full exhale in pool to adjust to real depth

[tim.h]

Its 3+ hour drive for depth around Melbourne so I've haven't been yet. Before I do though, I want to make sure that I'm as adjusted as I can be. The club is talking about a weekend trip to a sinkhole in South Aus soon.

On the 2nd day of my SSI 1, I got (trachea?) squeezed after going to 23m a bunch of times. At least, that's what I inferred.* I did some full exhale statics at the bottom of a 3m pool - lying down and full exhale at the bottom of the pool (lower RV than at the surface). When I cleaned my teeth that night, I spat up a tiny amount of old blood, just like the other time.

I train at a pool with depths of ~2.5m, 3m and 5m.

So a couple questions:
- it was squeeze, right?
- is there at way to compare/calculate an equivalent depth - full exhale vs. full inhale so I can know what my safe depth is?
- how can I use exhale dives to train for depth?

 

[baiyoke]

This is a really serious subject, so take everything I write with caution... Others might have other opinions...

In general I think you should skip the idea of doing exhales... There's no point, since you are not going to a specific depth, and even if you got a bit more flexible, you will just meet your limit a bit further down... same same... However, you can do a lot to prepare yourself, mostly when it comes to technique and the mental part (it's all one blend in freediving).

About the squeeze: I can't say what/where it was. Could be from sinus also. If it was trachea or lung squeeze most likely it had to do with you doing some odd movements, one way or another: Not keeping you chin down to chest (fx looking "up" at the bottomweight or surface), arching your back, pulling to high on the rope, being tense or other things... In general train the things you learned at the course, and have someone observe and give feedback, it can be difficult to correct yourself. Make a list of things to remember and work on, and have your buddy observe...

So instead of starting very advanced tecniques, go back to basic, train, repeat...!

I did some full exhale statics at the bottom of a 3m pool - lying down and full exhale at the bottom of the pool (lower RV than at the surface).
?

No, RV is theoretically the same at all depths, as far as I can tell. You got pressure on your belly, but so does the gas in your lungs. RV is a mechanical limit. That's the short answer anyway. Don't know if there's some practical changes that applies, but the surrounding pressure doesn't theoretically change your RV or make it easier to get to it if exhaling at depth.

But if you exhale on the surface, you can quickly simulate very deep dives. I do not recommend you start that now, especially since you allready might have a squeeze one time, and might be prone to another one because of tissue damage/weakening after the first one...

One thing you need to understand is, that if you exhale completely at surface and dive, you allready start your dive at RV, or the equivalent of 25-35m! And the speed of change is much faster. So for the average person (TLC 6 L, RV 1,6 L), a full exhale at surface + drop to 5 meter (1,5 atm), would simulate a full lung dive to 50 meters in a few seconds!! 6TLC / (RV1,6 *1/1,5) = 6 atm = 50m.

Anyway, be very carefull about exhale dives, you can black out more easily. And get squeezed.

- is there at way to compare/calculate an equivalent depth - full exhale vs. full inhale

Theoreticaly yes, but you would need to know your total lung capacity and your RV (and how much you exhale if only partial) to get it right. It can be estimated roughly, but I recommend you to train basics instead, duck dives, body position, equalization etc...

so I can know what my safe depth is?

You can't. There's no safe depth. Too many factors to include, especially your technique.

 

[Siku]

baiyoke's answer look really good to me.

I just wanted to reinforce that if you get squeezed once you are more likely to sufer squeeze again. So pushing too hard in training could SERIOUSLY inhibit your ability to dive depth. There are lots of guys who are resticted now due to squeezes. Don't push it.

If you're getting squeezed you're diving wrong.

 

[tim.h]

Amazing answer, baiyoke!! Really appreciate the time you took to write a reply.

Not keeping you chin down to chest (fx looking "up" at the bottomweight or surface), arching your back, pulling to high on the rope, being tense or other things... In general train the things you learned at the course, and have someone observe and give feedback, it can be difficult to correct yourself. Make a list of things to remember and work on, and have your buddy observe...

So instead of starting very advanced tecniques, go back to basic, train, repeat...!

This. I remember being told this on Day 2 but improved it from the next dive. It makes sense though - I would have been lying on my stomach looking along the bottom of the pool.

No, RV is theoretically the same at all depths, as far as I can tell. You got pressure on your belly, but so does the gas in your lungs. RV is a mechanical limit. That's the short answer anyway. Don't know if there's some practical changes that applies, but the surrounding pressure doesn't theoretically change your RV or make it easier to get to it if exhaling at depth.

Yes, you're right it should be the same. I'm sure I felt like I could exhale more at the bottom. I suppose I could have been in a better position to exhale.
[/QUOTE]

One thing you need to understand is, that if you exhale completely at surface and dive, you allready start your dive at RV, or the equivalent of 25-35m! And the speed of change is much faster. So for the average person (TLC 6 L, RV 1,6 L), a full exhale at surface + drop to 5 meter (1,5 atm), would simulate a full lung dive to 50 meters in a few seconds!! 6TLC / (RV1,6 *1/1,5) = 6 atm = 50m.

Understood. I can see how that could be quite dangerous.

Theoreticaly yes, but you would need to know your total lung capacity and your RV (and how much you exhale if only partial) to get it right. It can be estimated roughly, but I recommend you to train basics instead, duck dives, body position, equalization etc...

