Does smoking lower your SCR?

[*Floater*]

In a recent thread somebody posted:

"back before i quit smoking, i consistely had sacs in the .45 area

once i quit, shot up to .8 and above"

i'm wondering if there's anything to this? maybe if a large male reduces his lung capacity to that of a small female by smoking heavily, then his SCR could also fall to that of a small female as well... or is it just a relaxation thing? nicotine gum?

 

[pilot fish]

In a recent thread somebody posted:

"back before i quit smoking, i consistely had sacs in the .45 area

once i quit, shot up to .8 and above"

i'm wondering if there's anything to this? maybe if a large male reduces his lung capacity to that of a small female by smoking heavily, then his SCR could also fall to that of a small female as well... or is it just a relaxation thing? nicotine gum?

I used to be a smoker -gave them up 21 years ago -and have now noticed a reduction in my lung volume/capacity. I was tested several years ago and just passed the lung volume test in the low average range, if I remember correctly. It seems I am more prone ot hypoxia than a normal person that has never smoked. I cannot, for example, hold my breath as long as a person that has never smoked. Xrays indicate my lungs are clear, but that does not show capacity. Have any other former smokers noticed a diminishing of lung volume?

 

[TSandM]

Again, CO2 production determines minute ventilation. A heavy smoker damages his lungs and reduces the surface area available to do gas exchange, making the lung less efficient. He doesn't make them "smaller", or reduce the amount of air that has to be exchanged to keep CO2 normal. People with severe lung injury from smoking can no longer KEEP their CO2 normal and become tolerant to elevated levels, but such people would not be diving -- they're usually not doing very much at all.

PF, the lung volumes that are usually diminished in people with long smoking histories are the volumes of what you can MOVE in a given period of time, not the total lung capacity, although that can be slightly affected.

The only explanations I can come up with for SCR being lower when someone is smoking would be increased CO2 tolerance or some calming effect from the nicotine. To have a difference as great as the person who posted about smoking reported would require a pretty high CO2 tolerance.

 

[pilot fish]

Again, CO2 production determines minute ventilation. A heavy smoker damages his lungs and reduces the surface area available to do gas exchange, making the lung less efficient. He doesn't make them "smaller", or reduce the amount of air that has to be exchanged to keep CO2 normal. People with severe lung injury from smoking can no longer KEEP their CO2 normal and become tolerant to elevated levels, but such people would not be diving -- they're usually not doing very much at all.

PF, the lung volumes that are usually diminished in people with long smoking histories are the volumes of what you can MOVE in a given period of time, not the total lung capacity, although that can be slightly affected.

The only explanations I can come up with for SCR being lower when someone is smoking would be increased CO2 tolerance or some calming effect from the nicotine. To have a difference as great as the person who posted about smoking reported would require a pretty high CO2 tolerance.

Sorry, I'm not understanding the term MOVE, as used here? I notice a difference in how long I can hold my breath and not sure why that is. I wonder if I can increase the time of holding by practice, you know, time myself and see how I improve by increasing the holding time?

 

[Cacia]

wow, Lynne, great explanation. You really have a great gift for explanations.

Lots of these folks were younger when they smoked too. move is "exchanged"?

 

[TSandM]

How long you can hold your breath really depends on where your CO2 is to begin with and how tolerant you are of it increasing. It doesn't have much to do with how much volume is held in your lungs with a breath. CO2 tolerance can be learned, which is why freedivers can stay down as long as they do.

"Move" referred to the air you can get in and out of your lungs. One of the things that happens to smokers is increased mucus and bronchospasm, so that their airways are narrowed and they have problems emptying and filling their small air sacs (alveoli). If you measure the maximum amount of air you can move in and out of your lungs in one minute, that number will usually be lower for a given age and size of person in a smoker, as compared with a nonsmoker.

 

[pilot fish]

How long you can hold your breath really depends on where your CO2 is to begin with and how tolerant you are of it increasing. It doesn't have much to do with how much volume is held in your lungs with a breath. CO2 tolerance can be learned, which is why freedivers can stay down as long as they do.

"Move" referred to the air you can get in and out of your lungs. One of the things that happens to smokers is increased mucus and bronchospasm, so that their airways are narrowed and they have problems emptying and filling their small air sacs (alveoli). If you measure the maximum amount of air you can move in and out of your lungs in one minute, that number will usually be lower for a given age and size of person in a smoker, as compared with a nonsmoker.

I'll have to do some reading on this subject and educate myself a bit. I have no mucus but I'm sure I have narrowing of the airways - I cough a lot, due ro silent reflux so Im sure it is all connected. Orange juice makes me cough, as does coffee, but I will not give them up. Since I gave up smoking so long ago shouldn't those symptoms have disappeared?

If any of you guys still smoke, you really have to rethink that. We had a guy in Grand Turk last month that was lighting up between dives. They should not permit smoking on a dive boat anyway.

I'm going to hold my breath now and see how long I can hold it sitting here. You guys do the same and see how long you can do it?

 

[pilot fish]

1 minute 16 seconds. dreadful!

 

[lamont]

1 minute 15 seconds. i think SAC rate and breatholding are semi-orthogonal, though...

 

[TheRedHead]

1 min. 45 seconds. We used to do this as kids.