for one thing. The speed of o2-absorption from the lungs into the blood is quite slow. It already was last year, but back then I thought this could have been a mistake or temporary or whatever. But it obviously is not. The doctor even asked me if I smoke, but I have never even touched a cigarette or else in my life. Of course I wonder where this might come from, but more important:
What could this mean for my diving?
Do I have an increased risk for BO?
Doesn't it matter at all?
Can I do anything to improve the absorption rate?

I would really appreciate your help and comments!

 

[ericvrp]

Is this what is called something like O2 diffusion rate? I remember I had a check-up a couple of years ago where this was measured to. The doctor back then was surprised that my diffusion/absorption rate was low-ish as well. I think I have the exact number somewhere but not sure.

I can not help you with finding out the effects of this. At the time I was a beginner and my results were improving fast so I reasoned that it must be a good thing. Never gave it a 2nd thought until I read your post. All I can tell you is that I don't blackout easily. I hope there is something wrong with me that can be fixed to get better results.

cheers, Eric.

 

[pingshui]

It could also be called diffusion rate, I just tried to explain what the doctor tried to explain to me
I don't even know which of all the numbers on my results sheet he acutally referred to, I don't understand this medical-chinese. It just is a horrible feeling having "smokers-lungs" without ever having smoked and almost daily doing sports.

 

[hogphish]

I think you are talking about V02 max. This is a general measure of your fitness level and ability to use oxygen. This is done during an "exercise test" on a tread mill or stationary bike. While the concentration of inhaled and exhaled gases are measured.

 

[efattah]

A slow diffusion rate would be extremely beneficial for freediving. It would:
- Ration oxygen supplies and favor earlier use of anaerobic stores
- Delay O2 toxicity at depth
- Delay the vacuum induced blackout in the last few meters of the ascent

 

[Mullins]

My diffusing capacity (adjusted for lung volume) is 69% of expected, which is pretty low. It's not something I'd worry about unless I was presenting symptoms of some kind - and as Eric points out, it might be beneficial.

 

[Unclejake]

[ame="http://en.wikipedia.org/wiki/Diffusion_capacity"]Diffusion capacity - Wikipedia, the free encyclopedia[/ame]

 

[Siku]

Interesting! I wonder if the diffussion rate is slowed by training?

A slow diffusion rate would be extremely beneficial for freediving. It would:
- Delay the vacuum induced blackout in the last few meters of the ascent

Eric, can you explain the mechanism here?

 

[cdavis]

Low diffusion number may well be related to freediving deep and/or diving FRC in some cases. Thickness of the alveolar walls affects diffusion rate. Extreme levels of cardio type exercise lead to thinning of the alveolar wall. Looks like in reponse to the need for high diffusion rates. Conversely, there is some evidence that lots of deep/frc diving leads to thickening of the alveolar walls, in response to stretching from blood shift. That would lead to low diffusion rate.

 

[watts]

How did the doctor work out the diffusion rate. Someone with a very high vo2 max would have a high diffusion rate right?

 

[Mullins]

Usually you inhale a known percentage of carbon monoxide and they measure how much of it you breathe out again.

Deep diving might reduce diffusion rate, but that's clearly not what's happening in my particular case.

 

[Unclejake]

It is fair to assume that people like things they are reasonably good at.

Perhaps all freedivers have low diffusion capacity.

I imagine mine is terrible.

 

[efattah]

What I do know is that for myself and Sebastien Murat, our VO2 max has continued to decrease each year with intensive apnea training. This is not surprising but it is something to keep in mind. Intensive apnea training for long periods will deteriorate your ability to perform at a high level in aerobic sports.

 

[pingshui]

I am glad to hear it's nothing serious and I really appreciate all the great answers.
But one question remains: If it continues getting worse, because I still have some decades of possible training ahead of me, could this become problematic in higher age, like 60+?

 

[trux]

Seing the number of senior freedivers around, and looking at the life span of amas (80-90 years, and often actively diving still after 70 years) I would not fear it too much

 

[Simos]

I have no idea of the mechanism but from a 'black box' perspective, I always assumed that this is one of the goals/results of apnea training i.e. to ration O2 usage and for the body to start working anaerobically as quickly as possible to save O2.

One of the few reasons I can think of that it would be a bad thing (even if beneficial for apnea) would be if part of your lungs have suffered some kind of damage e.g. as a result of squeeze(s). I don't know if that would affect your lung volume as well, or just the diffusion rate.

I am not expert or doctor, but it's worth bearing in mind that when a doctor makes statements about any readings being 'out of the norm' (this is always compared to averages) it doesn't necessarily mean it's a bad thing especially if you've doing specific training for a sport. It could just mean that your body is adapting to whatever activity you are subjecting it too...

 

[Mullins]

I think freedivers tend to overstate the physiological effects of their training a bit. Hardcore, long-term training might stuff up your v02 max a bit (it hasn't affected mine), possibly via neglect rather than active stress compensation. But I'm not sure that the average freediver's training regime would have a profound effect on something like 02 diffusion. As UncleJake pointed out, it could well be a cause rather than an effect. Aside from DR strength we really have little idea what makes some people naturally better freedivers than others - this could be one part of it.

Then again, Trux reckoned the opposite (i.e. low diffusion rate = earlier BO)