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Negative (Exhale Dives)

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Oct 8, 2002
I have been trying a few exhale dives to increase my tolerance to the pressure in deep water.

First time i did it i exhaled completely and duckdived. By 4m i felt my chest was going to implode and even my cheeks were being sucked in. It felt really really uncomfortable so i aborted.

I tried again and this time felt a little better at 4m but still quite bad.

On attempt 3 i hit a whopping 5.1 m ;) and managed to stay for 18 seconds :D

Does this get more comfortable or does that feeling of imminent implosion persist.

How deep do you normally do these?

Do you exhale fully at the surface or on your way down?

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I find the same problem - I probably described it on another thread. The sudden change of pressure is far too much for me, and the amount of air I have is only enough for a few seconds! The depth is less than 4m.

I never exhale all the air.
You have to be in Functional Residual Capacity, that is: Take a deep inhale and exhale just relaxing your thorax, not forcefully.

I think this kind of diving is superb for training purposes, because you star with low oxygen from the lungs.

For deep diving you should take it easily. I had problems at 10 when started the practice, now I can reach 25 without that odd feeling in the chest.

This is also very good when you are warming up for a PB in constant ballast
Thanks for the advice Frank.

That will be great training in the pool when you cannot get to deep water.

Will exhaling the full amount not be even better training?

You mean 25m with expired lungs?

Whats more effective for deep water training, negative dives or pack stretching? Both stretch teh ribcage and diamphragm but inversely.


Como esta colombia? Todo bien?

Un abrazo desde Gibraltar :D
Todo muy bien por aca. Gracias

I've found that exhale dives while dynamic training helped me to make big improves, in the last months my dynamic distance increase 15 meters (I was blocked in the 75 meters for 4 years!!!). I'm doing 65 meters in exhale. (Not full exhale)

Also doing exhale dives, this time total exhale with reverse packing at 2.30 meters helped me to improve equalizing skills and also a pain that I felt in the chest when I arrived to 40 meters, two weeks ago in the Colombian National I made it witout any pain.

At this moment all my stretch is with normal lung volumes, but I do believe that full exhale with reverse packing in shallow depths help a lot in thorax flexibility.

I can't go to deep water as often as I want it. But with this kind of training every time I'm in deep water can improve the depht without any problems.

Try it and let me know. Or if U want a more detailed explanation of my training don't hesitate to ask.

Donde aprendiste español?. Parece que lo hablas bien.
Originally posted by shaneshac
That will be great training in the pool when you cannot get to deep water.
Will exhaling the full amount not be even better training?
You mean 25m with expired lungs?
Whats more effective for deep water training, negative dives or pack stretching? Both stretch teh ribcage and diamphragm but inversely.

Shaca, what you want to do is as Frank says: just do a passive exhale at the surface if you want to dive a little deeper. This will slow down the bloodshift as it will take more time to get the chest compression you are looking for.
However, if you have a line (use your fishing float with a few kilos tied to the deep end of the line), you can safely do a 'full exhale' dive. I would recommend that you do a passive dive first to a depth where you feel the compression, then do the full exhale dives after. Do your breathe-up, then exhale, saving air in your mouth to use for equalizing. (see Frenzel-Fattah technique). Dive with your finger and thumb around the line so that you can stop at any time. When you get to your depth, just hang there for a short time to hear your heart rate drop, but come up as soon as any urge tobreath comes. Pull yourself up the line to save 02 and to save your legs for later.
In between every exhale dive, you should do a good 'pack' on the surface to re-expand your lungs. At least once you are ready to do normal dives.
In very shallow water (3 to 8 metres), you can do full exhale dives with reverse packing to get the bloodshift even faster and more shallow. A 5 metre dive can simulate the compression of 50+ metres, so be careful to work your way down and not injure your lungs.
Erik Y.
Thanks for all the advice guys.

i will try both of your suggestions to see what suits best.

By the way, and forgive me for being lazy, what is reverse packing?

Thats what my wife does when i pack all the wrong stuff in the suitcase forthe holidays :D

Frank, aqui en Gibraltar todos hablan ingles y español perfecto. Todos somos bilingues. Somos una colonia Britanico en el sur de España conque tenemos lo mejor de los dos paises.


Reverse packing

Originally posted by shaneshac

Thats what my wife does when i pack all the wrong stuff in the suitcase forthe holidays :D

Reverse packing is the opposite of normal packing - you pack mouthfuls of air out of your lungs to empty them more than normal residual volume.
Hope that explains it, or maybe someone else can add to this.

I never imagine that (bilingual from Gibraltar).

Lucia explained what it is, but maybe you need a more detailed description:
-First, you need to do a full exhale (forcefull exhale) and feel your lungs empty
-Second put your tongue in the upper part of you hard palate and the tip of it just behind your gums.
-Third, with the tongue in that position, move it downwards, you should make a noise similar to "GLUP" and your mouth will get full of air. That's one reverse pack
-Fourth, send that air to your mask, and repeat.

