Breathing rate and volume

[aainslie]

I used to do a lot of breatholding stuff. It's given me a weird breathing style - deep, long, with big changes in buoyancy as a result and big inhale/exhales. I breathe roughly once for every two breaths of most people I dive with. I'm not entirely sure it's a good thing. My SAC is about the same as most of them, around .7 - .8 on a hectic dive, .5 to .7 on more relaxed ones or during deco. So on a datapoint of just one, I'd say it doesn't make much difference.

Where it DOES help me is OOA situations, or dropping a reg or something like that. If you're used to holding your breath it's easier to be relaxed while you fumble around switching tanks off and on, and trying to find a reg that works. I keep doing this to myself on stage/scooter dives where I switch off all the regs I'm not using to stop freeflows and then regret it when something happens to the one in my mouth. It can get interesting... and it can be useful to remain relatively unpanicked for 20 or 30 seconds while sorting it out.

Overall, I find that it makes me more relaxed under water when under pressure, but doesn't help SAC much.

[sskasser]

I was discussing this very issue with a freediver down in Miami. I was impressed (um surprised actually!) when he joined us at 110' on a wreck for few moments. He's also a scuba diver and related the same experience as Andrew with SAC improvement.

[Sludge]

I'd say it's not related. I can't hold my breath worth a crap (less than a minute), yet I have a lower breathing rate than anybody I've ever dived with.

[phillip1]

I do a lot of breath hold training for surfing big waves and surviving long hold downs, the main difference form traditional breath hold training is that the training we do here involves running underwater holding heavy rocks as long as possible coming up taking only one or two breaths then going back down and continuing, we do this in about 20ft of water and at least 3 times a week, this trains the body to use less oxygen while moving and using the leg muscles (simulating a bad wave hold down), we also do freedives to a max depth of 35mtrs sometimes a bit more. It works very well, as it builds up tolerance and breath hold capabilities in those type of situations dramaticaly, however I think that in diving it only makes a real difference if you need to hold your breath for something, my sac rate is about the same as a normal persons is, no real big difference at all.

[MengTze]

I'd say it's not related. I can't hold my breath worth a crap (less than a minute), yet I have a lower breathing rate than anybody I've ever dived with.

That is by sheer presence of your closeness. Your adonis like body makes many pant.

[FW]

I'd say it's not related. I can't hold my breath worth a crap (less than a minute), yet I have a lower breathing rate than anybody I've ever dived with.

Anybody?

[phillip1]

Anybody?

I think that how in shape you are makes a much bigger difference in sac rate than how good you are at breath holding. Someone in shape will have a much lower heart rate during efforts than someone who is not, so slower breathing rate, less air consumption etc.. ( I think)

[mwenner]

Interesting subject. I know I skip breathe, until I ultimately fall into the rhythm of the dive. (if ever, if it's a short dive) On open circuit, that's causing profile problems. I notice that when I'm finally relaxed, it's seem's like I rarely breathe. I've had that happen instantly on short sump dives, in cold water/wet suit, and I don't know why. I think it's all about state of mind, and it's connection to the body. Relaxed, is less air use, regardless. Is that scientific enough for you Marbry?

[Rick Palm]

Hypercapnia from hypoventilation, and an even higher PCO2 at depth, would seem to me to result in acidosis and reduced mentation -- not exactly assets for cave diving.

[Sludge]

Anybody?

Anybody whose SAC rate I knew.

October 14, 2006, Jackson Blue, we scootered to Stage Rock and back. Bottom time one hour, six minutes. I used 3100psi from a stage 80.

December 29, 2007, Peacock Spring, we swam the Peanut Tunnel to the Peanut Restriction and back. Bottom time one hour, seven minutes. I used 2200psi from a stage 80.

Got any numbers?