BMJ letter from LongCovid doctors.

Earlier on & when less severely affected by ME, I could slowly rebuild and maintain muscle tone if I very carefully avoided aerobic exercise. Until I became severe enough so it was no longer possible. I find myself wondering if attempting to maintain muscle tone (& rebuild after setbacks due to all sorts of reasons) is one of the reasons I became so severe. I don't know for sure but folk I know who didn't bother don't seem to have worsened in the way I have.


In PEM I can experience temporary power failure so I fall because one or other leg decides it can no longer hold me up (though the leg isn't completely paralysed). The same thing can happen with my arms. No warning.

The power does come back but I will be very weak for hours if not the rest if the day and beyond.

 

PEM just baffles me.

There are frequent minor exceptions, where for no obvious reason PEM doesn't match up to effort expended. I've come to expect that, but a handful of times a year there are aberrations that seem to defy all logic.

I had one four weeks ago. Usually, when I'm able to swim, I only enter the aerobic heart rate zone for half the session at most. Sometimes it's much less than that, and I've done plenty of swims where I never entered the zone at all. Occasionally I'll hit peak rate for three or four minutes, but I really try to avoid this because I'm worried it will trigger severe PEM.

On this particular day, I swam slightly more than my usual distance, and a good bit faster. I recorded 45% of the session at aerobic, plus 40% at peak. I'd felt great during the swim, but I was bloody scared when I saw the stats. I immediately cancelled two appointments in the following few days, expecting to be in a bad way.

But nothing happened. I felt tired afterwards, as usual; I didn't sleep very well, as usual; I needed a couple of rest days, as usual. But then I was back doing another swim on day four, recording my usual heart rate measurements.

Normally, I'm not capable of achieving those stats even if I tried. I don't understand where freak capability like this comes from, what causes it to happen, and why there are no consequences.

I've just looked up the other handful of occurrences, and the earliest one where I had a heart rate strap that works reliably in water was three years ago. So even if I do have to take a complete break from swimming again due to a worsening – which, let's be realistic, is inevitable – these exceptions aren't causing relapses that are closely connected in time.

 

@Kitty

This has also happened to me. I don't monitor my heart rate, but last fall and several months ago I was able to power walk for 3 evenings IN A ROW. I reduced the time for the next 2 evening walks because I was afraid to trigger PEM. I felt normal after, no fatigue the next day or even any indication that I had been out walking. It really baffled me why I felt so good for the remainder of the week, but I didn't dare do anything too strenuous.

I'm still suffering from vestibular neuritis so haven't been out in a few months, but I can't wait for it to be over so I can go out again to see if I've actually improved

 

I have no medical expertise at all as you know, but my lay person's impression is that the normal fitness improvement process, induced by pushing through normal physical limits, is the very process that is broken in pwME, and harms instead of helps.

 

I was trying to maintain what I already had, but I don't think I was ever able to rebuild any muscle loss since having ME. The noticeable muscle loss only starting becoming visible in the last 5 years.

 

Oh, no – I sympathise, I'm prone to labyrinthitis. Horrible! I hope you're better soon.

 

I actually did regain a little of what I had lost but muscle tone rather than mass. Only by taking it very, very slowly and carefully. In hindsight I'm not sure I did myself any favours. I no longer have the capacity to even consider trying it.

 

You are not the first to describe curious experiences with swimming.


Curiously, many participants do not reach a clear anerobic threshold during fin swimming (where the individual gradually increases kicking cadence until they stop).
https://pubmed.ncbi.nlm.nih.gov/20535660/

Also notably, participants reached their VO2Peak at much lower heart rates than cycling and running.

One key point I'd like to point out that the "anerobic threshold" is not triggered upon reaching specific heart rate, except when doing exercise with a ramped increase in force output (like a CPET protocol).

I discussed the significance here:

https://www.s4me.info/threads/under...d-jammes-ritornaz-nov-2019.12579/#post-222450

 

My experience with swimming is that the PEM threshold appears to be higher compared to say walking, despite swimming feeling like it involves substantially higher intensity of exertion.

Swimming with frequent pauses in a cool freshwater lake also appear to have different effects on the body than walking. Something about the swimming is calming. I think it might be effect of the cool water.

I have noticed that coming out of the water I'm tachycardic but that might be due to the cardiovascular system having to adjust to being upright and no longer in water (which would help with orthostatic intolerance).

 

in his own words on that tweet;
"no volte-face"

https://twitter.com/user/status/1306531570396753921

 

Very much my experience. Whereas staying more than a few minutes in warm (not even hot) water makes my muscles weak and me dizzy, also in the bath tube without moving much.

The challenge is only the way to the lake/ cool pool and back, so that it has become a very rare pleasure to go for a swim.

(Maybe simply a kind of heat intolerance. I also prefer to eat my meals cold or luke-warm. Big fan of Gazpacho-like soups...)

 

I didn't feel like I would be able to go swimming without a car because the traveling would otherwise consume much of the energy budget needed to actually swim. I found someone with a car who lives in the same house who likes to go swim often which made it possible.

 

I've heard of swimming with dolphins, but swimming with cars is a new one.

 

Interesting! Thank you, I hadn't heard that. I haven't had swim coaching or read about technique and training methods since I got ME in the mid-1970s, so that's new to me.

Yes, I do understand that. I use the term 'training zones' loosely, but I am comparing like with like – my own heart rate, whilst doing the same activity. There seem to be multiple reports that the higher the sustained heart rate, the greater the risk of a bad PEM episode, so I regard what my HR monitor describes as the 'peak zone' as best avoided until I see evidence to the contrary. I'm not trying to get fitter or improve my athletic performance anyway, just to stay mobile (I have psoriatic arthritis) and keep my heart and lungs working, as I'm unable to do so by walking or other land-based exercise.

It's interesting, isn't it. That's my sense of the experience, too, but I don't know how to compare it with other activities in a meaningful way. The horizontal position you adopt when swimming freestyle and backstroke, and the pressure of the water on the vascular system, probably come into it somehow.

It's not always the same, though. I can swim the same distance at the same pace half a dozen times, but both my heart rate and the level of PEM I experience afterwards will vary hugely between sessions, almost certainly due to the amount of 'rolling PEM' I had when I started. And I don't think sustained heart rate and PEM are linked directly, closely, and consistently, though there appears to be some kind of relationship – except on the rare occasions where there really isn't, in that peculiar and apparently inexplicable way.

Me too. Had to give up warm baths years and years ago, because my muscles went so floppy I couldn't climb out.

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1280928/

It doesn't mention PEM but this could explain part of the unpredictability of PEM. If you keep to what appears like a safe level of activity, what might be happening is that exercise intolerance develops and the PEM threshold decreases. This exercise intolerance could build up slowly over days or weeks. I think something like this would explain a lot, since I tend to have periods of weeks to a month or two were I'm apparently capable of doing more and they often end with bad PEM episode.

 

Me too! It's something I started even as a baby, with my Dad pushing my pram around the Derbyshire peaks with a radio shoved down the side playing Test Match Special. Later, I started getting out of the pushchair to walk a bit until I got too tired, then later still we began going on hikes of increasing distances nearly every weekend. I carried on as an adult, and even after I got ME there were several periods when I could do 15 miles over the hills of western Sheffield, the Derbyshire peaks, or the North York moors, two or three times a month.

I need a powered wheelchair now, but I found myself replacing the hiking with wildlife watching. The views are a bit different, but the desire to be out in the elements is just the same!

 

So true of my wife also, in conjunction with missing seeing the places you can only get to by walking there.