It's better that you start at a shallow depth (2 meters), doing initially 2 full exhale dives, then 2-3 reverse packs, and increase it as you feel comfortable.

When you feel that the tongue maneuver is insufficient to take air from the lungs, use it at same time with a diaphragmatic contraction.

Also you can try reverse pack again, once you are in the bottom of the pool.

Hope I don't need to remember that this has to be done with a watchful partner.

Un abrazo desde Colombia ;)
There always is a question that bothers me and keeps me from doing exhale dives to increase my tolerance to pressure and that is the fear of lung squeeze.

Some math:
Say one reaches his residual volume at around 40 meters. At 40 meters the ambient pressure is 5 bar.
If one would then exhale fully and dive to 10 meters there is an ambient pressure of 2 bar (twice the surface pressure). This would then simulate the lung pressure of an equivalent dive to 2x5=10 bar which is 90 meters.
This example shows that with empty lung dives one can simulate very deep divers very easy. Doing a mouthfill according to the frenzel fattah method could make the simulated dive even a lot deeper. So at 10 meters depth you could simulate an over 90 meters deep dive, which is very deep.
Passive exhales would make the differences smaller but the pressure changes still occur very fast compared to full lung dives.

Therefore my questions are:
How do you avoid putting too much pressure on the lungs and therefore avoid damage?
How do you know how deep you can go safely on empty lungs?
How slow do you descend and ascend when doing this?
How often can you do it?
Hi Roland,
You must put in the equation the blood-shift, humans can go far beyond from the "predicted" Residual Volume. As an example the exhale dives of Murat at 100 meters.

Of course the main danger of this kind of training is the lung squeeze. I never do full exhale beyond 10 meters and my passive Exhale or FRC dives are to 25 meters max.

This needs an slow approach, dephts most increase gradually.

For example (and he will correct me if I'm wrong) Eric Fattah has done around 60 meters in exhale, but around 88-89 in inhale dives.

The speed of descent depends on how well you manage that depht, I sunk very fast in FRC dives to 15 meters because I'm use to it, but to start I recomend you to make feet first, hanged to the line and around 1 meter/2 seconds. You should stop as soon as you feel any disconfort and ascent at a normal rate.
I do FRC trainining 2 times a week, but if I can make more often I'll make it. I think that the main problem is not the frecuency, is the rate or speed of descent, when you are new to the practice.

There are may benefits of exhale dives, do a search on this forum because there is a thread with full discussion about it.

My advice is that you must listen your body, and you will now how deep can you go safely.
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Originally posted by fpernett
Hi Roland,
You must put in the equation the blood-shift, humans can go far beyond from the "predicted" Residual Volume. As an example the exhale dives of Murat at 100 meters.

100 meters exhale :confused: :duh :confused: :duh
And there was i thinking that my ribcage was going to pop at 5m.

Thanks for the info. I will try that reverse packing.

Are there any other pointers ie don't eat a hot curry the night before you try reverse packing. I think that has DISASTER written all over it :D


Thanks Frank,

Thanks for the info. It gives some insight how to do empty lung dives.

I know that without things like bloodshift people would not be able to dive beyond the depth in which they reach residual volume. Diving beyond residual volume increases chances on injuries of which lung squeeze is a fine example. There is a nice article on this among the medical articles called “fear the squeeze”. I do not know if you had a particular thread in mind? Many threads say something about it though but I did not find a thread with info on how to do train it safely. In general these threads do not sound very encouraging because they most have experiences of lung squeeze in them.

I do not like taking risks when freediving and therefore “fear the squeeze” ;) . Seems that no one dares to give some guidelines and claim that following these guidelines will keep you from harm. Almost seems that when doing empty lung dives you simply take a risk. I did not find much more tips than written in the article and what you posted.

Hope someone dares to write a set of extensive guidelines someday as a kind of safety manual for empty lung training.

Wanted to give you karma but it said I have to spread it around more first.
HEy Frank,

Since you offered, some rib cage, pack stretching exercises would be great.

Haces pesca submarina?


I have to spread the Karma too ;)

I'll give you a sample of my stretching routine as a basic I reccomend to follow the David Lee stretching routine.

I added to this routine another chest stretch, standing up, make that your parnter try to put your arms together in your back.

Try to hold the positions for at least 1 minute and 1:30 min for the more stiff muscles.

I do this stretch before any exercise and in some resting days.

After the stretching I made abdominal contractions with full pack (around 3) and then the same but on full exhale (this is like a yoga exercise but don't remember the name). The abdominal contractions is that you must try to move your abdominal muscles toward your spine and thorax (up and backward).

After that I made my training routine for that day, and at the end went to the deeper side of the pool (just 2.30) and made 2 full exhale dives (when I started this I use to make 2 partial exhale dives first) always suck all air from my mask and keep it in the mouth, then 2 exhale dives with 5 reverse packs, 2 with 10 reverse pack and 2 with 15 reverse pack (this is quite difficult), in the last 2 I try to do some diaphragmatic reverse pack but hardly can make one more.
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