Asthma and marathon swimming – Part 2

Part 1.

Continuing on from the previous article on the subject, I’ve made a point now of completely abandoning the pool during the summer, allowing my lungs a break from chlorine. I have to try to remember this as it would be easy for me to go back to the pool especially if I want to do some speed work before a race. (I can’t seem to do much speed work in open water by myself). During the summer, without discussing it with my GP, I also stop using the Serevent Asthma Preventer, as I continue to be concerned with long-term use of a by now more powerful beta-agonist.

This is a personal decision, I’m certainly not advocating it.

Before I continue on this a brief digression into asthma and chlorine is warranted: Chlorine in pools is not in itself the problem. Chlorine interacts with organic compounds (such as urine, sweat, shampoo, soap, perfume, deodorants) to form tri-halo-methane gas. This is an odourless, colourless heavy gas, which can inhibit  or damage respiratory function and sits on the surface of the water and may be the cause of increased asthma amongst swimmers, and those who swim the most, children and elite swimmers, are those most affected. It why you should ALWAYS shower before swimming, and so should everyone else, and why pools make note of this important point.

I also, like most asthmatics, make a point of having access to a Ventolin or Salamol Reliever pretty quickly. This means there is always an Inhaler in my car, one in my swimming box, one in my pool swimming kit-bag, and two in the Loneswimmer Castle, one downstairs, and upstairs in the South Tower. Contrary to what you see on TV, using an asthma inhaler doesn’t lead to instant relief.  And I also rarely have to rely on any of these.

Next in my process is having a Peak Flow metre. When I remember to do so, I use one like the one on the left here.

You’ll notice that one has coloured bands. A peak flow meter measures the person’s ability to inhale (through measuring quick exhalation). A reading from 50 to 250 litres per min, under the red line, is dangerous. 300 to 600 is amber, and above 600 is normal.

All one does is exhale quickly and hard three times, and look at the maximum of the three for the reading. Since everybody’s aerobic capacity drops at night, one does this in the morning. If one use a peak flow meter daily, as is recommended, one charts one’s daily morning reading on a simple one page chart. You agree with your General Practitioner the reading which is the trigger for concern and a possible Doctor’s visit. I don’t want anything to mistakenly think this is something you can pick up from me, so I won’t tell you what my trigger is, except that if it occurs three days in row, I should visit my GP.

Here’s the interesting thing for most of you:

As a distance swimmer, who trains regularly and hard, my usual reading is 600 litres per minute or just under.

I am on the border between below average and the very low-end of normal. I just took it now, for this article, a couple of weeks after returning to pool training, and I measured 550 l/min. At my best, I will dip into the very low-end of normal. I put that to you as a positive if you are an asthma sufferer. If I can do it…so can you.

Now, I’ll also be honest and tell you I often get completely out of the habit of using my Peak Flow metre and forget about it for months on end. But being back in the pool, with winter coming on hard, I try to start using it again.

Wait, I’m not finished. I also use heart rate monitoring to monitor my fitness, if I’m getting enough sleep and as an additional asthma check.

Again recently, but before I returned to VO2 max and anaerobic and more strenuous training, in fact after a few weeks of low mileage and taking it easy in the sea, I had a medical which included an ECG. I had had coffee that morning, which raises heart rate.

My heart rate was 54 bpm. Not bad considering I wasn’t in great shape. In fact the nurse said I was bracycardic, i.e. that I had a lower than normal for my age heart rate, until I explained I was a swimmer, and that was normal for me, and would go lower with training.

Now, years of exercise have told me I’m not naturally bracycardic, like Dee, and in fact my heart rate before that lifetime of exercise was probably slightly higher than normal. (I always find it funny how men and teenagers particularly like to compare heat rates and boast).

I have a laminate page beside my bed, which I don’t notice over 95% of the time, but when I do, I check my heart rate before I get up in the morning, again the best time to check. An HR of 60 or above will tell me I’m tired, overtrained, not getting enough sleep or have some cold or illness coming on. I’m not regimented at this, but it is a really useful tool and I know 60 is my upper level.

I also use this free Android heart rate app on my phone. And in a effort to validate its accuracy, I used it immediately after my recent ECG, and the difference was 1bpm lower, within the margin of error. But a simple pulse check with your fingers will work once you get used to doing it.

I have to be very careful about illness. I now get the influenza vaccine every year, I only started in 2008 when I was training for the English Channel relay, and I have to say it’s been a great aid.

The normal problem I encounter though is get a cold, which will ALWAYS lead to a chest infection for me, which will then precipitate an asthma attack. So as soon as I detect any hint of infection (morning cough, sniffles) I visit my GP within 24 hours, and get an antibiotic to reduce the impact.

Here I have to say though, swimming in cold water year round, I am less prone to these colds for the past six years. While I can’t quantify that, it is the same immune system improvement many open water swimmers report.

