Using Heart rate monitoring to help with pacing.

[Utsikt]

I am not sure about that. Members talk about getting PEM from 'trivial' activities even if moderate I think.

Fair point. I think they use it as «trivial to healthy people», and I use it as «trivial even to other very sick people». I’m bedridden so my frame of reference is skewed.

I have no heard of e.g. mild pwME/CFS that get PEM from walking 10 meters further than they usually do. But that would send someone very severe into a crash.

But that assumes that there is such a thing as 'accumulative PEM' and that it reflects this or that measure of activity. Where is the evidence base for that? We don't have any theoretical base for it so far.

Years of crashing after you don’t reduce other activities when one increases, and not crashing after you adapt the following days. It’s only correlation, though.

Pre-resting is also common, not just post-resting. By the same rationale.

It might, but how are people supposed to use it? How do you calibrate what is the number to aim for? That is what I don't have any insight into.

How do you calibrate your pacing? You do your best and try to learn from past experiences.

We have been very critical of the lack of methodology for other people's evidence. I worry that there is a similar lack of methodology here and that it is only too easy to assume something is helpful when in fact it adds little and may even be misleading.

For my example in the previous comment - my life has been completely standardised in 2025. I do the same amount of physical activity every single day, and mostly at roughly the same times. Deviations in terms of doing more, always have consequences. It’s not a perfect control group, but it’s as controlled as a single person can manage.

I know of many people with the same experiences, but it’s more obvious when you’re severe or worse because your life is so incredibly limited so you don’t have to keep track of too many factors.

 

[jnmaciuch]

That makes sense but my worry is that PEM is not about 'how much I have done'. It is more about your brain's interpretation of what has been going on and your gut feeling may reflect that better than a Fitbit thing.

I appreciate this theorizing but I really don't see any correlation with my experience. My gut feeling has been off quite a lot more than it has been "on", whereas a more objective external tracker tended to be much more accurate. I know that others have endorsed similar experiences. I don't think the same numeric constraints will be applicable between different pwME, obviously, but in my experience it has been a very useful tracking metric for myself

But that assumes that there is such a thing as 'accumulative PEM' and that it reflects this or that measure of activity. Where is the evidence base for that? We don't have any theoretical base for it so far.

Sure, no recognized clinical evidence in a trial, but it is a consistent pattern I have noticed after years of careful tracking. I can literally sum up the math over a series of days and see with pretty good consistency whether it leads to PEM on the nth day. I will readily admit this is anecdotal and I would not want anyone claiming "evidence based" treatments off of that alone. But it is something I really wish someone would have told me to be aware of earlier from a service like the one @ElephantNerd describes

Members talk about getting PEM from 'trivial' activities even if moderate I think.

I have only seen it coming from severe pwME, maybe a one-off mention from a moderate pwME that I missed. Overall, I've seen many more people state that it is a surprisingly consistent threshold correlated with [edit: often cumulative] activity. I really cannot endorse any theory based on the possibility of "trivial" exertion triggering PEM for any severity since that just truly does not seem to be a common phenomenon [edit: across severities]. We talk about exertion triggering PEM because the correlation tends to be quite clear [edit: unless severe]

 

[Jonathan Edwards]

I do the same amount of physical activity every single day, and mostly at roughly the same times. Deviations in terms of doing more, always have consequences.

That is very interesting because it suggests to me that the hypothalamus, under the influence of a rogue immune system, is doing bad accounting but doing it very reliably. I cannot think of any metabolic story that would explain this, although I guess there might be one. My theorising may be entirely wrong but my objective is to put as many requirements on my theorising as are out there and see if it can cope.

 

[jnmaciuch]

I cannot think of any metabolic story that would explain this, although I guess there might be one.

I'm working on it

 

[Utsikt]

But we are talking about numbers aren't we - step count or heart rate?

I don’t think we are, but evidently some do!

The release valve in a strict experience based numbers based pacing system is natural variation due to factors outside your control. You’re bound to either forget your perceived limits or to have to go past them at some point. When you do, and you get a different reaction, you have an indicator for a possible improvement. That and the hunch that people often develop.

The reason I’m cautious about recommending experimenting with your limit is because if you didn’t improve, you just caused more PEM.

I think more people than not are able to pick up on subtle signals when they eventually improve (if they are lucky enough to improve), unless you’ve developed a disabling fear of activity (which a few people do). So I try to encourage people to deal with their fear, because it’s never fun to be afraid, and to learn to rather respect activity.

 

[Jonathan Edwards]

a consistent pattern I have noticed after years of careful tracking.

Again, it seems that something is doing very precise accounting but inappropriately, which is interesting. Presumably the gut feeling of how much you have done doesn't;'t use the same memory stores in this case.

I have only seen it mostly coming from severe pwME, maybe a one-off mention from a moderate pwME that I missed.

