Holding your breath while ascending

[Gombessa]

I am basing this on the fact that when most people take a breath and hold it they are not closing the airway off they are just keeping their diaphragm pulled down thus creating a larger volume of air in the lungs and keeping it there until the diaphragm is released.

At least for me, this isn't true at all. If I take a deep breath and hold it (mouth open or closed), I instinctively close my airway. This lets me release the pressure from my diaphragm so I'm not constantly "flexing" it - it just relaxes in a flexed position against the greater volume of air in my lungs. It actually takes quite a bit of effort to take a deep breath and keep that volume steady by holding your diaphragm down.

 

[claymore]

I think what the OPs asking(just for the sake of asking as i don't think he wants to know if he can hold his breath) is if your ascending wouldn't the increased volume make you let it escape or in other words you would feel the pressure and exhale or you'd have to actually try to hold it in.

If this is not what he's asking.... nevermind

That is what I was asking. It is as much a question of the different physiology's of holding your breath as it is would it work.

 

[rstofer]

If this unintentional holding of breath during ascent was a problem, we would have divers dropping like flies. And we don't. It just isn't a problem.

I have read (on the Internet so don't placed much credence in it) that looking up while ascending may cause the airway to close off. Again, almost everyone looks up while ascending. It's part of the training to extend one arm upward as you surface. You really don't want to surface through that colony of jellyfish, do you? Once again, this just can't be a problem. We aren't losing that many divers.

Just breathe normally and everything will be fine.

Richard

 

[SkipperJohn]

I am basing this on the fact that when most people take a breath and hold it they are not closing the airway off they are just keeping their diaphragm pulled down thus creating a larger volume of air in the lungs and keeping it there until the diaphragm is released. In this scenario the lungs are not sealed and should allow any increase in volume in the lungs to escape out through the mouth.

I think that when most people hold their breath, especially where water is involved, they lock down that g-thing (glottis) TS&M spoke of. I don't know that anyone has the ability to control their diaphragm with enough precision to truly halt all air flow without this.

 

[CamG]

Greetings Claymore and if you put air into a open upside down bottle, etc and then ascend you can watch the air expand. It will exit the opening in bubbles. This is a visual display of expanding gas from a "open" vessel.
Repeat the exercise but after filling the bottle replace the cap. What you will see is a rupture of the bottle allowing the expanding air to escape. This simple illustration made the instructors point very clear. As posted earlier it takes just a few psi to rupture the alveoli then an embolism has occurred. I have repeated the exercise with a zip lock bag as well.
I personally breath normally and try to exhale normally. I have heard, not seen embolisms occur in just several feet of breath holding. I have trained for this type of rescue and it is a very intense, traumatic scene, once you observe it you will never even ponder holding your breath again. I hope this helps but I know this might be a little off the original OP. Just trying to expand a little on the topic.
Safe diving to all and remember the 1st rule "Never ever hold your breath while diving!"
CamG Keep diving....keep training....keep learning!