Improving SAC? - tips for lower air consumption?

[TSandM]

mpgunner, if you would like to get together and do a dive or two and talk about some of these things, I'd be more than happy to do that. I'm headed for Mexico on Saturday for two weeks, but get hold of me after the 10th of May and we'll go diving, if you want.

 

[mpgunner]

Thanks, I'd like that. Probably closer to June would work best. I'll send you a note.

 

[8thElementDiver]

Two things can help your SAC tremendously: meditation and improved cardiopulmonary fitness. Doing the things that TSandM mentions will certainly help, but you should be able to get there in 10 to 20 dives. After that, it's nearly impossible to improve your SAC simply by diving more. To continue to improve your SAC you'll have to improve your physical fitness, and regular meditation will also help.

As Capt. Dale mentions, martial arts are great for improving meditation. Yoga is also great for it. We discuss meditation in our book, Yoga for Scuba Divers, and have received feedback from divers that it's really helped them. Meditation is something you can do at home, or in the water just before a dive. Active meditation at home can train your body to take those long deep breaths, and eventually it will become a habit, replacing those short shallow breaths that most people take while sitting around.

As for cardiopulmonary fitness, I can't recommend swimming enough. I swim with a snorkel. (If your dive snorkel drags too much, they make special swimming snorkels that go up along the forehead, between your eyes--it really works well.) Using a snorkel causes me to deal with a larger dead air space than I'd have to deal with while diving, which means I have to take long deep breaths or I'd only be rebreathing my own CO2. And using the snorkel has definitely improved my VO2 max (which is a measure of oxygen uptake, and how efficiently your body uses the oxygen in each breath). When I started regularly swimming 5 months ago I could do only 5 laps; now I'm up to 40, which is more than a mile. (The other benefit is pushing yourself for that "runner's high"; I've gotten buzzes from swimming that have lasted for hours afterward.) After 5 months of swimming 3 times a week, my cardiopulmonary health is the best it's been since I took martial arts 15 years ago. I used to regularly ride stationary bikes but never achieved the results I've gotten from swimming.

To summarize:
- Improve your dive trim and underwater efficiency.
- Learn and use meditation techniques.
- Swim with a snorkel to improve your physical fitness and VO2 max.

And once you improve your SAC you'll be diving longer, so you'll definitely want that dry suit!

 

[rongoodman]

Mine has dropped quite a bit over the last 18 months. I'm in decent shape these days(Denali in four weeks!!), am flatter in the water, and hardly ever use anything other than a frog kick anymore. Between the three, the difference is significant. I still get wound up and breath too much.

 

[JeffG]

dive more.

get in shape

try yoga

 

[El Cid]

I've got a question then. Do some folks have larger lungs than others? I consider myself in good health (just finished a 10k in 51 and a half minutes) and I dive enough to be comfortable underwater aside from the initial cold shock until the wetsuit catches up. I admit to being slightly overweighted now but thats from my purchase of steel tanks, and I'm adjusting to that.

I'm wondering though about lung size since I've had those stupid little games with friends and when I blow up a balloon, I can inflate it to 1.5x to twice the size of some friends. This "theory" (cough) would mean that for every inhalation, I have a larger dead space in my lungs that fills with air that never contacts the walls of the alveoli. With 100cf tanks I can't even keep up with my roommate (who doesn't work out but is certainly smaller build) on 80's. I'm interested in starting yoga breathing / meditation, but was wondering if anyone could comment on this aspect of it.

 

[Mari64Adventure]

You may also consider taking a few yoga classes. There are many benefits that come from yoga not only getting to know your own breath.

 

[perdidochas]

The most effective advice to be a five foot tall 90 pound female. Some one like that can dive for over and hour using 65 cu ft tank

yep, and teh worst advise is to be a new diver who is a teenaged male who's slightly nervouse underwater.

If the above is not possible then the following applies to everyone

If you get more physically fit you will use less air.

Then after that the idea is to burn less O2. You have to move less and move slower. Do that by being more streamlined, better weighted, no unessary moves. and finally relax. being tense burns O2. Even breathing requires effort, do that slower.

The people I dive with who are really good on air don't move a lot they are not zipping around like seals and messing with their gear.

Exactly.

 

[TSandM]

Unless you are freakishly large (somebody 6'10" is going to have a long trachea!) the dead space isn't going to be that different, even if you have a big chest volume. The dead space is the length of your trachea and major bronchi, and it will be slightly bigger in bigger people, but not markedly so. However, bigger people have more total metabolism, so they use more gas.

 

[perdidochas]

As for cardiopulmonary fitness, I can't recommend swimming enough. I swim with a snorkel. (If your dive snorkel drags too much, they make special swimming snorkels that go up along the forehead, between your eyes--it really works well.) Using a snorkel causes me to deal with a larger dead air space than I'd have to deal with while diving, which means I have to take long deep breaths or I'd only be rebreathing my own CO2. And using the snorkel has definitely improved my VO2 max (which is a measure of oxygen uptake, and how efficiently your body uses the oxygen in each breath).

I never thought about the differences in breathing when snorkeling before. I always assumed my fairly good consumption was due to being relaxed in the water. Now, I think doing a lot of snorkeling also helped it out.

To summarize:
- Improve your dive trim and underwater efficiency.
- Learn and use meditation techniques.
- Swim with a snorkel to improve your physical fitness and VO2 max.

Good ideas.