You can't. There's no safe depth. Too many factors to include, especially your technique.

Fair enough.

baiyoke's answer look really good to me.

I just wanted to reinforce that if you get squeezed once you are more likely to sufer squeeze again. So pushing too hard in training could SERIOUSLY inhibit your ability to dive depth. There are lots of guys who are resticted now due to squeezes. Don't push it.

If you're getting squeezed you're diving wrong.

I suppose so. Not much chance of going too hard if I'm only going to the pool once per week, but the extra conditioning makes it easier to do something silly at depth.

I'll do what you suggested. Practise the basics, body position in particular.

 

[Kars]

I think you got squeezed because:

- you were tense
- you did some bad moves
- you did not allow your body time to adapt to depth
- you do not have a good equalisation technique, causing forced bad moves.

The special thing about freediving is: applying more force is counter-productive.

What freedivers need is: relaxation, flexibility, technique, time.

What you can do in preparation for a deep dive session:

- learn to do long and slow dynamics, normal breath and frc.
- learn to have a nice static.
- learn to get into the 'dive-mode' (mental state) fast without long breath-ups.
- become more flexible, especially in the upper body. (diaphragm, ribcage, neck, shoulders, equalisation muscles)
- learn to equalise frenzel-fattah well, in any position, using small amounts of air.


In all it appears to me that you're trying to go too fast in general, skipping the basics.
Use your eagerness to learn techniques, not for rushing for another pb.

Since your deepdive session is 3 hours away, maybe you can stay over for a night and turn it onto a weekend? And if it's a weekend, you may want to drive the night before.

Learning to get into dive mode quickly is gold, it means less time above preparing. I find newbee's often spending 2-4 minutes for a dive to 12m, which takes them 40 seconds at most to do. It's a sign of uncertainty, in preparation to doing a record. My advice is simple, do 3 slow motion inhales, and dive in slow motion, focussing on doing equalisations and relaxations in between. When you feel getting tense, stop, turn head up and take time to relax and get comfortable at that depth by doing a little static hang at that depth. Get as comfortable and just as relaxed as you were doing a static at the surface. Gently pull to the surface. Enjoy the first inhale and slow long dives.
Have plenty of slow and long dives, focus on relaxation and technique and slow movements.

Have the line and plate set up deep, out of sight, so do don't have the temptation to make it to a certain depth.

Don't wear a dive computer, you're focussed on learning, not on pb's.

You're experienced trainer will be at your side and he for sure can tell you how it went. At the end of the day you can wear a dive computer doing another (now easy routine!) dive along the line, to see what your new comfort depth is.


On exhale dives, these are indeed for advanced only. A forced empty dive to -5m is likely to reflect a -50m dive. I think its logical one must spends an equal amount of divetime doing the forced exhale 5m: 2 minutes. (50s down - 20 static - 50s up) This all without contractions, with an easy Frenzel-Fattah.


Take your time, relax and go slow.
It's not the number that makes a dive great.


Love, Courage and Water,

kars

 

[growingupninja]

Kars has very good advice--especially about diving slow and relaxed, with focus purely on the moment as opposed to time or depth. Forced exhale is very good training but remember on a forced exhale dive/neg pack dive that while you may be simulating the chest compression of a very deep dive, you have a FRACTION of the air, so hold/bottom times should be adjusted accordingly.

In other words, if you are diving full lung to 50m, even when your lungs are at or below RV at depth, you still have the full lung's worth of O2 which you started at surface with, which--assuming a trained diver with a good size lung capacity and healthy dive response--is good for minutes of relaxed bottom and transit time. But if you do a forced exhale, you have maybe 25% or less air in the lung when you start the dive, so you will start with a MUCH REDUCED safety margin, and should adjust the dive time accordingly....

Wet, forced exhale work is advanced training. I would spend time doing dry exhale holds, with and without exertion using an O2 sat meter to see how the exhale effects your limits before training forced exhale in a pool or ocean.

 

[baiyoke]

In other words, if you are diving full lung to 50m, even when your lungs are at or below RV at depth, you still have the full lung's worth of O2 which you started at surface with, which--assuming a trained diver with a good size lung capacity and healthy dive response--is good for minutes of relaxed bottom and transit time. But if you do a forced exhale, you have maybe 25% or less air in the lung when you start the dive, so you will start with a MUCH REDUCED safety margin, and should adjust the dive time accordingly....

I agree that caution is very advicable. And BO risk is bigger.

But a word about the amount of air in a more general exhale discussion: It's true that the amount of AIR is reduced to (perhaps) 25% or even less. But to even the factors out
- the distance/time you travel is much shorter...
- the amount of OXYGEN is probably limited from 100% to (somewhere about) 62,5 % (50 in bloodsteam/tissue + 12,5 (25%) in lungs).

Just saying.

But most importantl to remember is to be cautious about BO yes.

 

[Mullins]

If you're getting squeezed you're diving wrong.

Possibly, but there are plenty of people who get squeezed no matter how careful they are.

 

[esom]

Possibly, but there are plenty of people who get squeezed no matter how careful they are.

being careful can be close to being doubtful or slightly alert in this context. these states are producing squeezes to my experience. So squeezes can happen although and because someone is careful.