Do You Feel The Need To Breath?

[Devil505]

I have been diving for many years but since holding your breath while ascending is a great way to commit suicide, I have never tried anything other than breathing normaly on ascent. My question is this:

If a diver takes a full breath of air at depth & blows continually all the way to the surface, will the expanding air in his lungs (while ascending) make him feel like he doesn't need to inhale or breath? (even if he started his ascent from a great depth) Let's rule out the danger of the bends & the need to decompress for the sake of discussion & keep this purely a theoretical exercise. Theoriticaly, could a diver ascend from ........say a mile down....... & blow all the way to the surface without feeling the need to inhale?

 

[JahJahwarrior]

No. the need to inhale is triggered by the CO2 in your lungs. Even with full lungs, you should still feel a need to inhale after a while because of the CO2 in your lungs. However, free divers can hit something like 400 feet. If they can do it, then we shouldn't have any problem ascending without breathing from 100 feet, right? :14:

 

[wreckchick]

When I finally learned to do a proper CESA (this is NOT a cesa thread) I was surprised at how easy it was to exhale continuously to the surface while making a very controlled ascent from deeper than I thought it would be comfortable.

That said, it's not empty lungs that cause the urge to inhale, it's CO2 build-up as was previously mentioned.

Rachel

 

[CJ Waid]

I don't think so, since the urge to breath is neurological not because you actually NEED oxygen. I learned to intentionnally hyperventilate before holding my breath (for free diving) it helps take away the 'desire' to breath.

As far as NEED for air:

Your body uses oxygen to 'burn' or release energy, however you want to word it. For example, within a muscle, if the muscle needs energy to do the 'work', the oxygen is vital in releasing energy from stored blood sugars. (there are a bunch of other scenerio's too, so this is just an example of one thing that happens)

Once the oxygen releases the energy, the 'work' can be done. It's kind of like the electrical charge that a cord plugged into the outlet provides a vacuum cleaner or something.

Anyway, the brain needs oxygen for the same basic reason, to release or use energy so it can perform its 'work'

How much oxygen the body needs to keep working depends on how much work it is doing. If you are moving your arms and legs a lot, you will be using the same oxygen that the rest of your body needs to do more vital functions like maintaining work loads placed on vital organs. ie. heart beat and simple brain function.

Everyone is different.

The average guy might use 3.5 ml of Oxygen per Kg of body weight. So if he weighs 180 lbs, and is doing NOTHING but existing, he is using about .29 liters of Oxygen just sitting there, now if his heart is beating faster than it normally does at rest, his body is requiring more oxygen for one reason or another. Like if he is working at 70% of his maximum capability, he is probably burning about a liter of oxygen a minute to run his body's functions, which is quite a bit, enough to run a tank out pretty quick.

So as far as could it be done, Yea sure, you will be brain dead in about 5 minutes or so ( although a couple people have proven this to be untrue for them ) but I would say definately within 7-8 minutes.

It takes a little longer to kill the heart, just because the heart is capable of deriving energy from converting stored energy into usable energy through a couple other methods that don't require a lot of oxygen at all.

But, you CAN take away the desire to breath, it is completely a neurological event designed to keep you from doing something stupid, like running out of oxygen.

I would think it wouldn't be much different than smashing your air guage before you go on an extended dive.

 

[CJ Waid]

And yea, the CO2 build up triggers the neurological process, but you can over ride it through tricking your neuropathways, I guess that is pretty much what I was getting at too.

 

[CJ Waid]

Dude, not to totally kill this thread or nothing, but you might want to look into how the lungs work and study it a little, it is pretty interesting, it gives you a whole new outlook on breathing.

 

[Divmstr223]

No. the need to inhale is triggered by the CO2 in your lungs. Even with full lungs, you should still feel a need to inhale after a while because of the CO2 in your lungs. However, free divers can hit something like 400 feet. If they can do it, then we shouldn't have any problem ascending without breathing from 100 feet, right? :14:

Unfortunately I can confirm the accuracy of this statement....:54:

 

[Fotoz4FX]

There is a difference in Free diving and scuba diving in that the free diver does in fact hold the breath from the point of descent to the return to surface with little exhalation if any since the volume of the breath at 1atm is still 1atm at depth... there is no compressed air to release.

