gregor1234
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In terms of air consumption, I have always been very average and never really worried about it much but I've been reading another thread
http://www.scubaboard.com/showthread.php?t=134626
and in it there was a link posted by LavaSurfer to an interesting article about a Cozumel DM who supposedly has phenomenally low air comsumption
http://www.neptunediveandski.com/breathing.htm
I've never heard of him before but the guy is supposedly not just an instructor giving general suggestions but a really-truly gee whiz expert who consistently returns with 1300-1400 when everyone else is burned dry.
In this article the air consumption guru specifically adocates extending the INHALE portion of the breath cycle as opposed to the exhale portion. He aims at a 10:1 ratio between inhale and exhale times.
I've never done this.. whenever I need ot conserve, I've always tried extending my exhale time simple because it was less work to simply hiss out the air over a longer period of time than to attempt the more strenuous diaphragm control that would be required for extending the inhale time.
I have performed some every simplistic calculations using idealizing assumtions and simple diffusion equations and they show a very slight advantage (5-10%) in terms of CO2 transport to extending the inhale versus the exhale portion of the breathing cycle.
Except for the wisdom of the acknowledged expert in the article, I wonder whether the diffusion advantage gained by inhale extension is not more-than-offset by the extra diaphragm work required using that approach.
Anyone tried both methods and perferred one over the other?
http://www.scubaboard.com/showthread.php?t=134626
and in it there was a link posted by LavaSurfer to an interesting article about a Cozumel DM who supposedly has phenomenally low air comsumption
http://www.neptunediveandski.com/breathing.htm
I've never heard of him before but the guy is supposedly not just an instructor giving general suggestions but a really-truly gee whiz expert who consistently returns with 1300-1400 when everyone else is burned dry.
In this article the air consumption guru specifically adocates extending the INHALE portion of the breath cycle as opposed to the exhale portion. He aims at a 10:1 ratio between inhale and exhale times.
I've never done this.. whenever I need ot conserve, I've always tried extending my exhale time simple because it was less work to simply hiss out the air over a longer period of time than to attempt the more strenuous diaphragm control that would be required for extending the inhale time.
I have performed some every simplistic calculations using idealizing assumtions and simple diffusion equations and they show a very slight advantage (5-10%) in terms of CO2 transport to extending the inhale versus the exhale portion of the breathing cycle.
Except for the wisdom of the acknowledged expert in the article, I wonder whether the diffusion advantage gained by inhale extension is not more-than-offset by the extra diaphragm work required using that approach.
Anyone tried both methods and perferred one over the other?