Never Ever Hold Your Breath But......

[MauiScubaSteve]

You can practise good breathing technique on the surface: Breathe in from the bottom of your lungs. Hold (Use). Breathe out at a ratio of 1:3:2 ie: breathe in for 3 seconds, hold (use) for 9 seconds, exhale slowly for 6 seconds.

:no Did you learn this from a dive scientist, dive instructor or even a humus breathed dive guru? This is skip breathing, and doing this underwater could result in unconsciousness. Why would you practice breathing for diving in a way that can be fatal if you do it while diving?

 

[ietermagog]

I learnt this from a world record holding constant weight freediver who is also a scuba instructor. Myself, I am a scuba instructor and amateur freediver with a few thousand scuba dives and have taught many students and re-taught many more certified divers who come brandishing their tickets but still can't master a fart underwater let alone their breathing or buoyancy.
The breathing exercises I described that you practise on the surface train your body to utilise the air you breathe efficiently. I have found the discipline of freediving training to be most useful to nervous scuba divers - who learn the most important skill in diving - to be comfortable in the water and not fight ones body. Quite clearly the aim is not to kill anyone. I have got people to halve their air consumption and their weights needed just with proper breathing techniques. Obviously it is easier to do and supervise in person than online, where what is said can clearly be misconstrued. This is why I did not mention any of the other tips and techniques we use which happen in the water.

In my opinion the mantra "Breathe continuously and never, ever hold your breath" is the cause of the majority of students breathing incorrectly -because they are petrified of accidently holding their breath they tend to breathe in and out too much - continuously as opposed to regularly. Try saying slowly "Breathe in. Use your breath. Breathe out."

Excuse me now, I'm taking my humus breathe off to dive.

 

[Rick Murchison]

Buoyancy control and good breathing technique go hand-in-glove. Here's a little blurb I drag out about once a year...
Rick

Buoyancy Basics
© 2002 G.R. Murchison, CDR USN(Ret); SSI DCSI

You recall from open water training that buoyancy is determined by the relationship of the weight of an object to the weight of the water it displaces when it is submerged. If more water is displaced than the object weighs, it will be positively buoyant and will rise or float; if less water is displaced than the object weighs the object will sink. As Scuba Divers we generally seek to achieve that balanced state where we displace the same weight of water as our own weight – neutral buoyancy. This is easy to understand, but not so easy to achieve. Let’s take a little closer look at neutral buoyancy and why it is so elusive.

Neutral Buoyancy isn’t!

Theoretically, all we need do to achieve neutral buoyancy is to get our weight equal to the water we displace – simple… and impossible!

(1) We cannot get our weight exactly right because (at least on open circuit Scuba) the amount of water we displace is always changing, because we’re breathing. As we inhale we increase our volume, displacing more water. Since our weight remains the same we become more buoyant; likewise we become less buoyant when we exhale.
(2) Neutral buoyancy is an unstable state. Even if we were to stop breathing (don’t!), neutral buoyancy would be fleeting. Let’s assume we could actually get perfectly neutral for a moment. So long as we and the water are perfectly still and static we’re fine, but any displacement will upset the balance. If we are displaced upwards, the air in the flexible parts of our system (BC bladder, CCR counterlung, exposure suit) and in our body cavities will expand, and we will become positively buoyant, thus tending to continue upwards. And as we continue upwards those gases will continue to expand and we will get ever more positively buoyant, until we reach the surface or something ruptures. Likewise if we are displaced downward the gasses in the system and body will be compressed; we will become less buoyant and we will sink at an ever increasing rate until we reach the bottom.


Controlling instability

Much like balancing a stick vertically on a finger, maintaining neutral buoyancy requires constant adjustments. (And, much like balancing a stick vertically on a finger, when you first start you can expect a lot of movement, but with practice you’ll get to where your adjustments are so smooth and tiny that they are “still” to the casual observer, and all but unconscious to you.)
First, let’s consider the options of the closed circuit rebreather (CCR) diver. Since the CCR diver inhales and exhales into a counterlung, there is no net change in volume – and so no change in buoyancy – due to simply breathing. Therefore the CCR diver must counter any vertical displacement with fin action rather than breathing. This is both a blessing and a curse, for while breathing doesn’t start the CCR diver on an ascent or descent, neither can it be used to start or stop one when desired.
In open circuit (OC) Scuba we have the additional change in buoyancy as we breathe to deal with as well as the natural instability of neutral buoyancy itself. However, the fact that breathing changes our buoyancy can work to our advantage, because if we pay attention to the timing of our breathing it can actually provide most if not all the corrective force to keep us at constant depth in the water. Let’s examine the dynamics of a displacement from neutral to see how to use breathing for fine tuning buoyancy control. As a starting point, let’s assume we have achieved perfect neutral buoyancy with half a breath in our lungs. If we are displaced upwards, we will rise until we provide a counterforce to stop the rise. So, we begin to exhale as we start upward, and continue to exhale until our upward movement has stopped. Remembering that an object in motion will remain in motion until a force in the opposite direction is applied, we must have exhaled enough to have applied a downward force – we have become negatively buoyant - to get our ascent to stop, and so if we do nothing at this point we will begin to sink. And as we sink gasses in our body and BC will compress and we’ll continue to sink unless we do something to counter it – inhale. But this “exhale while rising, inhale while sinking” doesn’t keep us stationary, does it? To achieve near stability, we must get back to neutral as soon as we stop at a desired depth, so it goes something like this… As we are descending we inhale to stop the descent; as we come to a stop, we must immediately exhale to get neutral, because in order to stop the descent we had to get positive. Continuing to exhale, we will eventually become negative again, and need to inhale before a descent can start, then exhale before an ascent can start, and so forth. With a great deal of practice, we will find that we can breathe slowly and deeply without ever making any noticeable vertical excursions at all! Now we are fish!


