-
Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:
- Join over 44,280+ fellow diving enthusiasts from around the world on this forum
- Participate in and browse from over 516,210+ posts.
- Communicate privately with other divers from around the world.
- Post your own photos or view from 7,441+ user submitted images.
- All this and much more...
You can gain access to all this absolutely free when you register for an account, so sign up today!
A few questions... (Breathing Up Technique and diving environment)
- Thread starterTogaLive
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
Not quite exact, Siku. It would be right in a static system with infinite time in depth/and or infinite elasticity of the chest/diaphragm. In real word there is always some transpulmonary gradient. It is present even on surface (induced by respiratory muscles) - it is what drives breathing: positive gradient >> you exhale; negative gradient >> you inhale.
However rather than transpulmonary pressure gradient, I should have used the term gradient between the external/ambient pressure and the alveolar pressure. Transpulmonary pressure is correctly the difference between the alveolar pressure and the intrapleural pressure in the lungs. Anyway, principally it does not change anything on the claims, and it practically the same. I am telling it just for those who'd like to pick on such details.
So yes, when you dive, the pressure gradient grows, and the pressure gradient is what causes the deformation of the chest and diaphragm, the blood-shift, and even oedema. And yes, at small lung volume (FRC), the resisting limited elasticity of the body will be reached quicker, hence the gradient will grow faster, and the blood shift will be initiated earleir to compensate the pressure difference. And it is in fact a big advantage, because the blood drown away from extremities is still well oxygenated, and instead of being consumed by the muscles, it can supply the brain and heart.
However rather than transpulmonary pressure gradient, I should have used the term gradient between the external/ambient pressure and the alveolar pressure. Transpulmonary pressure is correctly the difference between the alveolar pressure and the intrapleural pressure in the lungs. Anyway, principally it does not change anything on the claims, and it practically the same. I am telling it just for those who'd like to pick on such details.
So yes, when you dive, the pressure gradient grows, and the pressure gradient is what causes the deformation of the chest and diaphragm, the blood-shift, and even oedema. And yes, at small lung volume (FRC), the resisting limited elasticity of the body will be reached quicker, hence the gradient will grow faster, and the blood shift will be initiated earleir to compensate the pressure difference. And it is in fact a big advantage, because the blood drown away from extremities is still well oxygenated, and instead of being consumed by the muscles, it can supply the brain and heart.
Last edited:
Trux, I think this video is of the first record swim in speed apnea, by Cosimo Garofalo:
[ame=http://www.youtube.com/watch?v=wQFHPgf1Bv4]YouTube - record nazionale apnea speed sui 100 mt 42"85[/ame]
which I think is the same event/record you posted on your blog, if I'm correct.
The video doesn't show some of the swim, but does document the breathe-up quite nicely, and I thought it was relevant to the subject of this thread. Perhaps the preparation for the discipline of speed apnea differs dramatically, but that sure seems like a lot of hyperventilation! I believe he did his swim on full lungs also, though it's tricky to see what he is doing there. Looks like he went under to start his swim in mid-yawn actually. I thought it would be interesting to look at from the point of view of this thread.
neuro
[ame=http://www.youtube.com/watch?v=wQFHPgf1Bv4]YouTube - record nazionale apnea speed sui 100 mt 42"85[/ame]
which I think is the same event/record you posted on your blog, if I'm correct.
The video doesn't show some of the swim, but does document the breathe-up quite nicely, and I thought it was relevant to the subject of this thread. Perhaps the preparation for the discipline of speed apnea differs dramatically, but that sure seems like a lot of hyperventilation! I believe he did his swim on full lungs also, though it's tricky to see what he is doing there. Looks like he went under to start his swim in mid-yawn actually. I thought it would be interesting to look at from the point of view of this thread.
neuro
Thanks for the video! Yes, he hyperventilates indeed rather extremely. However, at the sprint it is not too bad - the breath-hold time is very short, the muscles start working immediately in anaerobic mode, not consuming much oxygen, while still producing CO2, hence letting enough for the brain and limiting the possibility of a blackout.