Breathing rate and volume

[cavediver256]

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.

Oh great Rick !!! Now we have went from a breath off to acid base balance !!!!! Why ?? Why ?? Why??

[MORGAN]

Seems to me that while SAC rate during a dive is affected by a multitude of factors, breath hold duration is based pretty much on one thing - the ability to tolerate hypercarbia during voluntary respiratory arrest. How high can your CO2 go before it forces you to take an involuntary breath?

While the ability to hold your breath a long time may come in handy, I doubt it has much to do with your SAC rate.

Mike

[Cindy]

SAC rate. MMM. I think it's related to:
Gear configuration
Comfort in the cave
Regulator performance
Personal Metabolic Rate- Do breath hold divers have a lower metabolic rate? Fat people vs thin, etc.
Metabolic efficiency- fitness, smoking, lung size, sex, RBC count etc, and genetics.. some people are just blessed
The more dives I have the better all of the above. The more "joy" or comfort I am feeling on a dive relates to that also.
I figured SAC rates all out for classes in the past but find that it doen't help with dive planning.
If I need more gas than I have to do what I want to do then I go back and get stages for the next dive. After enough dives in one cave I know pretty much where I can get on my gas. Comfort level and knowledge of my dive buddies plays a big part. I use more gas when guiding because I spend more time watching than going. If I am with my normal buddies I can hit a stride and cover twice the ground. Cindy

[guru caver]

I don't think that size or weight of the actual person has much to do with it. I know really big people with really good SAC rates and really thin people with really good SAC rates. I definitely agree with it having to do with your own comfort zone.

[phillip1]

I don't think that size or weight of the actual person has much to do with it. I know really big people with really good SAC rates and really thin people with really good SAC rates. I definitely agree with it having to do with your own comfort zone.

I agree, when I am exploring some new caves my sac rate is significantly higher than if it's a cave I know or has been dived before.
It has everything to do with how excited/scared/comfortable you may be on any given dive.

[JE]

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.

If & when I get back into this hook, the one skill I practiced was to find a perch going inside to relax & to lower your exaperations or inhalations. it seemed to work well for me. I still subscribe to doing this. Why bust your butt to rush inside, when a more calm & relaxed attidude will take you a long way in on much less gas or air. Russell is one of few divers I've known who does this. He's the man-! Your food intake also plays heavy on your acr-! keep your fingers crossed, I may try to suprise Cathy & a few others over Thanksgiving.
later.............^_^

JE

[Cindy]

The best advise I ever got was from Steve Forman during my cave class. Don't rush into the water. When you get in the water. Relax, put your face in the cool water. Get your heart rate down. The cave will wait on you. Cindy

[TraceMalin]

I grew up snorkeling and that evolved into an intense love for freediving with 200 foot dives and breath hold times of 5 minutes and 30 seconds and a career as a freediving instructor. Added to which I'm a lifeguard, U.S. Masters swimmer, surfer and I train hard running hills in the Pocono Mountains where I live right now. I started scuba diving at 13 and despite all that my SAC rate for tech diving is average between .7 and .8 cubic feet per minute.

I can lower this to .6 if I do facial immersion and dive wet for slickness to the point of diminishing return where being chilled will cause an increase in consumption. If I'm concentrating on perfect trim, buoyancy, and propulsion like when teaching a class, my SAC rate will be .8+

[Cindy]

Marby, try reading some of Tom Mounts stuff on SAC rate. Interesting stuff.

I know an Alpinist/mountain climber with huge lungs from breathing thin air. He did pretty well on his SAC rate. He didn't have an ounce of body fat.

By far the best SAC rate I have ever seen is Guy Bryant. Another skinny little wart.

I also used to know a fellow who was an open water diver/boat captain when I was wreck diving. He was a static breath hold diver. He had a fair SAC rate with scuba tanks on. He could also do breath hold spear fishing on the wrecks. Those guys are amazing. He died practicing static breath hold diving in a pool. Left a wife and two kids.

How are the games going by the way? I would think that would be just as good a way to practice SAC rate breathing as any of the above.

[guru caver]

does anybody remember a guy named Rob who used to work at Cave Excursions? He was a good sized man and his SAC rate was unbelievable!