Anything and everything you need to know to improve air consumption (in currents or otherwise) comes back to two key things from a physiology standpoint:
1.) Air (O
2) consumption is a DEMAND function
2.) Air (O
2) is consumed in your body's muscle cells, not your lungs
Accordingly the most effective way to reduce your O
2 consumption is to reduce the DEMAND that the muscle cells in your body have for O
2. There are 13 key "Demand Reduction Strategies" that any and every diver can employ to improve their O
2 consumption:
- Slow down
- Get more comfortable in the water
- Slow down
- Get your weighting fine-tuned
- Slow down
- Get your horizontal trim dialed-in
- Slow down some more
- Stop swimming with your hands and arms
- Slow down even more
- Utilize efficient kick styles
- Just a little bit slower... please?
- Streamline your gear
- Slow down - you're still moving too fast!
OK, now that we've addressed the best ways to improve your air consumption rate, let's talk a little bit about how a diver should breathe...
There is much advice here on SB about reducing your air consumption by controlling/modfying/focusing on your breathing rate. I won't add anything to those points, other than to say that an awful lot of that advice is largely inaccurate. Let's use a car analogy:
Muscle cells (where O
2 is burned) = cylinders (where gas is burned)
Circulatory system (delivers O
2 to muscle cells) = fuel injectors (deliver gas to cylinders)
Lungs (delivers O
2 to the circulatory system) = gas tank (delivers gas to fuel injectors)
Regulator (delivers O
2 to the lungs) = Pump at gas station (delivers gas to car's gas tank)
Scuba tank (where reg gets O
2 from) = Storage tanks at gas station (where pump gets gas from)
Suggesting that you can meaningfully improve your air consumption by controlling how often, how much, and how slowly you put air into your lungs is like suggesting that you can improve your car's gas mileage by reducing the number of times you purchase gas, always filling and emptying the tank completely, and pumping the gas into your tank slowly. Those are all SUPPLY strategies... but remember, O
2 consumption is a DEMAND function. (Note - for simplicity of this post, I'm not addressing the "exhaust" portion of the equation, since the question was about "consumption.")
Now, before anyone bites my head off, I'm not saying that things like breathing rate, speed, and depth are absolutely unimportant. I'm merely point out the fact that - just like our car analogy - assuming we don't try to deliver more or less O
2/fuel to our muscle cells/cylinders than they DEMAND everything will be fine. Sure, if we don't deliver enough - or deliver too much - O
2/fuel our "engine" will run rough and waste some fuel. But if our lung/gas tank function is within a normal range... our body/car will run fine and we don't need to worry about these things.
Accordingly, I will politely disagree with people who say "focus on your breathing at all times" or those who will offer advice about how many seconds to inhale and how many seconds to exhale and the like. My advice on breathing rate, depth, etc is as follows:
- Breathe normally
- If there is a problem causing you to breathe abnormally, fix the problem
- Breathe normally
- STOP focusing on how you're breathing!
- Breathe normally
- Ensure that the 13 "Demand Reduction Strategies" listed at the top of this post are second nature, so you can STOP focusing on those things too! (Plus, reducing your body's demand for O2 will help ensure that you are breathing normally!)
- Focus on your dive - that's why you're underwater
Best regards - Ray
Ray Purkis