It has been mentioned by members I take to be moderately - in terms of conversations, and mental tasks specifically but with an implication that it is more general. There are also members who emphasis the unpredictability of PEM!!

PEM is supposed to be the cardinal feature of ME/CFS so, surely, we really need some objective data on its dynamics. That ought to tell us something important.

 

[Utsikt]

That is very interesting because it suggests to me that the hypothalamus, under the influence of a rogue immune system, is doing bad accounting but doing it very reliably.

It appears to be very reliable for the «over the limit but not full PEM when stable» activities. I can’t speak for the full PEM limit because I have not tested that in a long time.

I also get pretty reliable symptoms from cognitive exertion nowadays. I have experimented with timing and quantity the last couple of weeks, and going back and forth between lots and some produces consistent results. I get full body symptoms eventually, not just head symptoms.

 

[Jonathan Edwards]

I don’t think we are, but evidently some do!

Well you were talking of very precise numbers of metres you could allow yourself to move - that is what I was meaning.

 

[Utsikt]

There are also members who emphasis the unpredictability of PEM!!

I wonder if that is due to instability or not having a clear picture of everything in your account. My experience is that PEM was unpredictable when my life was as well. But that’s just n=1.

PEM is supposed to be the cardinal feature of ME/CFS so, surely, we really need some objective data on its dynamics. That ought to tell us something important.

Absolutely! I mentioned in the new Dara thread that Fluge said they tracked some patients without doing anything to them to get data on how symptoms fluctuate. I have not seen the data anywhere, but I might have missed it. Maybe they would share it with you?

 

[jnmaciuch]

unpredictability of PEM

Sure, PEM seemed incredibly unpredictable to me when I first got ME/CFS, frankly it can still seem "unpredictable" until I turn to my handy dandy external accounting sheet keeping track of cumulative steps and activities, how well I slept, whether I had other symptoms that would indicate I'm on a downswing or upswing, etc.[Edit: is it feasible for other people to keep track of all of this? No. And there might be tons of factors that slip notice which make those calculations seem more unpredictable. But the fact that I can get quite good predictive results using this method cannot be dismissed, in my opinion]

And, again, I must disagree that all cognitive activity must be "trivial"--being in school nearly full time, I can very clearly tell the difference between days when I am reading complex papers, having detailed discussions, and working through coding problems vs. days when I'm just watching the TV for the same amount of hours. It is not equivalent effect in both cases, there is some sort of important difference, it just might not be reflected in measurements of cumulative brain use. But I won't rehash that discussion here

 

[Utsikt]

Well you were talking of very precise numbers of metres you could allow yourself to move - that is what I was meaning.

Ah, I see what you mean now. Those numbers came about after 10 months of experience with a more and more standardised day because I kept removing aspects that was repeatedly associated with flare ups or PEM.

One example is that I had a feeling for a week that I wanted to ask my mum to place the food in my room instead of the fridge. It just sounded like a good idea. And it was once I tested it, so we went with it. Then they went away for a few days months later, and that’s when I got the flare I talked about earlier because I had to go to the fridge again.

 

[Jonathan Edwards]

Fluge said they tracked some patients without doing anything to them to get data on how symptoms fluctuate.

I think F and M did publish on some actimetry with modest but encouraging results but I forget details.

 

[JemPD]

At least the OP may get an idea of how the discussion goes here!

lol indeed

That makes sense but my worry is that PEM is not about 'how much I have done'. It is more about your brain's interpretation of what has been going on and your gut feeling may reflect that better than a Fitbit thing.

For me, yes it's a pretty good judge, EXCEPT when I am stressed. When in fight/flight mode - when really scared or angry my 'gut' can simply no longer be "heard", it just goes offline for a bit, until I calm down & then it screams really loud.

Couple that with the fact that i am an absolute bugger for being ludicrously over optimistic about how much I can do, and ludicrously shocked by how bad the PEM is. I imagine i can do all kinds of things & am always, without fail, shocked by the PEM that clobbers me & then I look back & think 'oh you pillock!'.

The 2 things together are really not helpful.

So while i have always ended up shying away from 'the numbers' approach - for example I never wanted to do 'time contingent' pacing, which is what the clinics often advise i think, or to get caught up in being ruled by numbers, prefering to just judge it 'by eye' so to speak, more recently as the margin for error/threshold has decreased & the stress has gone up, i am seeking to see if i can help myself more with a more objective monitor.

To use the hypothalmus as accountant metaphor, it seems to me that when i'm very stressed something makes it temporarily stop telling me it's measuring, makes it 'run silent', so that I feel like I can do much more, and all symptoms are reduced to allow me to do more (in the moment).... but it's still counting. So that once I calm down it then 'tells' me how much I done (which is always FAAARRRR TOOO MUCH because i had no warning signals, no gut sense that i was going too far) & I start the PEM/crash process. Which is bizarrely then delayed by yet more 'wired but tired' & doesnt fully hit me until after I've slept.

