Mike,
Let's assume your data is correct (personally, I have no reason to doubt it). This means you and your buddies are able to breathe at a slower rate as depth increases. Let's assume for the sake of the argument that exercise activity, temperature, etc. have all been normed out by the averaging of the sac rates. Is there any theory which would explain the slower breathing at depth?
1. Do you (and your buddies) concentrate on conserving air more effectively at depth?
2. Physiologically -- and I'm no Doctor -- is an individually able to spread out breaths longer at depth naturally? I've only heard that co2 buildup causes the need to breath. I don't know if it is the %of co2 gas in the lungs or the absolute amount of co2 in the lungs that causes the need to breath. I could see, however, if it was the % of co2 in the lungs, that an individual might be able to slow down breathing at depth in a linear fashion. Let's say, at a constant easy activity rate I generate x grams of co2 per 10 seconds at the surface. At depth (say 33' for simplicity), with the same level of activity, I would still generate the same x grams/10 seconds. However, my lungs would contain twice the amount of other gasses (2g).
So x/2g (fraction of co2 at depth) is 1/2 x/g (the fraction of co2 in the lungs at the surface). Therefore, if breathing reaction is triggered by % of co2 (assumption which I don't have any idea if its true), I would feel less likely to need a breath at depth with the same time since last breath (assuming I was able to clear the lungs as efficiently at depth as at the surface with the last breath). Consequently, it would seem possible to slow down breathing at depth.
Of course, this all falls apart if it is the amount of co2 that triggers the need to breathe.
Maybe a doctor or biologist could provide comments to support or repudiate this theory?.
Let's assume your data is correct (personally, I have no reason to doubt it). This means you and your buddies are able to breathe at a slower rate as depth increases. Let's assume for the sake of the argument that exercise activity, temperature, etc. have all been normed out by the averaging of the sac rates. Is there any theory which would explain the slower breathing at depth?
1. Do you (and your buddies) concentrate on conserving air more effectively at depth?
2. Physiologically -- and I'm no Doctor -- is an individually able to spread out breaths longer at depth naturally? I've only heard that co2 buildup causes the need to breath. I don't know if it is the %of co2 gas in the lungs or the absolute amount of co2 in the lungs that causes the need to breath. I could see, however, if it was the % of co2 in the lungs, that an individual might be able to slow down breathing at depth in a linear fashion. Let's say, at a constant easy activity rate I generate x grams of co2 per 10 seconds at the surface. At depth (say 33' for simplicity), with the same level of activity, I would still generate the same x grams/10 seconds. However, my lungs would contain twice the amount of other gasses (2g).
So x/2g (fraction of co2 at depth) is 1/2 x/g (the fraction of co2 in the lungs at the surface). Therefore, if breathing reaction is triggered by % of co2 (assumption which I don't have any idea if its true), I would feel less likely to need a breath at depth with the same time since last breath (assuming I was able to clear the lungs as efficiently at depth as at the surface with the last breath). Consequently, it would seem possible to slow down breathing at depth.
Of course, this all falls apart if it is the amount of co2 that triggers the need to breathe.
Maybe a doctor or biologist could provide comments to support or repudiate this theory?.
