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Peter's excellent Lung Squeeze article

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New Member
Jan 16, 2002
Excellent article on lung squeeze. I know that myself as well as two of my buddies has spat blood after 90' plus dives and we were wondering exactly what the physiological implications were. Luckily only one of us has had the coughing spasms. It would be great to hear other's experiences as well. Great contribution Peter.
Other experiences

Thanks Jim,

I will be forwarding the article to various freediving organizations and freediving "doctors." Hopefully, we'll start getting data on how frequent squeeze happens and the common factors involved. When I send it out, I'll post a list of recipients here. Maybe certain researchers will be tempting to clarify what's known and what isn't.

I'm still learning....

Vancouver, BC
Gathering Data


One thing that I took away from your article was that the root cause of a traumatic descent is still a bit of a mystery. Your article described certain precautions that one could take, and it certainly seemed that these precautions reduce risk to some extent. However, it seemed that you still had an "undeserved hit", despite the precations.

I dive with Jim and most of the guys in our group have loggers (D3s, Mosquitos etc.) I wonder if there would be any value to submitting these logs in the event of a hit -- kind of like DAN's efforts to gather dive log data for victims of DCS -- which raises the question of where we could send any such data ...
Hi Peter,

I have read your „Fear the Squeeze” with a great interest. That is something I was looking for, for a long time.

I have also had an experience with lung squeeze. I do not dive deep, so it happened to me once only (in 2002), after my one and only dive to 40 meters. It was not as severe as in your case. I was spitting blood for about half an hour, couldn’t take a full breath and felt fatigue to the end of the day. A couple of days later I dived again and in this case I was spitting very small amount of blood even after much shallower dives /25 – 27 meters/. This experience has frightened me, as even though I was aware of the danger of lung squeeze, I did not expect it might happen before reaching 50-m. mark.
Then I began to look for information on the subject, but couldn’t find almost anything until I found your „Fear the Squeeze”. Great text. Congratulations.

I wonder if you could give more detailed information about your daily thoracic stretching regimen? After my personal experience with lung squeeze I start to do some diaphragm exercises: I exhale fully, then do a couple of reverse packs, and then suck my stomach into the chest cavity (I am sure everybody knows this kind of exercise). I hope this will help to prevent lung squeeze by increasing flexibility of diaphragm, but I am not quite sure about it. I also do not know how to do this exercise correctly.

Could you tell, what do you think about this exercise, what is the correct way of doing it or suggest any other kind of exercises?

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Just to let everyone know, I sent an email to the AIDA board and the AIDA medic for the Cyprus competition, asking them to read the article and if they would keep track of "lung injuries" at the competition. I also asked that some sort of communication to National AIDA chapters be done (ideally from AIDA International). Otherwise, I'll just forward them a link to my article.

As for my stretching regimen, Nitas, it is something like this:

(morning and night and before diving)
-warm-up (yoga or a 10 min swim)

Then, I do 3 to 5 cycles of the routine below:

-arm circles and swings (dynamic stretch)
-shoulder, tricep, lat, pectoral and back stretches (static)
-yoga type stretches (cobra, downward dog, etc)
-pack stretches (increase on each cycle to a max of 40 packs: 20, 25, 30, 35, 40 I use big gulps!),
-each pack stretch goes slowly with pauses to let the tissues and muscles relax at 10, 15, 20, 25 etc... a hold at the end (no pain)...and then exhaling over at least 30sec to prevent a rapid change in the pressures on the heart and circulatory system. (I do it lying down to prevent hurting myself in case of blackout
-then exhales with reverse packing, 0,5,10,12,15 reverse packs after full exhale, pause at "bottom" and slow inhale

And then diving....

Over two weeks, when I first started, this routine produced significant results. At the start, a full exhale dive to 6m was almost painful, after two weeks, my limit was equalizing beyond 10m on a full exhale.

Always be careful NEVER to push any part of the stretch and especially the pack stretches to extreme discomfort or pain. It is possible to injury yourself doing them, not to mention the strain on the circulatory system. Also I know someone who blacked out and fell down and hurt his back.

Vancouver, BC
add-on to stretching:

i usually (after general warm-up) do upper body stretches with full inhale and mild packing in similar ways peter described.
one exercise i particularly enjoy is rotating the shoulders forwards/backwards very slowly.

i stretch in a sitting position. falling over on the occasional samba (after packing) is less problematic then.

i don't pack stretch very much since i don't dive with lots of packing.

i also do empty lung dives regularly for a year now. in the beginning my depth was limited by my chest/diaphragm flexibility, nowadays it's the equalisation. in this year i more than doubled the depth for empties from 5m to +13m. not as quick an improvement as peter's but i'm not in a hurry and i've never spat blood on any diving activity.

all that stretching is what i really benefit from. i give it a higher priority than increasing lungvolume for example.

peter's article goes along my own observation of freedivers i meet. most of them suffered from lung squeeze at one time or another. usually they do their deep training on a weekend or on a 1 week holiday and they feel like they have to go for it.
i'm lucky personally, since i have the opportunity to dive every day if i feel like it (i usually do:D ), but i feel even luckier to dive unhurt.
there is always another day to dive.

take it easy, guys



Weekend warrior

Immerlustig, you have an excellent point about water access. In Vancouver, we mostly dive on the weekends, so for anyone training for a competition it increases the risk of injury.

Diving three or four times a week (or daily) would be ideal. I'm working on that kind of lifestyle for myself...... Do you know anyone who would like

In Europe, I've heard that there are freedivers who have no access to deep/warm water and then depend on a single week-long vacation to add 20-40m to their pbs. :duh


Vancouver, BC
Hi Peter and Roland,

Thank you for the descriptions of your exercises. It turned out that I had been doing some of them already. Now I’m going to start do the others.

I am still thinking about the exercise I described in my post. A couple of weeks ago I asked Herbert Nitsch about it and now you – Peter, but none of you answered this specific question. Is there anything stupid in it ? On the other hand I know that Umberto Pelizzari does it (maybe I should say he does some similar exercise), so I think there must be a reason for doing it. Is it possible that this reason has nothing to do with protection against lung squeeze? Hard to believe for me, but maybe I’m wrong.

Piaseczno, Poland

I am one of those European weekend warriors with 300 km to the nearest deep lake. Maybe that is why I have a problem with lung squeeze.
uddiyana bandha

Hi Nitas,
In yoga the excercise you refer to is called uddiyana bandha. Here are some links and explanations on how to do it, whith what's probably the best link first.





A little hint: when you do it, you'll probably find it easier to emptly the lungs if, when your hands are on your thighs (near the knees), you tilt your head down so your chin is touching your chest. Then exhale all you can and after that - while holding your breath - suck in your stomach as much as you can. Hold for a while, at least 15 - 20 seconds or what's comfortable. It's a great asana! One of my favorites. There are several variations on this as well.

Hi Adrian,

Thanks for the links. I do this exercise in a little bit other way than uddiyana bandha. I do not do it in standing position, but sitting on my feet with my knees about 0,5 m one from the other. After exhaling I always try to continue in the way Umberto P. does it i.e. I put the central part of my belly out while the both sides (left and right) are still sucked in. I am not sure if it is clear (my English is not fluent), but I hope you guess what I mean.

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