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asthma and freediving?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Jan 23, 2004
Hi all--

I'm new to the board, and indeed to freediving as a sport in its own right. However, new to water I am not. I know from experience that I can hold my breath for 4:30 (I used to practice during boring lectures at college!) and I can swim 40m along the bottom of a swimming pool. At the seaside without fins I can pick up shells from about 15m depth.

Thanks largely to the info available here I now understand a little more of the physiology of freediving and how to interpret what my body is telling me. Knowing what I do now, I'm sure I could do better. So I'd like to get involved!

But here's the crunch: I have moderate persistent asthma. It's well controlled and doesn't keep me from excercise - or even scuba diving for that matter. But funny things tend to happen to lungs at great depth and I want to find out if there is any clear medical opinion on this.

Bronchospasm is not personally a problem for me so long as I take the appropriate steroid & beta-agonist inhalers, but I am worried about side effects that might be caused by excessive mucous - which I do suffer from. Do any of you have any experience?

With warmest regards,
My best take on your situation is also the most obvious one- that you get yourself to a respiratory physician that is also conversant with diving and see what he/she has to say.

While asthma is a contraindication to SCUBA diving, freediving also poses it's own set of conditions, most notably stresses induced by the neophyte attempting to better their time/depth. These stresses can often induce the onset of an asthma attack. When you're in the water and this happens, you better have a few things in order- your hand on the weight belt release, your buddy hauling ass to help you, and luck.

Let us know of your findings as I'm sure that you're not alone in your situation. Maybe giving Howard at that other freedive site also in the UK a call for a referal might speed things along.
I too have asthma, though not as bad as yours as I no longer use my inhalers. Though I find that there hasn't been much of a problem with it, though i too have quite a mucous problem that does plague me from time to time, so if you find any way of improving that I'd like to know:).

I just know what my triggers are, stress is one of them, so I take the diving relatively slowly in terms of progression. I try not to over step my limits.

So if you keep to one rule of freediving, it would have to be know oneself! From there you can progress with relative safety. If your feeling tired or wound up then put the target back a bit.

Interesting thread for me this, as I get mild asthma from time to time and have tried to find out more information about any problems with freediving. My asthma is usually bought on by exercise in the cold or household dust (im allergic to cleaning) Interestingly it only occurs in the UK so I wonder if it is also linked to pollutants or cleaning chemicals as well??

I have been spearfishing and freediving for 6 or 7 years now (to quite modest depths) and have not experienced any problems at all. In my case I believe freediving has actually helped my asthma. If i feel some wheeziness coming on the first thing I do now is lie down somewhere and do some focused breathing in much the same way as I would for a static breathold (but without the breatholds). This almost always cures the problem.

In the summer I am in the water three or times a week and find i hardly get asthma at all. This is also the case when I can find the motivation to do regular breathold tables.

Of course the severity of my asthma and its triggers may be completelly different to yours but these are my experinces.

Hope this is useful info.

Thanks for the replies folks. I did talk to my doc about SCUBA, and I learned that the commonly acknowledged risks are twofold-

1) bronchspasm / asthma attack underwater, triggered by the exertion of swimming, overbreathing, the effect of cold water, or the fact that the air is very dry.

2) hyperbaric injury due to air at pressure seeping behind mucous that pools at the base of the lungs, which must then re-expand upon ascent.

Doc thinks that 2) is only a theoretical possibility and not really a problem unless you dive with a steaming chest infection. Seeing as my asthma is well controlled and I can predict and episode of wheeziness a mile off, I've been signed off to do SCUBA - and indeed I haven't had any problems to date.

But I can imagine a situation in very deep single breath dives where the stickiness of mucous might cause trouble in highly collapsed lungs. This is what nobody seems to have any info on.

However it's reassuring to see that people do dive with asthma. In fact it's probably one of the better things one can do to improve it! Matt - it's similar thing with me: as soon as I started swimming and playing squash regularly my lungs got dramtically better. I only wish that more people with asthma could realise this instead of feeling sorry for themselves and actively avoiding excercise...

Bam bam, whenever it's bad, the method I use for mucous clearing is as follows:

1) loosen the mucous by hydration. i.e. have a long shower, drink lots of fluids & take steam inhalation under a towel if necessary.

