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RDRINK25
Contributor
Use the min of weight 2lbs and I agree I am overweighted but I am comfortable overweight.
Air consumption
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Use the min of weight 2lbs and I agree I am overweighted but I am comfortable overweight.
ScubaInChicago
Contributor
Overweighted means more gas in the wing which equates to more horizontal drag. More drag equals more energy to move through the water which builds Co2 which forces the lungs to breathe heavier. It's a vicious cycle, take the class, there's lots to learn.
---------- Post added March 21st, 2015 at 09:06 PM ----------
The last O.C. tech dive I did with a bottom AL80 stage lasted for 35 min @ 200' In 2-3 knot currents (worked a bit harder than usual). Deco was a lot better
A lot of things have been mentioned, but one that hasn't is how much or how fast you swim. CO2, as has been mentioned, is the drive to breathe; anything that causes you to make more CO2 will increase your breathing and make you go through gas faster. But if I understand correctly, that these are aquarium dives, I doubt you're swimming much of anywhere Another thing that will drive up your gas consumption is overuse of your breathing for buoyancy. I learned that when I found that putting in tie-offs in the caves blew my SAC rate -- a good friend told me to stop using my breathing to stay neutral while doing so, and my gas consumption fell back to my usual normal.
Another thing that will drive up your gas consumption is overuse of your breathing for buoyancy. I learned that when I found that putting in tie-offs in the caves blew my SAC rate -- a good friend told me to stop using my breathing to stay neutral while doing so, and my gas consumption fell back to my usual normal.I was on a boat the other day. I swear I was the youngest by 10 years (I am 56). I was up after an hour (temp and pressure), most of the rest came up after.
As Peter said, some one has to be first. It's not a contest.
drrich2
Contributor
Pay attention to how you breathe; how much air you take in, how long you pause before & after the breath, and at what rate you breathe.
Sitting at this desk responding to your post, my 'normal' breathing pattern is a small, partial inhalation (I dunno; maybe half or a bit less what I could hold?), a brief (? 1 or 2 second?) pause, a slow exhalation, then a more substantial pause before I inhale again.
Yet divers are often taught to breathe deeply, continuously and not 'hold their breath.' And when I tried pausing after exhalation (skip breathing), I did last longer on a tank but got a severe headache (likely due to CO2 retention). I'm around 6'1", close to 275#, a chubby mid. 40's guy & no athlete who often dives where an AL80 is basically what I can get. So, what to do?
I'll tell you what I do. Not saying you should do it. Not saying anybody else is going to agree with it. Just gonna tell you what I do.
1.) Cut my weight down a good deal over time. Even if you don't 'feel anxious,' I find I naturally tend to take a deep breathe to 'gird myself' for anticipated effort, and going underwater tends to trigger that response. Let...it...out. When I get rid of the extra air, and get more comfortable under water, I need less weight.
2.) While pausing after exhalation gave me a severe headache, I find pausing after inhalation for a longer moment I much better tolerate. While lets me drag out a tank a good deal.
But won't that mean holding my breath and risking over-expansion lung injury (e.g.: arterial gas embolism, pneumothorax or mediastinal emphysema) if I rise in the water column, consciously or unconsciously, especially in shallower conditions whether pressure change with depth change is faster? After all, in another thread, TS&M pointed out even pretty small rises in gas pressure within the lungs are hazardous.
3.) I examined the difference between holding my breath (which generally implies a closed airway; if you gripped me around the abdomen and squeeze, my cheeks might bug out or my chest hurt, but the air couldn't escape, because I'm holding my breath) and keeping my airway open. In the latter state, I can pause my inhalation (basically either keep my diaphragm down, or my chest wall raised, so my lungs continue holding the same amount of air), yet my airway is open. If you gripped me around the waist and squeezed, air would rush out my mouth, because I'm not 'holding my breath.'
4.) I further hedge my bets by taking fairly modest 'regular' breaths, not real deep, avoiding this approach when ascending, and be mindful in shallower water the hazards if the airway does close are greater.
