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Exhale (FRC) Adaptation

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The Exhale Diver

Well-Known Member
Sep 11, 2004
I was just wondering how long it takes everyone to adapt to this style of diving?

I am doing about 25% of my diving on exhale 75% inhale, my diving is specifically for spearfishing, most of the reefs we hunt are 15 - 25 metres, although I can only go to about 10 - 12 metres on exhale at this stage otherwise it feels too tight. I have improved slowly from feeling too tight around the 7 - 8 metre mark but its taking a while, having said that I have improved on it doing some dives to 12 metres for 1:45 so its a start, but its hard because I am usually in deeper water than that and all the fish are on the bottom so I need to inhale to get to them.

Anyway if anyone has made the switch to this diving I would like to know how long it took them to feel comfortable at depth, I suppose it depends on how often you get in the ocean currently I am diving at sea 1 or 2 times a week.
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Hi Brett,

I have the impression that you sometimes use exhale dives when you are spearfishing. Hopefully I am wrong because that is not the way to go! If you go spearfishing you should always dive with full lungs!
Exhale diving is a great training tool for deep freediving but in my opinion it is far easier to get a BO. Spearfishing is not competitive freediving, you need all the air you have if you are struggling with a fish. And with air you can stay down longer anyway, which is what is important with spearfishing.
Be careful and maybe cu in Brisbane.
Brett, maybe you can take just alittle more air down with you if that's your limiting factor? for some people exhale diving is done with 3 liters (total) and for others it's even 5 (I think I heard that's about what Seb takes down).

And Haaico, I think you are wrong. Maybe true for most poeople in most circumstances. But FRC diving CAN become the only style one dives also for spearfishing. I know a very qualified freediver/spearfisher who spearfishes in many circumstances with 2/3 lungful (which might not be FRC but it's definitly not all the air one could take down) and Seb Murat claimed it's usable for spearfishing as well if I remember correct.
Also I think I heard Pelizzari doesn't always fill his lungs for spearfishing.

edited for mispellings.
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I'd say for spearfishing dive on full lungs--maybe with packing, maybe without packing... the concept of saving energy on the descent only works if no energy is to be spent fighting fish...
i always diving with a little breath.i never fill my lung and never done up to today.. Because i feel myself comfortable and relax at this condition.if i go 15-20 i keep a little breath in my mouth so as to use open my e-tubes.The tricks is(as for me) to be relax as much as we can..after 5-6 meters starting freefall
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WHY would you even want to do an exhale dive? you can stay down longer when you have full lungs and go deeper, right?

Thanks Chris
Thanks for the input but I didn't really want to start that same debate over exhale diving again, I am more interested on how long it takes to adapt to the depth as this is my limiting factor at the moment (i.e the feeling in my chest).

Also in terms of spearfishing I almost never fight fish anyway, not required they fight themselves. If you consider that I have shot fish twice my size, if I tried to fight them I would be dead anyway.

Chris I actually have dived longer now on exhale than inhale, which I find quite interesting although not as deep obviously as I have not adapted yet and If you must know I am trialing the concept because I am sick and tired of surfacing on inhale dives with a dizzy head, I have not felt that on my exhale dives and furthermore with a shorter recovery I can dive more in a day which should equal more fish. Hope I have explained myself a little more.

Getting back to the question can anyone tell me how long it takes to adapt?

Adapting is a very personal thing, I don't think anyone can say how long it is going to take you to adapt. The main thing is to take it easy and not to push yourself too much.
On the concept of exhale diving (to just clarify my position) I think it depends on how much you exhale before you dive. If I train for depth I tend to exhale to FRC. But if you do not dive to your maximum depth (ie spearfishing) I can imagine not filling your lungs to bursting. That might feel more comfortable. In my case a full inhale doesn't feel uncomfortable so I don't do exhale diving while freediving for fun. But if you are careful I suppose there is no reason not to freedive/spearfish while not completely filling your lungs.
Yeah Haaico I think you may be right about the time, I will keep at it and try to dive often and see how it goes. I like the idea of having the option of both anyway.

