Lowering SAC rate -- How long does it take?

[TSandM]

In answer to the original question, of how long it takes to reduce your gas consumption rate (happy, Peter?), it can apparently take years. I noticed about a year or so ago, that my gas consumption had suddenly taken a consistent drop. And this fall, it's gone down again (it's weird -- I cannot for the life of me figure out WHY). So I guess as you dive and dive and dive, it can keep decreasing!

 

[vladimir]

It's a bit like referring to a stockholding as "inventory", whereas that is merely a list of what's there, not the stock itself.

At the risk of inviting yet another tiresome harangue, let me point out that in the dialect of English predominantly spoken in the United States (and on Scubaboard), "inventory" does, in fact, mean "the stock itself."

in·ven·to·ry   
[in-vuhn-tawr-ee, -tohr-ee] Show IPA
noun, plural -to·ries, verb, -to·ried, -to·ry·ing.
–noun
1. a complete listing of merchandise or stock on hand, work in progress, raw materials, finished goods on hand, etc., made each year by a business concern.
2. the objects or items represented on such a list, as a merchant's stock of goods.

That is your cue, Peter, to hold forth on how poorly we speak English in the United States (along with our many other failings), how the Oxford English Dictionary does not contain definition 2 above, and how an American dictionary can't be regarded as an authoritative source.

 

[peterbj7]

At the risk of inviting yet another tiresome harangue, let me point out that in the dialect of English predominantly spoken in the United States (and on Scubaboard), "inventory" does, in fact, mean "the stock itself."

Not so. Speaking as an English FCA and an American CPA, I can tell you that common parlance is not the same as precise language, and on this correct American usage is the same as British English. The word "inventory" means "a list". This is not an American vs. British thing - there are as many people in Britain who mis-use specific technical terms as in America.

 

[vladimir]

I'll leave you to argue the point with any of the dictionaries that explicitly disagree with you.

 

[Aaron528]

I understand the things I need to do to lower my sucky (pun intended) SAC rate. How many dives did it take folks to get their rates down to acceptable levels? Any tips?

I'm a psychotherapist, and among other things I help my clients reduce anxiety through breath control. I agree with other posters that doing dives and "relaxing" is the best way to reduce air consumption. But there are a few things you can try while on land that may help. Using the below techniques I got my own SAC rate to below 0.4 in about 2-3 months.

1) Learn to control breath through meditation. Slow, deep, regular breathing is not natural except when we are asleep (and not dreaming). When we are awake, there are all sorts of stimuli that divert us from the kind of breathing we achieve during deep sleep. Meditation on/controlling breath can get us very close to that state. The best is to take a yoga class during this winter that focuses on breath control, but there are a few books you can buy on Amazon or borrow that will help you get started on your own.

The Tao of Natural Breathing: For Health, Well-Being, and Inner Growth

Pranayama Beyond the Fundamentals: An In-Depth Guide to Yogic Breathing

Free Your Breath, Free Your Life: How Conscious Breathing Can Relieve Stress, Increase Vitality, and Help You Live More Fully

All available on Amazon for under $10.


2) Practice breathing devices like Ultrabreathe or Powerlung are also documented to help boost lung performance in all sorts of sports activities, including diving. The only one I actually tried (borrowed) was the Ultrabreathe... it costs about $40. The Powerlung is about $100 and I'm not sure either of them is really worthwhile considering how far you can go just by focusing your mind.

Enjoy...

 

[scubadada]

Practice breathing devices like Ultrabreathe or Powerlung are also documented to help boost lung performance in all sorts of sports activities, including diving. The only one I actually tried (borrowed) was the Ultrabreathe... it costs about $40. The Powerlung is about $100 and I'm not sure either of them is really worthwhile considering how far you can go just by focusing your mind.

Be careful what you read online. To lower your SAC, dive. Work on your buoyancy, your trim, your efficiency of diving. General conditioning and aerobic fitness should help. Relaxation helps too. On the other hand, I believe breathing trainers are bogus, for all sports, not only diving. Though I believe I've read negative trials of such devices, I could not easily find anything, positive or negative on PubMed. Be skeptical of unsupported claims.

If our psychotherapist diver friend has substantiating data, I'd be the 1st to want to see it.

Good diving, Craig

 

[Aaron528]

Be careful what you read online. To lower your SAC, dive. Work on your buoyancy, your trim, your efficiency of diving. General conditioning and aerobic fitness should help. Relaxation helps too. On the other hand, I believe breathing trainers are bogus, for all sports, not only diving. Though I believe I've read negative trials of such devices, I could not easily find anything, positive or negative on PubMed. Be skeptical of unsupported claims.

If our psychotherapist diver friend has substantiating data, I'd be the 1st to want to see it.

Good diving, Craig

I think I stated that the benefit of those devices is questionable, considering how far one can get just by training the mind. I mentioned them anyway, because I had some personal experience with one of them and found it a little helpful. I don't know if they're truly bogus or not. I don't think there's been enough interest in the portable models in professional sports to justify the money that would have to be spent on accumulating "substantiating data" one way or the other. That in itself seems to suggest that portable breathing trainers are, at best, a gadget with limited benefit. But I also doubt they're harmful except perhaps to someone with a serious lung condition. Anyone with that sort of problem isn't likely to be diving. FWIW, professional versions of breathing trainers are sometimes used in PT for people who have experienced tissue damage due to cancer, among other conditions. But those devices employ biofeedback technology, they are expensive, and they need to be operated by professionals.

OTOH, there also hasn't been a lot of data (at least none I'm aware of) correlating meditation and breathing techniques with scuba diving, but that doesn't mean it wouldn't be helpful. Meditation, mindfulness and breath control are well documented for controlling anxiety, and anxiety seems to be a major cause of new divers using up their air more quickly than experienced divers. It's easy to tell someone to "just relax"... but it's more helpful to actually show them how they can do it.

 

[Aaron528]

Be careful what you read online. To lower your SAC, dive. Work on your buoyancy, your trim, your efficiency of diving. General conditioning and aerobic fitness should help. Relaxation helps too. On the other hand, I believe breathing trainers are bogus, for all sports, not only diving. Though I believe I've read negative trials of such devices, I could not easily find anything, positive or negative on PubMed. Be skeptical of unsupported claims.

If our psychotherapist diver friend has substantiating data, I'd be the 1st to want to see it.

Good diving, Craig

Interesting that I did use the word "documented", suggesting there is data to support a claim that they are beneficial. It would have been better for me to stick to mentioning my personal experience, and the anecdotal results I've heard from others. In hindsight, I was thinking of the professional versions sometimes used by professional trainers, not the portable models listed online. I am not aware of any "documented" study recommending benefits of those devices.

 

[Aaron528]

Be careful what you read online. To lower your SAC, dive. Work on your buoyancy, your trim, your efficiency of diving. General conditioning and aerobic fitness should help. Relaxation helps too. On the other hand, I believe breathing trainers are bogus, for all sports, not only diving. Though I believe I've read negative trials of such devices, I could not easily find anything, positive or negative on PubMed. Be skeptical of unsupported claims.

If our psychotherapist diver friend has substantiating data, I'd be the 1st to want to see it.

Good diving, Craig

Literature and studies about this subject are not generally available online; most of the work I've heard about is published in journals related to respiratory therapy. I found a couple of exceptions...I've met Jolie Bookspan and there are a few links inside the short articles she published online.

Respiratory Muscle Training for Better Health and Exercise

Respiratory Muscle Training for Swimming, Diving, and Running

 

[udtfire]

dive dive dive sac is a direct reflection of your comfort in the water