Extreme emotional stress which comes on suddenly, at least for me, is also an asthma trigger, but of course there’s little any of us can do about this.

Testing with Clare off Orca and Helvick Head

For two hour pool swims I use an inhaler before and for my longest swims, 4 hour plus pool training swims, 5 hour plus sea swims, I use an inhaler beforehand and during the swim. During the English Channel I had scheduled in two inhaler stops with my feeds, and Clare and I had tested using the Inhaler on an offshore swim off Helvick Head in choppy-ish conditions (test everything remember).

For very long pool swims in chlorinated pools, everything becomes more critical. For the 24 miles in 24 hours swim, I chose Kilkenny Pool because of its ozone-based water treatment approach, not just for myself, but for all the swimmers.


  • Monitor and chart lung capacity daily with a peak flow meter. Know your own reading. Don’t worry about anyone else.
  • Use a daily Asthma Preventer. Agree the best option with your own GP (MD). Discuss your trigger and action points.
  • Monitor your heart rate.
  • Use an Asthma Reliever (salamol etc) before long pool swims. Learn to use it for marathon swims. If you do suffer asthma, make sure your crew understand your requirements.
  • Keep a close eye on any respiratory illnesses. Understand your own health cycle and take ownership of it.
  • Be proactive instead of reactive, as with everything else in marathon swimming…be prepared, this is yet another aspect of open water safety.

10 thoughts on “Asthma and marathon swimming – Part 2

  1. This is probably a silly question ive inky recrntly gotten into open water swimming. I have asthma which is fairly well controled but i still get an attack every few weeks when i swim in the pool i leeave my inhalor at the top of the lane and everyone know about my asthma etc but im having trouble with the open water, i leave it on the shore with family but what happens if i need it in the water its not as instant access as at the pool. Any hints or tios would be greatly appreciated.


    • Hi Grainne,leaving aside all other questions or possibilities, I’d say they are two simple solutions:

      1. Tuck it into your swimsuit. It’s waterproof and one blast will clear whatever little might get into the nozzle.
      2. If you are afraid of losing it, then I’d recommend a safety buoy like the Chill Swim Tow Floats, the medium sized one has a small dry bag.


  2. Let us know, if you would, how your asthma progresses from time to time. Like most asthmatics with adult onset, I went through a similar cycle of albuterol when needed, not wanting the steroids, then not having a choice, then figuring out which best for me. In the end, for me it was Symbicort, very similar to your dual acting inhaler and over time (~2 years) I’m able to get down from the highest clinical dose 2x day to the lowest clinical dose once a day and my numbers are improving. My pulmonologist said it can be put into remission, it just takes time. For me as well, a puff or two of albuterol prior to a workout makes a big difference in how I feel in the pool. Thanks for sharing ALL of your great thoughts. Much appreciated.


    • I shall do, Will. I haven’t had an attack in a year, only using the Seretide in the winter, at half strength. Getting the annual ‘flu inoculation seems to be a key thing for me also, avoiding the worst of the winter chest infections.


  3. Awesome article. I am an extremely active male over 50. My main exercise is advanced mountain biking. To train for a triathlon, I recently began pool swimming (1 mile, working hard). I have been feeling this sensation of shortness of breath, and wondering if I am about to have a heart attack (the mind really plays tricks when you don’t know what the hell is going on). I have a resting heart rate of 42 bpm and am certainly not used to not being able to sleep because I can’t take a deep breathe. Having read your post, I am pretty sure I understand what has triggered my unease and I now plan to go back to bed and probably sleep like a baby because I will be way more relaxed. Thanks.


  4. Great article regarding asthma and swimming. I would just like to make you aware of the Asthma Society of Ireland. There is lots of information on asthma, medications and treatment and exercise with Asthma. There is a helpline where you can speak with an asthma specialist nurse to discuss any queries with your asthma. they are a great help.


  5. Thanks very much Janet.

    I added a little D-clip through the plastic so it can be dropped down on a string from above, but I have to say I don’t worry about water aspiration. I figure for a long swim I’ll aspirate some small amount anyway, from spray if nothing else, especially if there is any chop in the water. And I think the amount of water molecules aspirated by being carried on the aerosol would be low. Sorry I can’t help more.


  6. Thanks for all the great info on training and swimming with asthma. I also use inhalers both before and during longer swims (every 4 hours), and was wondering if you had any suggestions for how to keep the inhaler dry on its trip from the boat or kayak to you. (I worry aspirating water droplets when I medicate if water gets inside the inhaler). I’ve put mine in a zip-lock bag, but that’s a little time-consuming for me or the kayaker to open. Any thoughts?


  7. Pingback: Asthma and marathon swimming – Part 1 | LoneSwimmer

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