Regarding the amount of the FRC, do you think it is consistent how much you hold in or does it vary because I am not sure if I am exhaling the same amount each time.
Brett, the diffucult thing about exhale diving/statics is that it is next to impossible to make sure that you are exhaling the same amount of air each time. That's probably why there are no competitions in empty lung statics!
Just experiment with it. But do not exhale too much otherwise your depth will be severely limited because you don't have enough air to compensate.

I don't agree and find that my FRC dive volumes are more consistent than my inhale dive volumes. If you forget about how much to exhale and just relax to FRC after a big breath in you will find that the volume you are left with is fairly consistent. Also given that Brett started the thread talking about 15-25m bout diving I don't see any issue with compensating. Eric F does FRC to 50m Seb has been to 100m so the rest of us mere mortals can cope with less than 30m with a little training.

Adaptation is an individual process, and is hard to say how long, but you can train your diaphragm and rib cage for more flexibility and reduce your lungs residual volume... this should help with the uncomfortable feeling at depth.

Seb do clinics... It may be the fastest way!

A few points if I may:

You can 'exhale' diving for spearfishing (active) but there are some important considerations which require the diver to minimize activity, especially during the descent and, subsequently, move across and then up with a 'stroke-and-glide' technique.

The workshop which I had the pleasure of running last weekend clearly indicated to just about everyone participating that dive duration on 'exhale' was essentially similar to their ability on 'inhale' and, moreover, after just two days experience. I expect the same thing this upcoming weekend, just like in every previous clinic.

To answer Brett's question about the rate of adaptation there are a few things to consider.

Firstly, to be able to tolerate the large negative lung pressures it is fundamentally important to realize that it does take time. Similarly, one can't be expected to climb, say, Mt. Everest, without prior and long-term acclimatization. Failure to appreciate this will in all probability result in a 'lung squeeze' with pulmonary oedema and haemoptysis (bleeding). This in itself can result in serious health complications and even death.

So, is a 10-20m dive on 'exhale' deep? It's all relative, but if you compare what has been achieved on 'inhale' the answer is... not really. 10-20m is, for example, approximately equivalent to diving between 30m and 50m; both of which can be achieved comportably and without lung squeeze with practice. Nevertheless, many divers have experienced problems even at such relatively shallow depths.

Recalling way back then, it probably took me about a year of constant and consistant practice, in digestible sized pieces, to be able to reach the stage whereby I essentially no longer felt any pressure on the chest, irrespective of how deep I dove. One can understand this if one considers Boyle's exponential pressure-volume law. For our purpose, what it implies is that volume changes, and hence the feeling of pressure on the chest, become effectively quite small as one dives deeper.

Why some of bleed whilst others do not is easily explainable. As some of you may know the pulmonary capillaries are quite compliant to distension, as they become engorged the deeper one dive. Further increases in ambient (water) pressure may lead to intolerable pressure difference across the alveolar-capillary membrane, resulting in trauma as stress failure occurs. Typically, when large convective forces (cardiac output) are required to supply oxygen to the working muscles it is advantageous to have a very thin alveolar-capillary membrane for efficient gas-exchange. It is therefore, not a surprise to hear that race horses which have some of the highest aerobic scopes (VO2max) frequently bleed after racing. The bottom line is that although an elevated scope for aerobic exercise permits efficient gas-exchange it is also associated with thin and fragile alveolar-capillary mebrane walls. What this means is that there is, unfortunately, a decreased tolerance of the membrane wall to elevated pressures. This effect is magnified with exercise in cold and elevated ambient pressures, e.g., swimming to depth. The consumption of excessive amount of water befroe diving or aspirin will also potentiate this problem.

