Long exhale OK?

[lowwall]

When I'm diving, with each breath I inhale deeply and then slowly exhale deeply. The exhalation can take 20 seconds or more when I'm not exerting myself. Is there any reason not to do this, other than it makes buoyancy control a little more of a challenge? I never hold my breath, the bubbles just kind of continuously dribble out.

I don't know if this makes any difference, but I do have a large lung capacity from swimming when I was growing up and long workouts on a rowing machine as an adult.

 

[Nemrod]

I do the same thing, I see no problem as long as when you ascend that you vent off air sufficiently to prevent lung expansion, exhaling to slowly would not be different from holding your breath. That you are keeping your airway open and effective however makes such a thing unlikely. N

 

[CameronMartz]

When I'm diving, with each breath I inhale deeply and then slowly exhale deeply. The exhalation can take 20 seconds or more when I'm not exerting myself. Is there any reason not to do this, other than it makes buoyancy control a little more of a challenge? I never hold my breath, the bubbles just kind of continuously dribble out.

I don't know if this makes any difference, but I do have a large lung capacity from swimming when I was growing up and long workouts on a rowing machine as an adult.

This breathing pattern is just like when you were swimming the freestyle, and it is the way many divers breathe.

Cameron

 

[spectrum]

You're good to go IMO. Sounds like you are fit and relaxed down there.

I have room to improve on the fitess deptartment but when I'm diving at a relaxed pace I'm surprised at how slow and deliberate my breaths are. Remember that there is elevated O2 in every breath so you have excess oxygen, the deep exhale to vent CO2 is the key. If you feel the urge to vent more vigorously do so. If you find yourself coming out with a headache you might be retaining CO2 and should pick up the respiration a bit.

Otherwise you have found your zen.

Pete

 

[shugar]

wow... this is one of the most useful threads i've read on SB yet! thanks guys!

Jag

 

[jeff99]

Hi lowwall

Relative novice here - used to be a Hoover until my recent trip. Got fed up with using too much air - my GF is a yoga instructor and told me that the best way would be to ignore the inhalation as you would do it when you needed to anyway, and just concentrate on the exhalation - make it slow and long - this way I would be calmer and use a lot less air. She was dead right! My air consumption has decreased by, say 25% and I am calmer and more relaxed u\w! ( She is also a novice by the way, and consistently used less air than the instructors and DM who was with us! ) Also, have no bouyancy issues either - this may just be me. I feel better u\w definately.

Jeff

 

[lowwall]

Thanks all. I guess it is something I learned swimming - thanks for pointing that out Cameron - and it does make a notable difference in air consumption.

I've had people ask how they can improve their SAC rates, but I've been hesitant to recommend this technique because I wasn't absolutely sure there weren't potential problems.

 

[Charlie99]

..... the deep exhale to vent CO2 is the key. If you feel the urge to vent more vigorously do so. If you find yourself coming out with a headache you might be retaining CO2 and should pick up the respiration a bit.

That really is the key. If you are artificially slowing your respiration rate and not elminating excess CO2 from the body you can get into a lot of trouble. Excess CO2 is the suspected cause of many deep water blackouts.

Good buoyancy, no excess movement, and being calm all reduce the metabolic rate and therefore reduce the production of CO2. Flailing around, being excited, or swimming hard all increase the production of CO2 and your breathing rate should go up.

When swimming slowly, my natural respiration rate is around 3 to 4 breathes per minute, but very, very deep breathing. Very deep breathing seems to help a lot. Maybe because it reduces the effect of the dead air space --- air that is being moved back and forth through the throat and upper lungs, but isn't contributing to either O2 or CO2 exchange in the aveoli of the lung.

 

[MookieMoose]

That really is the key. If you are artificially slowing your respiration rate and not elminating excess CO2 from the body you can get into a lot of trouble. Excess CO2 is the suspected cause of many deep water blackouts.

Good buoyancy, no excess movement, and being calm all reduce the metabolic rate and therefore reduce the production of CO2. Flailing around, being excited, or swimming hard all increase the production of CO2 and your breathing rate should go up.

When swimming slowly, my natural respiration rate is around 3 to 4 breathes per minute, but very, very deep breathing. Very deep breathing seems to help a lot. Maybe because it reduces the effect of the dead air space --- air that is being moved back and forth through the throat and upper lungs, but isn't contributing to either O2 or CO2 exchange in the aveoli of the lung.

Excess CO2 has nothing to do with deep water blackout. Quite the opposite, deepwater blackout can usually be traced back to insufficient CO2. Hypoxia is the actual cause of the blackout - not enough oxygen getting to your brain to keep you consious. This happens because low O2 in the blood is not what triggers most people to breathe, but rather it is high CO2 in the blood. By hyperventilating, as some freedivers do, you remove too much CO2 from your blood, but don't load much if any extra oxygen. This can put you in a situation where you consume all the available oxygen before the CO2 level gets high enough to trigger you to breathe again, so you pass out without ever knowing that there was a problem.

 

[Charlie99]

Excess CO2 has nothing to do with deep water blackout.

DAN says otherwise. (Please note that by deep water blackout, I'm referring to loss of consciousness by a scuba diver at depth, not the shallow water blackout of a freediver ascending after a long freedive).
http://www.diversalertnetwork.org/medical/articles/article.asp?articleid=29

Unconsciousness underwater is often associated with deep diving accident reports. It usually results in drowning. A number of conditions can cause a diver to lose consciousness underwater. Such conditions include, but are not confined to:

high blood carbon dioxide levels (hypercapnia);
oxygen toxicity;
nitrogen narcosis; and
decompression illness;

and

Carbon dioxide acts as a respiratory stimulant and can cause depression of the central nervous system (CNS). The effect depends on the level of carbon dioxide in the blood. Deep diving produces elevated blood carbon dioxide levels for several reasons, which include:

the resistance to breathing caused by breathing denser gas through a regulator and against a higher ambient pressure;
reduced ventilation efficiency due to the denser breathing gas; and
reduced transport, and, hence, elimination of carbon dioxide.
Hypercapnia increases narcosis and the likelihood of CNS oxygen toxicity. In addition, it may increase heat loss, alter heart rhythm and predispose to decompression illness. If the carbon dioxide level gets too high, and it can on deep scuba dives -- especially if a diver is very anxious and / or exerting him/herself -- the diver may go unconscious without warning.