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This may have been discussed before, but does anyone know of a correlation between breath hold ability and gas consumption during diving? i.e. the possibility that if you're very good at holding your breath you can be better at controlling your breathing during a dive.
I can see where you would build up a tolerance to elevated CO2 levels, increasing the interval between breaths, but it seems you might be effectively increasing your tidal volume at the same time.
Marbry
A good point. What do you think about smokers having better SAC rates?Quote:
Originally Posted by Webmaster
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.
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.
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.
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.
That is by sheer presence of your closeness. Your adonis like body makes many pant.Quote:
Originally Posted by Slüdge
Anybody? :roll:Quote:
Originally Posted by Slüdge
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)Quote:
Originally Posted by FW
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?
Anybody whose SAC rate I knew.:twisted:Quote:
Originally Posted by FW
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?
oooh, a breathe-off! i wanna be the chick with the scarf at the start!
Quote:
Originally Posted by MengTze
Russell...sorry bud! But I've dived with ya both and my money's on the guy with the long beard that "breathes like an 8-yr old girl"...although, I have to admit, you remind me of a 12-yr old girl...errrr....I mean you breathe like a 12-yr old girl!Quote:
Originally Posted by BabyDuck
Marci...drop the scarf...let's do this! :smt081
I think what you mean is that you wouldn't be surprised to see me with a twelve-year-old girl!
November 21, 2008, Internet, 1/2 beer consumed reading this thread.Quote:
Originally Posted by Slüdge
RAL
I admit I am not the best in shape person & could stand to drop 25lbs, but my SAC and breathing rate is on average with everyone I dive with. I dive with some guys who are in really good shape and they have higher SAC rates than myself.
It comes down to cardiovascular fitness and how well your body uses the gas you are breathing.
I also do not see a correlation between breath holding and SAC. Like others have mentioned it does help in those "oh ****" times.
SAC rates are also dependent on your "calmness" in the water.
The guy with the best sac rate I have ever seen does not and probably has never exercised, drinks too much and is just all around lazy. Come to think of it most of the people that I know that have lower sac rates than me are lazy fcks.
I think this breath off event should be changed to suck off! Catchy, huh. Probably draw a larger crowd.
I will never win that award but I do have one buddy that really does not use much air at all. I measured his sac rate one time including deco and it figured at 0.29. When we dive together its somewhat of a conversation on how much more I used than him after most every dive. On a real good day I am a little over .5 but most of the time .6 to .7. The worst dive buddy I have ever dove with had over a 1.0 rate and dove LP130s. Most of my dive buddies use about the same as me.
Russell you sound like you might even have a rate lower than my buddy.
As a side note what is the lowest rate you have ever heard of someone consistently having. I heard of a lady from accross the pond with a .21. Any lower?
Tom
That's nice, but it's sort of a negative proof and not really what I was asking. I think we can all agree that individuality plays a large role in SAC including fitness, smoking, state of mind etc... And that certain individuals may seem to be to one end of the scale or another for particular factors which would seem to be contradictory.Quote:
Originally Posted by Slüdge
But, I'm not talking about any of that. For a particular individual, all other factors being more or less the same, can breath hold training be applied as an aid in reducing gas consumption during diving? i.e. SAC before breath hold conditioning vs. SAC after, perhaps with specific attention given to altering breathing patterns to take advantage of that.
And I would say you would probably need to see the same methodology applied across a number of individuals to gain any real insight.
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 !!!!!:smt102 Why ?? Why ?? Why?? :-DQuote:
Originally Posted by Rick Palm
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
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
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.Quote:
Originally Posted by guru caver
It has everything to do with how excited/scared/comfortable you may be on any given dive.
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.Quote:
Originally Posted by Slüdge
later.............^_^
JE
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
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+
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.
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!
I've been told Edd Sorenson's SAC rate is lower than mine, and he outweighs me by probably sixty pounds.
Your SAC rate is of course determined by the volume of gas inspired per breath and the number of breaths per min. Your lung volume is fairly static. You can change the amount of each breath to an extent but each of us has a comfortable volume of each breath we take while diving.
People who have smaller lung volumes are females, shorter people, smokers, non-athletes, and people who live at low altitudes. It takes and extended period of time to change your lung volumes to any extent.
This leaves just your rate per min that you can appreciably change to change your SAC rate. If you fill your lungs to your comfort level each breath, and your lung size is static you can only change the rate you breath.
Several factors affect your drive to breath but the most powerful is CO2 levels. As CO2 rises from a normal of about 40mmHg to 50mmHg the drive to breath takes over and you WILL breath. You can change this set point over time by exposing the chemoreceptors to increasing amounts of CO2. This takes prolonged regular exposure to increasing CO2. It probably doesn't matter if you do this by breath holding or using a paper sack. If you practice breath holding by first hyperventilating you are most likely defeating the purpose.
Quote:
Originally Posted by guru caver
Hehe as big as that boy was, he breathed like a girl !!!!! :-D
ROFL !!!!!Quote:
Originally Posted by BabyDuck
TJ hates it that I smoke.. Tried to quit a couple times, etc, etc. Same 'ole story --
Bad Habits are hard to break.
5'9" , 158 lbs, SAC = 0.567 - 0.498 on most dives.
Now, if I could just give up that habit, prolly could stay under for days on end :)
A thought no one else has mentioned is dead space. Each breath you take ( average for 150 lb.male) has about 150 cc of dead space because of the volume of your trachea and oral phaarynx. this is wasted as far as respiration (gas exchange) is concerned. It stands to reason that slow deep breaths would be more efficient. 5 400 cc breaths would waste (5x150=750 cc) as opposed to 10 200 cc breaths (10x150=1500 cc) being relaxed would allow this. 400 ccs is not a deep breath I just used the easy numbers to visulize.
TommyQuote:
Originally Posted by TommyB
I know a few divers that gave up smoking or at least gave up for awhile and all of them told me their sac rates went up. Seems like it would be the other way or maybe they were just having a fit because they needed a smoke to calm them down? Who knows ? Folks please do not think I endorse smoking as I do not but that just what I have heard.