Deep dive breath rate?

[northernone]

If you've monitored your breath rate at depth, what's your comfortable relaxed BPM rythmn? Considering mild exertion.

For mine it's 3-4 breaths per minute: steady inhale, comfortable pause, relatively forceful exhale (mouth and nose if gas density is a significant factor) immediate repeat. If I skip breathe I get horrible headaches upon ascent so I have developed this rhythm in replacement. I won't force myself to it, but it now feels natural.

Any observations on comfort or clarity depending on your breathing pattern?

Regards,
Cameron

 

[TONY CHANEY]

Well there are just too many variables to say for sure. Open circuit while swimming maybe around 5-6. With OC with scooter 3-4. Rebreather swimming 7-8 and with scooter 5-6. When I am on open circuit I sip, sip, sip, sip, pause and exhale. On the rebreather, which is quite new to me, I can't do the sip so I tend to breathe more. I believe that it is all about minute ventilation and I get a much larger tidal on open circuit than I do on the rebreather so in order to maintain a proper minute ventilation you have to breathe more.

 

[tbone1004]

never something I've tracked. Like @TONY CHANEY it's all about getting to a certain ventilation volume per minute vs. number of breaths.

normal tidal volume is apparently around .5l and while walking with a purpose is between 1-2. so for @northernone to breathe 3-4bpm and maintain say a .4cfm or 11lpm sac rate, that's about 3l per breath or 6x the normal volume. I know I try to breathe more frequently with smaller breaths because I am prone to hypercapnia if I skip breathe, and 3-4bpm would definitely be considered skip breathing in my book.

8bpm seems pretty reasonable for me, but i'll try to track a bit of it on the next dives. What was interesting to read though is that you can't ever track your own true breathing rates because as soon as you pay attention to it, they slow down by 2-3x and we breathe deeper as a result.

 

[northernone]

never something I've tracked. Like @TONY CHANEY it's all about getting to a certain ventilation volume per minute vs. number of breaths.

normal tidal volume is apparently around .5l and while walking with a purpose is between 1-2. so for @northernone to breathe 3-4bpm and maintain say a .4cfm or 11lpm sac rate, that's about 3l per breath or 6x the normal volume. I know I try to breathe more frequently with smaller breaths because I am prone to hypercapnia if I skip breathe, and 3-4bpm would definitely be considered skip breathing in my book.

8bpm seems pretty reasonable for me, but i'll try to track a bit of it on the next dives. What was interesting to read though is that you can't ever track your own true breathing rates because as soon as you pay attention to it, they slow down by 2-3x and we breathe deeper as a result.

You've touched on one of the main issues. Hypercapnia.

Deep, my mentors taught me the importance of shifting from surface TV towards breathing dipping into what would terrestrially be VC range and IRV.

It's about "dead air". You can still breathe whatever your RMV is but breathing pattern determines the ratio it is mingling fresh air with the co2 ladened ERV.

As for measuring: Just listen and count the last time you've been relaxed on a deep dive video. Like you mentioned, if you try to count in real-time it screws the findings.

Cameron

 

[tbone1004]

@northernone taking big breaths in doesn't do anything for hypercapnia, it's about fully exhaling and on CCR's the instructors should be talking about breathing patterns and the "cough" that you are supposed to do to push the last of the volume out of your lungs. Doesn't usually matter on OC, but every once in a while you'll catch yourself taking a "big breath" to clear anything out, but it doesn't have to be every breath.

so watching a video of me scootering, 5bpm is what I consider "long". That's a very low SAC rate for me, typically around .35-.4, and similar to my deco sac rate. On OC kicking around, it's was 8bpm which is my "normal" sac around .5-.55 ish. When I move up to .6-.65 the volume increases but the rate stays about the same.

 

[northernone]

@northernone taking big breaths in doesn't do anything for hypercapnia, it's about fully exhaling and on CCR's the instructors should be talking about breathing patterns and the "cough" that you are supposed to do to push the last of the volume out of your lungs. Doesn't usually matter on OC, but every once in a while you'll catch yourself taking a "big breath" to clear anything out, but it doesn't have to be every breath.

You might find researching this to be interesting. I'm off for a dive now, perhaps I can track down some of the studies this evening. (It's particularly significant in freediving prebreathing and the dangers of hyperventilating.)

I think your mention of a big breath to "clear everything out" might be a significant starting point to considering the affects of breathing pattern on co2 levels in the lungs.

 

[Schwob]

As for measuring: Just listen and count the last time you've been relaxed on a deep dive video. Like you mentioned, if you try to count in real-time it screws the findings.

Oh, gosh, thanks for adding that in hindsight rather obvious thought. It completely escaped me while wondering how to monitor w/o affecting behavior.

I find this topic quite interesting, because I will learn something from monitoring -I am sure. I suspect my breathing rate is way faster (yet deep) than your guys' and may explain why I still use so much gas. Once confirmed I still will be puzzled about what to do about it as I just breathe a lot, even sitting and typing this, but I know what to aim for at least. How, that may be another thing...

 

[leadduck]

@northernone taking big breaths in doesn't do anything for hypercapnia, it's about fully exhaling and on CCR's the instructors should be talking about breathing patterns and the "cough" that you are supposed to do to push the last of the volume out of your lungs. Doesn't usually matter on OC, but every once in a while you'll catch yourself taking a "big breath" to clear anything out, but it doesn't have to be every breath.

So for OC, what breathing pattern eliminates CO2 most efficiently with the smallest amount of gas consumed?

I think it will be something like this: from the resting position at the low end of TV, exhale deeply to expire the ERV full of CO2, then inhale to the upper end of TV, then exhale very slowly to the low end of TV, then rest there.

 

[TMHeimer]

I know it doesn't sound very "professional" or experienced, but I've never thought about my breath rate, deep or shallow. I THINK I breath rather slowly. I think breathing from the mouth naturally goes slower. I've been breathing the same way since I got OW certified. My air has always seemed to last well long enough for whatever I want to do on the dive.
I didn't check a number on the poll because I would think that to find out you'd have to consciously count the number of breaths per minute. That would mean you may alter what you normally do, I would think.

 

[Bubblesong]

When I run, i breath in four steps and out four steps, and I do try to breathe all the way out. I then used the same pattern for swimming kicks and for Scuba. I never paused nor skipped breath since my body does not pause in consuming oxygen.