2) do a series of "huff" coughs. That is, exhale sharply and forecfully at the END of an exhalation, using your diaphragm. This brings the mucous high enough that you can then cough it out in the normal way. This can sound distrssing to passers by so I usually leave it until I'm in the car on my own :)

3) If you can feel that only one lung is blocked then do the above with the base of your tongue twisted to one side or the other. I guess that this must exert some sort of a twist on the passage of the air. I sometimes find that after 10 minutes of work like this, my lung capacity can suddenly increase, accompanied by a loud crack - it must surely be that portions of my lungs start off completely plugged, and then suddenly open.

I hope I haven't grossed anyone out here...

all best,
Hi Pete,
As you said there is not enough information about asthma and freediving. When I was preparing my Internal Medicine graduation work, I propose a work to see the effects of apnea diving in asmathic patient, but my proffesors opinion it that will be worthless and had to change it.
The way we (freedivers) breath that is based mainly in pranayama techniques is very good for asthmathics.
But I have my concerns about deep freediving, as you may know, the only problems with asthma is not the bronchospasm, but the mucus hyperproduction, after a deep dive (50-60 meters) your lungs get really compresed, and I wonder what will happen with mucus plug in the ascent. Of course this is all theoretical.
You said your asthma is moderate persistent, and as you said the symptoms are very rare. Then your Functional Test should be not so good. What is your best FEV1 and PEF? please in % of predicted

My spiro results are as below. I have little experience in interpreting them... can you help me out?!

VC = 5.64
FEV1 = 3.98
FVC = 6.11

therefore, FEV1/FVC = 65%

What sort of results do the best freedivers get?

actually, I guess I should write them out in full:

height: 185cm
age: 28
weight: 82 kg


VC 5.64 86
FEV1 3.98 109
FVC 6.11 96
PEF 591 79
FEV1% 65 54
F50 3.13 34
F25 0.94 46
MEF 2.36
PIF 0.07
MVV 149
FET 6.53
sorry... I can't type for toffee. Try this instead (doh).

height: 185cm
age: 28
weight: 82 kg

BASE %PRED(where applicable)

VC 5.64
FEV1 3.98 86
FVC 6.11 109
PEF 591 96
FEV1% 65 79
F50 3.13 54
F25 0.94 34
MEF 2.36 46
PIF 0.07
MVV 149
FET 6.53

I'm most interested in the bottom part of the table, as that's where all the poor results lie.

Hi Pete,
Sorry for the delay but I forgot it.
The severity of asthma is based on FEV1, an yours (even with my predicted, is normal (87%). So if your symptoms are rare your asthma should be intermitent, and thats is good, the better the lung function is, less will be the complications.
The values in the bottom of the table aren't so important, and can represente the little airways, this values to be significative should be below 50%, so you are not so bad.
I recommend you to get checked by a pulmonologist, in your country.
It's ages since I've been browsing the board! That's full time employment for you... :waterwork

Thanks for the analysis. I'm off to see a dive doctor tonight - let's see what he has to say.

Cheers to everyone who replied.
am I missing something obvious?

My mum and my brother have both had Asthma problems, but I have not - at least, not officially. Mega coughing fits when I am cleaning are not unusual, and I tend to react sensitively to cigarette smoke in the air - I used to have a permanent cough, which I stopped noticing, and I only realised it was due to my wife's smoking several months after she stopped, and it had gone away, until we visited her aunt and uncle (60 a day chain smokers).

Anyway, my point: swimming, specifically diving, is well known as pretty much the best thing to increase lung capacity. Sport, however, in general, is a good thing to do the same, and I don't mean pumping weights in the gym.

It just seems logical to me, that when you increase the lung capacity, a lung condition like Asthma is going to slowly/quickly disappear or be significantly reduced. This would at least tie in with what several of you have said in this thread, and would perhaps suggest that diving (certainly to low depths under watchful eyes) could even be considered a therapy for such conditions ... what do you think?
The breathing pattern that freedivers use is benefical for asthma, it reduces the exacerbations.
The problem is with the depht, even shallow dephts.
In a 10 meters CB dive, the atmospheric pressure change is twice (1 at sea level and 2 at 10 mts), so this also dangerous for asthmatics (moderate to severe) because some air can get trapped in the ascent and cause a barotrauma.
The dive doc had some interesting things to say. I was mainly there to get my PADI form signed off (which he was quite happy do do despite my asthma) but I also had an informal chat about some of the issues that have been mentioned here. Spirometry results like the ones I posted above are apparently fine for diving. He did not seem at all concerned about the possibility of hyperbaric injury due to mucous plugs. He said he has never heard any report of it actually happening. That leaves only bronchospasm as the major risk factor for diving (of any kind).