Using the Buoyancy Compensator

Aside from flotation on the surface, the BC should be used only to compensate for the changes in buoyancy experienced due to exposure suit compression with depth change and gas consumption during the dive. From our discussion of buoyancy above, adding air to a BC to initiate an ascent or removing air to initiate a descent when we are already neutral is totally unnecessary, as any displacement upwards or downwards will continue unless corrected. During ascent it may be necessary to vent some gas from the BC to maintain the rate of ascent we want, and to vent a bit more when reaching a new shallower depth to re-establish neutral. Likewise, during descent we may need to add some gas to maintain the desired rate of descent, and add a bit more when we reach our desired depth to re-establish neutral there.



Proper Weighting

Weighting should take into account the gas to be used during the dive. Since we want to be able to make very precisely controlled ascents, and stop at will for safety and decompression stops in open water without the aid of any down-line or anchor line at the end of the dive, we must carry the weight of the gas we’re going to use at the beginning of the dive to assure we can achieve neutral buoyancy at the end of the dive. Nitrox or air weighs, on average, about .08 pounds per cubic foot. With an Aluminum 80, for example, starting a dive at 3000 psi and ending it at 500 psi, we use 64.5 CF, or about 5 pounds of gas during the dive, and we’ll need to carry that five pounds in extra lead along from the beginning of the dive. In other words, if you are properly weighted (able to sink by exhaling or float at eye level with full lungs and an empty BC) with a full AL80, you need to add 5 pounds to be properly weighted with 500 psi.
Remember that salt water weighs about 102.5% what fresh water does, so we displace about 2.5% more water by weight in salt water what we displace in fresh water. We must therefore compensate at the rate of about 2½ pounds per 100 pounds total weight (our body and all our gear) when we move from one to another. For example, if I am correctly weighted carrying 14 pounds of lead in salt water, and I weigh 240 pounds with all my gear on, for fresh water I would need to remove about 6 pounds, and my proper weighting would be carrying 8 pounds of lead.

Rick

 

[MikeFerrara]

Originally Posted by ietermagog
You can practise good breathing technique on the surface: Breathe in from the bottom of your lungs. Hold (Use). Breathe out at a ratio of 1:3:2 ie: breathe in for 3 seconds, hold (use) for 9 seconds, exhale slowly for 6 seconds.

:no Did you learn this from a dive scientist, dive instructor or even a humus breathed dive guru? This is skip breathing, and doing this underwater could result in unconsciousness. Why would you practice breathing for diving in a way that can be fatal if you do it while diving?

IANTD describes correct breathing as inhale, pause, exhale, pause. I don't remember the exact ratios they recommend and it's too cold to go out to the garage to dig up a boook. LOL

 

[Trixxie]

Skip breathing can also cause headaches while diving due to the increased CO2 buildup.

a person I dive with used to always come up with a headache, after discussion we came to the conclusion that they were skip breathing so conserve air.

I think skip breathing is almost like holding your breath rather than just a pause. Longer than a short pause between inhaling and exhaling.

 

[MauiScubaSteve]

If the definition of skip breathing is to skip a breath, then I consider 1:3:2 ratios to be skip breathing, especially 3:9:6. I'm good with a pause but holding (using?) for the same amount of time as both in and ex-haling together seems to me exactly the same as skipping a breath! Do what you want but I will never recommend holding (using), and have seen no reason to after teaching breathing control as stated in my previous posts.

I will take a longer look at Rick's post after today's dives.

 

[islamorada]

The reason that divers are told never to hold there breath, is that in an assent, all gasses expand, even the ones allready in your lungs. Holding your breath restricts the air movement out of your lungs, and in doing so you risk a ruptured lung.

 

[Slaveeye]

By properly weighting and using good breathing control can help with gas consumption as you have read here. But I'd like to add something else.

Some regs are set so sensitive for effortlessly breathing that when a diver is in the horizontal position some regs might tend to free flow slightly (not a full on free flow but a slight one) and if your lips are not firmly sealed(not to be mistaken for clenching or stiff lipping, just sealed) around the mouth piece then air will be wasted by leaking out and not being used for inhalation. My GF had this happening and when I brought it to her attention here gas consumption improved dramatically.

Just another suggestion.

 

[Slaveeye]

Oh and please for your safety never ever ever HOLD YOUR BREATHE!

 

[fisherdvm]

I hold my breath all the times! But only for clearing my ears, and on the way DOWN. I think people who say they "hold" their breath, implies a very slow inhalation at the maximal lung capacity, followed by a very slow exhalation, at the end of their breath. Or to inhale very slowly, at the end of a maximal exhalation, followed by a very small shallow insiratory and expiratory effort to maintain low lung volume.

Using these techniques, one can glide in and out of holes, and safely "fly" over underwater obstacles.