How long to you inhale/exhale?

[adza]

.Other possibility is bad gas ? Just breath normaly .

Northern, you could be onto something. The times I experienced it was using a couple of tanks that I had filled at the same time by the same supplier. I just assumed it was my breathing (which it still could be), but it's worth considering if it happens again.

As for the count, I'm around 9 seconds, so it could be that I'm taking too long to exhale all the air, and breath in again, thus building up some CO2 from time to time.

 

[Charlie99]

What works for me is a very long, deep inhale, a short pause, and then a slow exhale. No pause at all after exhale. My underwater breathing pattern is both slower and much deeper than my normal land-based pattern. Normal breathing cycle time is around 15 seconds.

My SAC is about 0.4cfm while ambling around the reef. A 1 knot transit (fairly typical swimming speed) raises that to 0.5 SAC.

For me at least, the key is DEEEEEEEP breathing. Yes, the change in buoyancy will move me up a foot or so, but I'll drop back that same foot or 2 as I exhale and I don't fight or chase it.

 

[DuckyDiver]

My first time diving during a Discover SCUBA tour in St. Thomas the DM had told us to inhale at a regular rate but to exhale for 5 seconds. He said that was the best was to manage air. That was the first and last time I've heard of that method. However, it did seem to work for me during that dive with no ill affect.

 

[Wilson]

Good post, Charlie....

 

[bwerb]

The headache you are experiencing is from CO2 build-up...basically you are skip breathing. Don't do it and the problem will go away.

You shouldn't really "think" about your breathing...your body will breathe as it needs to, just as on land. If you are artificially screwing around with it to conserve air/gas, you are really not doing yourself any favors. If your SAC is too high, time to either relax more or get in better physical shape.

It is amazing how simply relaxing can decrease your breathing...but concentrating on breathing at some such "pattern" of seconds in and seconds out seems like way, way too much thougth over something which your body will naturally regulate as it needs.

 

[divingjd]

A good breathing pattern for scuba is definitely not the same as a natural above-water breathing pattern (except for the kind of breathing you do in a yoga class) and you do need to think about it. Basically, breathing underwater is unnatural and it is a learned behavior. If you don't think about it, you will hold your breath (think back to the first time you put your face in the water with a reg - you probably had to make a concerted effort to keep breathing) and you will breath in the same shallow, inefficient way we all breath naturally. Under normal circumstances, a shallow inefficient breath works well enough, so you don't need to do anything different. But the the most efficient breathing pattern for scuba is a long, slow, deep breath. The key to this is a full exhalation. In normal breathing, we breath off the top quarter (or less) of our lungs. The gas exchange is really pretty minimal. To get the really deep breath that is most efficient, you have to exhale fully first, otherwise you don't have the volume to inhale fully. My underwater breathing pattern is very conscious and very different from what I am doing now. I have never timed it, but I am sure the full cycle is over 10 seconds. I just did a dry run and it looks like something more than 10, but probably less than 15 seconds. If you concentrate on the exhalation, the inhalation will follow pretty naturally. You will be surprised how long you can exhale. The headaches could come from any number of sources, but are most commonly caused by CO2 build-up from skip breathing - short episodes of breath-holding in the breathing cycle.

 

[dive_lover88]

1:3 taught by my instructor

 

[Cacia]

also...the deeper you breathe, the less dead space contributes to the tidal volume, so more gas exchange. hope I remember that right...

 

[TSandM]

As long as you are oxygenating, breathing too slowly isn't a concern.

This is wrong.

Normal, healthy lungs can absorb enough oxygen to keep the level in the blood within acceptable limits, even if the amount of air being moved per minute is not enough to keep carbon dioxide levels anywhere near normal.

CO2 levels in the blood are essentially ONLY dependent on the amount of effective ventilation of the small airspaces per minute, and the body wants very much to keep CO2 levels normal, because they determine blood pH. On the surface, a resting person normally takes about 12 breaths per minute, and moves about 500 ccs of air through the small airspaces with each breath. (This varies with the size of the person, and basal metabolic rate, but the numbers given are ballpark.)

Underwater, you want a somewhat slower respiratory rate, and a larger tidal volume, because that is more efficient (this is related to a concept called dead space, which is the volume of your bronchial tree that doesn't participate in gas exchange). Inhalation is an active process and requires effort; exhalation is generally passive. On SCUBA, you want a slower inhalation than normal, and a passive exhalation, so you are probably looking at about a 1:2 ratio (although I'm not quoting any research, but just assessing my own breathing pattern when I write this).

The important thing is a slow, regular rhythm, with a deeper than normal inhale, and a slow and deliberate exhale, without any breath-holding. Post-dive headaches are probably most common related to elevated CO2 levels due either to shallow, ineffective breathing, or skip breathing (breath holding between inhalations) to try to extend one's gas supply. As CO2 adds to narcosis and changes blood pH, raising the risk of heart rhythm disturbances and other malfunctions, it is not a good idea to change one's breathing pattern dramatically to try to extend your time underwater.

 

[Tigerman]

Since were first on the topic of breath and someone barely touched it, referring to yoga class..
How you breathe controll your heartbeat. Your breathing affect your mental state. This is WHY you take deep, slow breaths in yoga class. It make you relax and lowers your heartbeat.
This is also used for the purpose of hypnosis, which is basically what you do to prevent a panic attack. Self-hypnosis as such. Humans are trance machines that goes in and out of different trances all day. Slow, deep breathing, resulting in slower heartbeat and being more relaxed are the first step towards keeping cool instead of panicing in a stressed situation. Its also the first step towards the kind of trances hypnotists use in stage shows and athletes use to improve their performance. What athletes call "mental training" is basically to put themselves in trances where they perform better..