As JahJah clearly pointed out, the percentage of CO2 in the system is the triggering point for the urge to take another breath. If it were theoretically possible to take a full breath at 1 mile and exhale in a direct ascent to the surface, the expansion of air could theoretically provide a manageable exhalation all the way to the surface but the percentage of CO2 would still increase and as deep divers know, a person cannot inhale 21% much below 200 feet so the reflex and all kinds of other issues come into play when you get that far.

I think what you are asking is if in a theoretical scenario where all is without variation or conflict, could one theoretically ascend without taking a breath and I guess it would be safe to say 'sure' so long as the exhalation is in line with the ascent rate and it's a perfect world... but it isn't so.

 

[TheRedHead]

I wish people would stop misspelling breathe. It drives me nuts.

breathe
verb (used without object) 1. to take air, oxygen, etc., into the lungs and expel it; inhale and exhale; respire.

breath
noun 1. the air inhaled and exhaled in respiration.

Now, I can breathe easier.

 

[Thalassamania]

If a diver takes a full breath of air at depth & blows continually all the way to the surface, will the expanding air in his lungs (while ascending) make him feel like he doesn't need to inhale or breath? (even if he started his ascent from a great depth) Let's rule out the danger of the bends & the need to decompress for the sake of discussion & keep this purely a theoretical exercise. Theoriticaly, could a diver ascend from ........say a mile down....... & blow all the way to the surface without feeling the need to inhale?

No, first of all the pressure a mile down (and there are lots of other problem that are not appropriate here) would kill you, if just because of the ppO2 you’d be breathing. But anyway the change in pressure with time would not be sufficient to drop your ppCO2 in time to keep you from blacking out (see below).

No. the need to inhale is triggered by the CO2 in your lungs. Even with full lungs, you should still feel a need to inhale after a while because of the CO2 in your lungs. However, free divers can hit something like 400 feet. If they can do it, then we shouldn't have any problem ascending without breathing from 100 feet, right?

The “need to breathe” is triggered first off by a shift in the pH of your blood that results from an increase of dissolved CO2.

When I finally learned to do a proper CESA (this is NOT a cesa thread) I was surprised at how easy it was to exhale continuously to the surface while making a very controlled ascent from deeper than I thought it would be comfortable.

That said, it's not empty lungs that cause the urge to inhale, its CO2 build-up as was previously mentioned.

Dissolved CO2 comes out of solution into the lungs; this raises the pH and thus reduces the urge to breathe. Ascending through the water column drops the ambient pressure and thus the constituent partial pressures which decreases your urge to breathe.

Yes a CESA, even from significant depth, is a lot easier than most folks think. But remember that just as the ppCO2 drops so does the ppO2, and that’s where shallow water blackout comes from.

Dude, not to totally kill this thread or nothing, but you might want to look into how the lungs work and study it a little, it is pretty interesting, it gives you a whole new outlook on breathing.

Good advice that we should all take.

There is a difference in Free diving and scuba diving in that the free diver does in fact hold the breath from the point of descent to the return to surface with little exhalation if any since the volume of the breath at 1atm is still 1atm at depth... there is no compressed air to release.

As JahJah clearly pointed out, the percentage of CO2 in the system is the triggering point for the urge to take another breath. If it were theoretically possible to take a full breath at 1 mile and exhale in a direct ascent to the surface, the expansion of air could theoretically provide a manageable exhalation all the way to the surface but the percentage of CO2 would still increase and as deep divers know, a person cannot inhale 21% much below 200 feet so the reflex and all kinds of other issues come into play when you get that far.


I think what you are asking is if in a theoretical scenario where all is without variation or conflict, could one theoretically ascend without taking a breath and I guess it would be safe to say 'sure' so long as the exhalation is in line with the ascent rate and it's a perfect world... but it isn't so.

See above.