Something I've not explored all that well is diaphragmatic breathing vs. lifting the chest wall; someone once wrote something to the effect he thought diaphragm breathing (lowering the diaphragm) drew air deeper into the lungs, working more effectively (presumably at CO2 removal). I don't know whether that's true or not.
Now, my only experience of breathing is...mine. Me. I don't have the 1st hand experience of being one of you so as to compare my breathing with yours and contrast. And I've read 'different' advice about how to improve SAC; from 'Don't think about it and breath normally' to 'Pay attention and manage your air usage; sip the air.'
And it's quite possible others will take my method apart as dangerous, idiotic, sub-optimal, etc...
I think it's added about 10 to 15 minutes to my dive time on an AL80 in typical aquarium-like Caribbean conditions. We're adults here.
Richard.
Sitting at this desk responding to your post, my 'normal' breathing pattern is a small, partial inhalation (I dunno; maybe half or a bit less what I could hold?), a brief (? 1 or 2 second?) pause, a slow exhalation, then a more substantial pause before I inhale again.
Yet divers are often taught to breathe deeply, continuously and not 'hold their breath.' And when I tried pausing after exhalation (skip breathing), I did last longer on a tank but got a severe headache (likely due to CO2 retention). I'm around 6'1", close to 275#, a chubby mid. 40's guy & no athlete who often dives where an AL80 is basically what I can get. So, what to do?
I'll tell you what I do. Not saying you should do it. Not saying anybody else is going to agree with it. Just gonna tell you what I do.
1.) Cut my weight down a good deal over time. Even if you don't 'feel anxious,' I find I naturally tend to take a deep breathe to 'gird myself' for anticipated effort, and going underwater tends to trigger that response. Let...it...out. When I get rid of the extra air, and get more comfortable under water, I need less weight.
2.) While pausing after exhalation gave me a severe headache, I find pausing after inhalation for a longer moment I much better tolerate. While lets me drag out a tank a good deal.
But won't that mean holding my breath and risking over-expansion lung injury (e.g.: arterial gas embolism, pneumothorax or mediastinal emphysema) if I rise in the water column, consciously or unconsciously, especially in shallower conditions whether pressure change with depth change is faster? After all, in another thread, TS&M pointed out even pretty small rises in gas pressure within the lungs are hazardous.
3.) I examined the difference between holding my breath (which generally implies a closed airway; if you gripped me around the abdomen and squeeze, my cheeks might bug out or my chest hurt, but the air couldn't escape, because I'm holding my breath) and keeping my airway open. In the latter state, I can pause my inhalation (basically either keep my diaphragm down, or my chest wall raised, so my lungs continue holding the same amount of air), yet my airway is open. If you gripped me around the waist and squeezed, air would rush out my mouth, because I'm not 'holding my breath.'
4.) I further hedge my bets by taking fairly modest 'regular' breaths, not real deep, avoiding this approach when ascending, and be mindful in shallower water the hazards if the airway does close are greater.
Something I've not explored all that well is diaphragmatic breathing vs. lifting the chest wall; someone once wrote something to the effect he thought diaphragm breathing (lowering the diaphragm) drew air deeper into the lungs, working more effectively (presumably at CO2 removal). I don't know whether that's true or not.
Now, my only experience of breathing is...mine. Me. I don't have the 1st hand experience of being one of you so as to compare my breathing with yours and contrast. And I've read 'different' advice about how to improve SAC; from 'Don't think about it and breath normally' to 'Pay attention and manage your air usage; sip the air.'
And it's quite possible others will take my method apart as dangerous, idiotic, sub-optimal, etc...
I think it's added about 10 to 15 minutes to my dive time on an AL80 in typical aquarium-like Caribbean conditions. We're adults here.
Richard.
Roman_66
Contributor
I have mostly the same issue. One negative thing that I am not in good physical condition as topic starter. Too heavy for my high.
GUE-F course doesn't improve it too much. I have pretty good trim, no issues with buoyancy and I am not over weighted.
With about 200 dives I always finish dive first, even in the group several new vertical divers, who are smoke between dives.
My SAC about 19-20 liters per minutes, in hot drift dives about 15 liters per minutes.
My buddy friends told me that looks I breath frequent.
It is about one breath each 4-5 seconds. I checked outside if the water : it is about 5-6 second.
