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Finless: You couldn't invent him...
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Does anyone know if increasing the breathing rate (on purpose) at deco (not safety) stops is a good idea or bad idea.

To my simplistic view you would think that increasing the flow rate through the lungs, even if only a few breathes a minute,  (esp when on high O2 mixes) would be beneficial to off gassing the excess nitrogen. Like running more trains on the underground at rush hour.

Furthermore, if this did help, there ought to be an optimum breathing rate for each person beyond which the circulatory system would not pass the excess nitrogen to the lungs fast enough and the offgassing rate would decrease in efficiency.

Or, perhaps, start fast and gradually slow down as the excess nitrogen load decreases.

Obviously one would try to avoid hyperventilating. Is becoming hyperventilated such a fine line to cross that, that is why slow, deep and steady is best?

How stupid is that?? Please confine answers to that question to THE question.
 

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A short fat well off crap cave diver. Likes wrecks
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I dont know if breathing rate is important as such but depth of breathing is. Most off gassing takes place in the lower half of the lung and it is preferable to have a long slow steady breath in and out using the diaghpram.

A breath in to the count of 5 and out to the count of 8 focusing on using the stomach to create most of the movement in the lungs it the best method of breathing for off gassing.

My sac for a dive is planned on 15 and my deco SAC is planned on 10. I often get below 15 on the bottom regularly putting in figurs like 12 and 13 but my deco SAC generaly stays arround 10 as I try to regulate my breathing using this method.  

I dont know what the figurs are but generaly fast breathing is a bad thing and deep breathing is a good thing.

ATB

Mark Chase
 

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Finless: You couldn't invent him...
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[b said:
Quote[/b] (Mark Chase @ Sep. 07 2003,17:52)]I dont know if breathing rate is important as such but depth of breathing is. Most off gassing takes place in the lower half of the lung and it is preferable to have a long slow steady breath in and out using the diaghpram.

A breath in to the count of 5 and out to the count of 8 focusing on using the stomach to create most of the movement in the lungs it the best method of breathing for off gassing.

My sac for a dive is planned on 15 and my deco SAC is planned on 10. I often get below 15 on the bottom regularly putting in figurs like 12 and 13 but my deco SAC generaly stays arround 10 as I try to regulate my breathing using this method.  

I dont know what the figurs are but generaly fast breathing is a bad thing and deep breathing is a good thing.

ATB

Mark Chase
Mark,

I follow what you say and, as a long time and fairly regular diver, I know from experience (as well as training/books) that deep and slow is best (works well on other things too).

I just wondered if, whilst at deco stops, where there is a pressure gradient between nitrogen in the body and the ambient pressure of the breathing gas, there was any benefit to increasing the breathing rate (of proper deep breaths) to assist the rate of off gassing? After all, we pant to lose heat, why not breath faster to off load excess nitrogen.

To use my train analogy again, maybe breathing faster doesn't "allow the train to fill up before it pulls out of the station".

My scientific knowledge is nowhere near good enough to understand, let alone draw conclusions from the equations and formulae put forward on the subject. For example, how would you chose which dive profiles are safe and which are not. I have started using Pyle Stops because, having read the article by Richard (?) Pyle, I believed him because he dives a lot and felt better because of the deep stops over a long period.

I am sure my suggestion is incorrect as it seems inconceivable that this would not have already been considered. I am not suggesting panting but maybe upping the breathing rate to (say) 20 per minute MIGHT be beneficial.
 

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A short fat well off crap cave diver. Likes wrecks
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Frankley M8 I dont know the medical side of things. All I can tell you is if you go in the pot they moniter your 02 levels at several points on the body and tell you to breath slow and deep if your levels drop below optimum.

I have read a few books and several articals on deco which sugest that people who dont breath properly dont off gas properly and all have recommended deep breathing but I have never read any thing that states an optimum SAC.

The chaps at Whips Cross are prety cleud up try giving them a call I am sure they wouldent mind answering your quesion.

ATB

Mark Chase
 

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Breathing faster doesn't really, AIUI - but doing GENTLE excercise that itself will increase breathing rates DOES.