So the take home message was this: dive sensibly. Don't dive if you need to use Ventolin regularly; take regular steroid inhalers such as Becotide instead. Don't dive if mild or moderate excercise is a trigger for your asthma. Don't dive if you have a cold or a chest infection. My personal (non professional!) conclusion about freediving is that if holding one lungful of air is OK at the surface, then it's probably going to be OK at depth too. It can't expand to a volume or pressure any greater than what it was at the surface unless of course, you surface so rapidly that you shoot out of the water and ascend to 1000 feet :) )

I also agree with what has been said about the usefulness of swimming and excercise in general: maintaining a good level of fitness is far and away the best way to manage asthma. Over many years I have observed that the severity of my symptoms is directly proportional to the amount of time I spend sitting on my backside!

Happy diving to all,
I recently took part in an interesting discussion about asthma and freediving which included an excellent freediver who had severe, asthma as a child, a champion freediver who spent his childhood in a cramped apartment with 2 chainsmoking parents, and a degreed sports physiologist.

The focus quickly turned away from the effects of freediving on asthma and to the opposite causal chain: the effects of asthma on freediving.

The physiologist noted ( and I cannot verify this ) that a recent US olympic swimming team consisted almost entirely of asthmatics. The freediver who had childhood asthma (until mid adolescence) currently does depths and times that are quite surprising in view of her training habits (none) and experience ( infrequent). The champion noted that he had grown up in a thick cloud of smoke, and has lung capacity and other parameters that are just about off the charts.

We ended with a theory that oxygen deprivation, whether caused by asthma or pollutants (in this case cigarette smoke, with the extra added bonus of CO2 and CO) may cause and adaptive response aimed at utilizing available oxygen with greater efficiency: richer capillary beds, etc.

If this is so, then a history of asthma may be associated with anatomical and physiological adaptations which would be an advantage to a freediver.
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now that is interesting. I can quite agree with your theory in principle.

Another contributing factor may be the night-time apnea that many asthmatics (including me) suffer from. Basically, it involves waking up in the middle of the night with a wheezy chest, a light headache and some difficulty breathing. Presumably the headache is caused by mild hypoxia or hypercapnia, so it is not unreasonable to suggest that the body builds up some tolerance to these conditions.
Hi Fellas,
I don't think so optimistic. Sleep apnea is not the same as training, because a life time of hypoxia induces pulmonary hypertension, and righ heart hypertrophia and dilation.
Night wheezing indicates only poor control of asthma.
The fact that many elite swimmers and some freedivers have suffered asthma in childhood, for me, is proof that human beings can overcome any disability and succeed.
The barotrauma during ascent is extremly rare, but it happens (Bayne CG, et al. Can pulmonary barotrauma cause cerebral air embolism in a non-diver? Chest 1982;81:648-650) they describe a case of a breath-hold in a swimming pool, that end in fatal air embolism, the guy was doing 25 yards of apnea in a 2 meters depht pool. The autopsy was conclusive of pulmonary barotrauma and brain embolism.
The theory that air shift within the lung to a compartiment that get full at depht, and get closed off before the ascent can be reviewed at
Dahlback GO, Lundgren CEG. Pulmonary air-trapping induced by water immersion. Aerospace Med 1972;434:768-764

I don't want to sound fatalistic, probably this will never happens to you, but as a physician my duty is to tell you the dangers. You decide on what to do.
Maybe will be good for you to get a peak flow meter, and do a test before dives, in that way you will be fully sure that your lungs are working at full capacity. And of course avoid immersion if you have cold or any lung or sinuses infections.
Hope I don't get bad karma, but facts are facts

Interesting, Frank.

Are the pathologies you mentioned endemic to populations living at high altitudes ? Seems to me your causal model would predict a higher incidence in high-altitude populations than in sea-level populations, controlling for everything else.

It is of immediate, actionable concern, because many elite athletes, including several top freedivers, are now sleeping in
hypoxic tents on a nightly basis.

Paul Kotik