If breath frequent is the issue, I don't think that I will be able to change something here.
GUE-F course doesn't improve it too much. I have pretty good trim, no issues with buoyancy and I am not over weighted.
With about 200 dives I always finish dive first, even in the group several new vertical divers, who are smoke between dives.
My SAC about 19-20 liters per minutes, in hot drift dives about 15 liters per minutes.
My buddy friends told me that looks I breath frequent.
It is about one breath each 4-5 seconds. I checked outside if the water : it is about 5-6 second.
If breath frequent is the issue, I don't think that I will be able to change something here.
ScubaInChicago
Contributor
The muscles of the body use oxygen during "Oxidative Phosphorylation", where they make ATP from ADP. ATP is used by the muscle cells to bind two cellular components to slide past each other and contract the muscle (Called the 'Sliding Filament Theory'). Oxygen, as everyone knows, is carried through the blood in Red Blood Cells, on a special molecule called Hemoglobin (Basically a combination of iron and fat). The ratio of red blood cells in a persons blood stream vs other components is called their Hemacrit level (i.e. their ability to transport oxygen). This level of red blood cells can be increased by training at high altitudes (where oxygen levels are low, the body recognizes this and releases a horemone called Erythropoietin, which stimulates red blood cell production in the bone marrow), by 'blood doping', or other methods I won't go into here (normal exercise can increase this level, even if just training at sea level). People who are out of shape, tend to have a much lower Red Blood cell count, and hence their immediate increase in respiratory activity when exercising is in an effort to supply their muscles with more oxygen, as their blood cannot carry as much per breath as a well trained individual. As the body regularly goes into 'oxygen debt', the kidney's release more erythropoietin, and more red blood cells are produced. The lag time between starting exercise, and when you stop breathing rapidly is the amount of time it takes to produce and begin circulating these RBCs.
---------- Post added March 21st, 2015 at 11:46 PM ----------
Also, if you're a smoker, the CO that is inhaled will attach itself to the hemoglobin. CO is 800x more likely to take the spot of o2 and will in essence starve your tissues of oxygen. It's one of the staples of GUE to be a fit non-smoker as the liability and complications of diving with THAT smoking person don't justify the risk. Not to mention it would also be a rule 1 violation
---------- Post added March 21st, 2015 at 11:46 PM ----------
Also, if you're a smoker, the CO that is inhaled will attach itself to the hemoglobin. CO is 800x more likely to take the spot of o2 and will in essence starve your tissues of oxygen. It's one of the staples of GUE to be a fit non-smoker as the liability and complications of diving with THAT smoking person don't justify the risk. Not to mention it would also be a rule 1 violation
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waterpirate
Contributor
In heaven there is no beer, that's why we drink it here!
Your sac rate is based solely on your physical conditioning and body mass. Drop some weight, increase your non diving cardio vascular activities per week, and get some breathing training. You say you are relaxed, but are you really? Be honest with yourself and go after it. There are many breathing and mental excercises that you can do in conjunction with the above to improve your situation.
YMMV
Eric
Your sac rate is based solely on your physical conditioning and body mass. Drop some weight, increase your non diving cardio vascular activities per week, and get some breathing training. You say you are relaxed, but are you really? Be honest with yourself and go after it. There are many breathing and mental excercises that you can do in conjunction with the above to improve your situation.
YMMV
Eric
Forwarning, this is a bit of over simplification...
Gas use is a simple factor of number of breaths and volume of gas with each breath. If you breathe faster, you use more gas. If your lung volume is larger, you use more gas. In general, breathing deeply and slowly, relaxed, is going to use your available gas more efficiently. Rapid, shallow will waste more gas.
My suggestion, yoga. Teaches breath control with movements and relaxation. Seriously. Try it.
Gas use is a simple factor of number of breaths and volume of gas with each breath. If you breathe faster, you use more gas. If your lung volume is larger, you use more gas. In general, breathing deeply and slowly, relaxed, is going to use your available gas more efficiently. Rapid, shallow will waste more gas.
My suggestion, yoga. Teaches breath control with movements and relaxation. Seriously. Try it.
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