How to reduce air consumption?

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JDelage

Contributor
Messages
317
Reaction score
51
Location
Seattle, WA USA
# of dives
200 - 499
All - what can I do in the next few months to reduce my air consumption underwater? I'm not smoking, and I'm working on loosing weight (it would seem obvious that girth->air consumption). Any other effective technique? Meditation, HIIT training, slow pace aerobics,...?

Thanks,

Joss
 
Dive, Dive, Dive. Work on trim. Make sure your gear is as streamline as possible. Go slow. Efficient finning. Those seem to be the main things listed. Also if you are diving locally exposure protection can make a difference. Being cold = increased SAC.

Of course working out on land can not hurt either.

You are in a great area for diving. There are many groups in the area that have standing weekly dives.
 
Yup - more bottom time. But, I also try to keep my cardio workouts on the top of my exercise list.
 
I'm sure there is a connection between girth and air consumption but sometimes it seems to be inverse. I see a lot of fat old guys who seem to fill tanks rather than empty them. Oh, and whales stay down a long time!
 
Dive, Dive, Dive. Work on trim. Make sure your gear is as streamline as possible. Go slow. Efficient finning. Those seem to be the main things listed. Also if you are diving locally exposure protection can make a difference. Being cold = increased SAC.

Of course working out on land can not hurt either.

You are in a great area for diving. There are many groups in the area that have standing weekly dives.

Totally agree. As an adjunct, be sure your kit is balanced and you are not over weighted. I'm sure Nwcid had that in mind also when he mentioned trim.
 
Swimming is probably best. Increase fitness and comfort in the water and should help you to control your breathing rate.
 
All - what can I do in the next few months to reduce my air consumption underwater? I'm not smoking, and I'm working on loosing weight (it would seem obvious that girth->air consumption). Any other effective technique? Meditation, HIIT training, slow pace aerobics,...?

Thanks,

Joss


Your air consumption is proportional to your exertion underwater and your body's fitness. Both will play a role in how much gas you use, although I would say the first is the primary concern. You'll often hear that controlling your breathing is key to a good air consumption. In part, this is true but only to the extent that your body allows. If your body demands the extra oxygen, then you don't have any choice but to comply.

The fitness, you already have nailed down since you're losing weight and are increasing your body's efficiency. Underwater, you limit your exertion by not making any extra unnecessary movements. Reducing movements begins with good trim and good buoyancy control. Often, you see stationary divers continuously fining or sculling with their hands. It's done to compensate for a lack of trim and buoyancy control. Yes, all this stuff adds up as your muscles are using additional oxygen. Also, when moving from one place to another, it's not necessary to get there at warp speed. Slow down your kicks. Even with a flutter/scissor kick, you'll have a glide component, albeit smaller than that of the frog kick. As you limit your exertion, your breathing will slow down. At this point, you'll be able to take these deep slow breath with long exhales. It's not that you're voluntarily holding your breath, it's that your body doesn't demand the extra oxygen.
 
It actually has little to do with your body consuming oxygen, and more to do with producing less CO2. Your body has more oxygen than it knows how to consume while on scuba.
 
This is a very common question from newer divers, because we ALL want to spend more time down there . . .

Most people who haven't delved into this think that how much air they breathe is determined by how much oxygen they need. That's actually not true at all; the urge to breathe is driven by the body's intense need to keep the level of CO2 in the blood very closely controlled. The reason for this is that CO2 plays a critical role in the acid-base balance of the blood, which has to remain within tight limits for all the chemical reactions of metabolism to proceed as they should. CO2 levels in the blood are directly proportional to the volume of air that goes through the gas-exchange portion of the lung, which is the small air sacs called alveoli. Air you inspire goes through the trachea and major bronchi, which are made of cartilage and don't do any gas exchange, and then into smaller and smaller airways until it reaches the alveoli.

If you think about it, this means that if you breathe in rapid, shallow pants, most of the air you are moving in and out is only encountering those cartilage passageways, and is not getting rid of any CO2. This is called "dead space", and if the breaths you take are small enough, you're only ventilating that. If only ten percent of what you breathe gets down to the alveoli, you have to breathe ten times as often to move the same amount of gas through the important part of the lung, and your tank won't last long. That's the genesis of the advice to breathe slowly and deeply -- it's trying to counter the anxiety-driven panting of new divers.

But once you have gotten through that initial "OMG, I'm gonna die!" reaction, new divers are still likely to have high gas consumption. Why? Because they are inefficient, and the more you move, the more CO2 you make. Your goal is to move through the water with as little effort as possible, in a relaxed state. That's what will minimize gas consumption.

So, how do you cut down on what you do? First off, work on staying in balance. Make sure your gear fits, so you aren't trying to cope with a tank that wants to do an end run around you. Don't swim with your hands, because they're very inefficient -- fins have huge surfaces to grab the water, and give you a much better return on your effort investment. Don't swim fast -- the more you zoom around, the faster your gas will go. And fix the number one cause of inefficiency, which is improper trim. If your body is aimed upward and you kick, you will go up -- if you don't WANT to go up, the only way to avoid it is to be negative. So you then expend a lot of energy kicking upward and getting nowhere. If you are horizontal, any kicking you do drives you FORWARD, which is where you want to go.

You don't have to be thin to have good gas consumption, and you don't have to be strong or even particularly fit, although those are all laudable goals. You have to be relaxed and efficient. It does come with time, but if you don't fix things like improper trim, all the diving in the world won't reduce your gas consumption beyond a certain point.
 
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Things I've found that really help:

1. Good trim (less drag)
2. Carrying no more weight than necessary (less kicking needed)
3. Efficient fins (I've found that fins make a lot of difference. Most efficient I've tried so far are Dive Rites. Easiest fix.)
4. Kicks that use small muscles (Modified frog)
5. Streamlined gear (less drag)
6. Fast and accurate adjustments of air in BCD when needed (so you don't over inflate, deflate and repeat to get the optimum amount of air.)
 
https://www.shearwater.com/products/perdix-ai/

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