What happens is, if you, say, fin along gently, the muscles are doing more work, so the blood flow speeds up, and aids in off-gassing.

It's a fine line, of course, because HEAVY excercise is bad for deco...
 

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Finless: You couldn't invent him...
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I don't suppose acupuncture would work?  
 

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DUE CEO, Booking agent, Coffee maker & Dogsbody...
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Damn

So all the time i've been telling my beginers to stop flapping and fining about while trying to hold a stop is wrong?


Ho Hum back to the drawing board  


So Finless M8 whats done best slow and deep? Thinking maybe?  


Dive Safe

Paul
 

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My guess would be that just making yourself breathe faster makes no difference.  The reason would be that the heart rate is what determines the rate at which your body uptakes the oxygen you breathe in.  Thats why when you heart rate is faster, you automatically breathe faster.   But by just making yourself breathe fast, more of the oxygen will sit inert in your lungs and be breathed back out, Since the blood via the heart rate will only take up the oxygen it requires.
 

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Finless: You couldn't invent him...
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[b said:
Quote[/b] (Wyota @ Sep. 16 2003,21:25)]My guess would be that just making yourself breathe faster makes no difference.  The reason would be that the heart rate is what determines the rate at which your body uptakes the oxygen you breathe in.  Thats why when you heart rate is faster, you automatically breathe faster.   But by just making yourself breathe fast, more of the oxygen will sit inert in your lungs and be breathed back out, Since the blood via the heart rate will only take up the oxygen it requires.
I understand what you say BUT my point is that, at a deco stop where I have a higher volume/pressure? of nitrogen in my body compared to the ambient pressure of the gas I am breathing would breathing faster (maybe only one or two breaths a minute) make the removal of the nitrogen more efficient.

As you say an increased heart rate is caused by the bodies requirement for more oxygen NOT specifically for the offloading of excess nitrogen.

My theory is that there must be an optimum breathing rate to maximise the efficiency of off gassing. The only thing I can see contradicting that is if there is such an over capacity in the breathing system for absorbing nitrogen from the body that the breathing rate makes little or no difference.
 

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Nah - ITYF that gas won't come out of the lungs any faster if you breathe quicker - your lungs are always at ambient pressure, so the speed you breathe won't make any change. You need a higher pressure gradient to get the gas out quicker, ie more gas arriving at the lungs from the bloodstream. That means excercising gently to increase the circulation.

IMHO, of course
 

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Finless: You couldn't invent him...
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[b said:
Quote[/b] (Dominic @ Sep. 19 2003,11:29)]Nah - ITYF that gas won't come out of the lungs any faster if you breathe quicker - your lungs are always at ambient pressure, so the speed you breathe won't make any change. You need a higher pressure gradient to get the gas out quicker, ie more gas arriving at the lungs from the bloodstream. That means excercising gently to increase the circulation.

IMHO, of course
At a deco stop there is an imbalance in the levels of nitrogen in the body and the gas being breathed - I'll call it a pressure gradient - high in the body to low in the deco gas. Breathing is the main method of transporting the excess nitrogen from the body.

Given the fact that exhalation is the main method by which excess nitrogen is transported from the confines of the body then surely it is possible the rate of breathing is liable to have an impact on the effectiveness of the offgassing of nitrogen. Well, in extreme cases we know it does - stopping breathing would certainly lengthen your deco stop times.

A very simplistic view perhaps and maybe a load of crap as well. It was just a thought that maybe each person has an optimum breathing rate for offgassing. It may well be that the difference between optimum and any other normal breathing rate may so insignificant that it doesn't matter.

Persistent aren't I.
 

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Finless: You couldn't invent him...
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[b said:
Quote[/b] ]ITYF
Not on my Nettiquette list.

I have been trying to figure it out - IS TOO YOUR FAULT or, well that was all I could think of.  
 

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"I think you'll find", you iggerant peasant :p
 

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Finless: You couldn't invent him...
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[b said:
Quote[/b] (Dominic @ Sep. 19 2003,14:15)]"I think you'll find", you iggerant peasant :p
That is MR Peasant to you - if you don't mind.  
 
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