Can lung re-modelling occur such that the alveolar-capillary mebrane walls become reinforced (thicker?) and so that one may perhaps be better able to tolearte large hydrostatic pressures? According to researchers, and I refer you to West et al, repeated stress can and will invoke such changes. In my own case, we have found that as I've become able to tolerate greater and greater pressures my VO2 max has, for example, correspondingly decreased. This is not a real surprise as deep diving mammals have an aerobic scope about a third of those of similar sized terrestrial mammals. What this means is that improving your VO2max is not necessarilly associated with improved pressure tolerance. I would suggest, it's actually a disadvantage for exhale diving. Of course this is not to say that improved pressure tolerance works against the ability to undertake frequent diving bouts (serial diving).

Apologies for the long-winded discourse.

From sunny Perth
hey seb, im booked into your next course on the weekend :wave

how did last weekends course go?
Thanks seb,
That is good explation
''Can lung re-modelling occur such that the alveolar-capillary mebrane walls become reinforced (thicker?) and so that one may perhaps be better able to tolearte large hydrostatic pressures''
as you mentioned above i would like add a few things.As you know hemoglobin and myglobin ratio is different human by human.Transfering 02 to the cells making by hemoglobin and myglobin is storing the 02 transfered by hemoglobin.i belive that if the hemoglobin ratio is a little bit a lot than others as you mentioned above O2 transfer wil be more efectively from alveolar-capillary mebrane .
my statics 2 min and my dinamik is almost close to my statics i think
when i go to 15 or 20 meters from surface to deep and to the surface again 1.15 max
i never felt any pressure on my body up to now.when i am 15 or 20 i fell myself more relaxed.
Thanks for asking the workshop went well.

True, with an increased haematorcit diffusing capacity (gas-exchange) will be enhanced. Nevertheless, oxygen convective capacity will be less because of increased viscosity. In fact, elite (breathing) athletes have haematocrits below average whichh helps move oxygen around a little better. Mind you, they also have higher blood volumes to help out.

It seems to be such a fine balancing act. Sebastien, is your Mallorca course still "on course"?


As much as I'd like to, its likely that I'll have to cut-back as Micki and I are about to welcome our first new born. What this means is that only a few clinics will be running this summer. The one is Sweden, in conjunction wth Sebastien Naslund, will most likely be runnng as I have prior engagements there already. That aside, I will also be in southern France possibly doing some filming as part of a doco with Discovery in late August but not in Nice or as part of the world champs. Its anticipated that I'll be doing some deep unassisted exhale dives and also some 'no-limits' .... at least that's the plan for now. Depending on interest I may also run a 3 day clinic from 'La Cavaliere', which is between St. Tropez and Toulon.

Dear Sebastien Murat,
I have been interested to your new era to freedivingstyle.Although FRC or exhale diving are totally different from inhale diving I want to ask to you did you tried full ihale diving if so what is the results??
And I also want to know is there any fibrotic changes in the lungs of the exhale divers??
And at last are you planning a course in Türkiye in the future , cause I will be the first participant.
Sincerely yours
Dear Dr. Aydin,

In response to your queries:

- I no longer practice 'inhale' diving, for several years now and because of the obvious safety concerns. Neverthless, I use to practice/perform with this technique before then. In my particular case, I can tell you that I now dive deeper on 'exhale' without fins that on 'inhale' by about 7m. I consider that to be significant as my pb with 'exhale' is now 72m (3'20"). I cannot make such a claim, however, for the use of fins as I no longer practice with them.

-There is no direct evidence of "fibriotic" changes, there is only indirect evidence from studies on pulmonary capillary stress failure done on non-divers. I'm currently in Perth (a long way from home) and don't have the references which you may wish to track down. I'll be home next week and will email you these if you so wish.

-Turkey .... Ah! a diver's paradise. Without sufficient numbers (12) I unfortunately can't run a workshop there....sorry. I would say France might be your best bet.

Thanks for your interest.

Sebastien Murat
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