BMJ letter from LongCovid doctors.

[Invisible Woman]

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.

 

[Kitty]

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.

 

[Mij]

@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

 

[Barry]

Personally I've come to the opinion that a greater understanding of exercise physiology in general would be extremely useful to ME research. It seems logical to me that the point where, in a normally healthy person, additional exertion triggers a "fitness improvement" process is the point where PEM is triggered in folks with ME, so if more was known about how that process works normally then it would make it easier to investigate what differences there are in ME.

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.

 

[Mij]

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 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.

 

[Kitty]

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

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

 

[Invisible Woman]

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.

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.

 

[Snow Leopard]

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.

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

 

[Hoopoe]

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).

 

[Trish]

Fascinating. My experience of trying swimming in a small private heated pool was the opposite of what others are describing. I tried it once while my ME was still 'mild' and I was on holiday from my part time teaching job. Just getting myself into the pool and starting to move around in the water triggered a rapid rise in muscle fatigue, and I struggled to get out of the pool and crashed afterwards.

 

[Sly Saint]

he has never ever said publicly that he has changed his thinking at all regarding his beliefs regarding ME

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

volte-face (plural volte-faces)

A reversal of policy, attitude or principle

 

[MSEsperanza]

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

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...)

 

[Hoopoe]

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.

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.

 

[chrisb]

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

 

[Kitty]

Curiously, many participants do not reach a clear anerobic threshold during fin swimming (where the individual gradually increases kicking cadence until they stop).

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.

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).

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.

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.

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.

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.

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

 

[Midnattsol]

I've had several experiences where I've sustained an increased heart rate for longer/walked faster and/or longer than usual/carried more than usual in my backpack etc. without triggering PEM. One of the reasons it's so hard to know what actually triggers and what does not. For me now, I look at heart-rate patterns. If my heartrate has rapidly gone up to say 160, and then had a sharp decline before stabilizing (if it ever does) then I'm more vary than if it goes up to 130 and stays at 130. Presence and level of PEM varies a lot.

I've been struggling to define what my goal with activity is this last year. Sometimes I am more capable of doing bodyweight strength than walking, but other times it's the other way around and I can walk but my muscles are too weak to do any strength training. When I first got ill it started with me not recovering from running, after eventually realizing I was not recovering I changed to weight-lifting and that was working well for a while until it wasn't. In the beginning I would go back to the gym in periods I felt fine, but after three years or so of trying even light extra weight always caused me to crash.

I'm not going to get back the fitness that I lost any time soon, if ever, but when I'm able to work out I do (bodyweight, yoga). I choose hikes over most anything else as that is one thing I miss the most. On days I feel able, I do what I can. On days I don't I do as little as possible.

 

[NelliePledge]

Fascinating. My experience of trying swimming in a small private heated pool was the opposite of what others are describing. I tried it once while my ME was still 'mild' and I was on holiday from my part time teaching job. Just getting myself into the pool and starting to move around in the water triggered a rapid rise in muscle fatigue, and I struggled to get out of the pool and crashed afterwards.

I am ok walking round in the pool and floating. If I start trying to swim I get cramp in my calves very quickly so I can only potter about in shallow water. I can walk for longer/further than I can swim. It was a heated pool but not actually warm.

As I’m having work done on my house and garden all my energy goes on stuff like emptying rooms of stuff so the decorator can paint, shelves built or whatever. Or filling up the brown garden waste bin with overgrown shrubs that gardener has dug up. I can’t assess whether I will be able to do anything like yoga or a short walk or whatever cos I don’t have spare energy for any of that until the refurb is finished.

 

[Hoopoe]

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

Over the first 4–10 days of walking the subjects with CFS were able to reach the prescribed activity goals each day. After this time, walking and total activity counts decreased. Sedentary controls subjects were able to maintain their daily walking and total activity goals throughout the 4 weeks. Unlike our previous interpretation of the data, we feel this new analysis suggests that CFS patients may develop exercise intolerance as demonstrated by reduced total activity after 4–10 days.

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.

 

[Kitty]

I choose hikes over most anything else as that is one thing I miss the most.

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!

 

[Barry]

I choose hikes over most anything else as that is one thing I miss the most.

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