Curiously ibuprofen & strong caffeine also have the same effect on me (of making the "accountant" run silent for a bit.
So stimulants, NSAIDS & whatever chemicals are released when I'm emotionally distressed are 'dangerous' for me because they make the accountant run silent.

OR I guess something could make the accuontant just delay the tallying up for a while, it still being counted but not totted up until later... It goes on its lunch break & only comes back to work when I relax, and has a big pile to catch up on. But the experience is that the price still has to be paid, the 'bill' is still the same, there is just some kind of delay in making the final tally.

I'm hoping if i can make an objective device do the counting it may help. But I only plan on letting it guide me when i'm "adrenalined up" & unable to judge from my 'gut feeling' because i have none.

Its funny though, your 'proposed mechanism' paper, has made pacing a bit easier for me I've noticed over the last few days.... The knowledge that it likely IS actually an immune system thing making me feel the malaise, has made me have less self doubt...

The thing about the 'gut feeling', is that you have to trust yourself to actually listen to it.



I'm so sorry @ElephantNerd this has nothing whatever to do with papers for your later!

 

[bobbler]

I can understand that people do, but I find it hard to understand how you can be sure that these measures add anything to just feeling that you went too far. My guess is that the hypothalamus has a much better idea of whether or not you have done more than the PEM threshold allows because it is probably the hypothalamus that decides that. And the hypothalamus tells us what it reckons all the time.

I think it would be fair for a health care professional to say to new patients that experienced patients find these things helpful. But I don't think they should be recommending them as 'evidence based' and certainly not theory based. And I am interested to know how people know that these things actually do help because it might help me judge what is likely to be a sensible theory to test. At present I am working with the idea that the hypothalamus acts as an 'exertion accountant' in some way dependent on nerves being primed by cytokines and receptors for antibody. The accounting is clearly badly out of line if so. It reads normal levels of activity as danger signals and calls up PEM. There is nothing we can do to prevent that so it needs to be taken seriously, but we don't have a clue how this crazy accounting works or whether it correlates to anything you can measure on a Fitbit.

I'd have to do a lot of thinking back on it, but the thing is that I could well say that the issue is perhaps the opposite, in that it doesn't halt you in time as it would for healthy people/those with other illnesses. And sometimes just pours the energy into the opposite, hence the being unable to get good rest when your body is well-beyond exhausted but also the being able to go well beyond exhausted in the first place.

It does feel like when you are inside it that something is broken in the restoration from exertion 'process'. And instead it engages the 'keep the show seeming like it is still on the road' one, even when inappropriate and it should be hitting the 'whoa nelly, time to sit down and have a hot cocoa' lullaby. So eventually you just end up with unexpected inability to function and collapsing out with rest sort of being like when you hit the defrag function on a computer in the hope it'll clean things up enough the screen will stop being frozen and it won't be quite as slow because nothing else works. So it feels a heck of a relief vs the 'before', but isn't really quite fully completing removing all the grime or fixing the issue of too small memory for the programs you don't want to delete from it.

And continuing to do so even as your body deteriorates over years from that reducing threshold. And then our limits and the immediate and delayed impact of hitting them get looked at with disbelief. And yet sort of the same can still occur. But by that point who knows how much is due to the horror of being trapped in ones own limits for so long and just having a desperate wish to do 'x' overriding other alarm bells, even though it isn't 'sensible'.

But of course this is complicated by culture/a manufactured situational aspect we've all lived in and still do. Where for example even when our body is saying we are done those around us are encouraged not to give our 'no' the time of day at best, or we might desperately need to sit or lie down but aren't at home.

 

[Binkie4]

Years ago I used a facebook group ' Pacing with a heart rate monitor' and found it helpful. It is years since I used it but I did find hrm pacing helped stay within safer limits edit: although it is so long ago that I cannot remember specific examples.

I just had a quick look and it is still there, the old one #1 and a newer one #2. I am not sure how much is openly visible. Maybe I can only see it because I once registered as a member. There is discussion about types of monitor, about aerobic and anaerobic thresholds, about Workwell with people giving examples of how monitor pacing has helped them.

Also Physios for ME produced and circulated there a document with a survey they had done on pacing with a hrm.
https://www.physiosforme.com/post/h...f75epENRXxkK8T8q_Q_aem_LtmQtfAO-fmJ3RA5gF7xzw

"We can’t thank the patient community enough as we received 515 responses within just 3 weeks – a fantastic engagement! We were able to provide some of the raw data to the NICE roundtable discussion as evidence of other management options outside of GET/CBT. "
@Jonathan Edwards

There are also documents from the Bateman Horne centre.

 

[Jonathan Edwards]

Years ago I used a facebook group ' Pacing with a heart rate monitor' and found it helpful. It is years since I used it but I did find hrm pacing helped stay within safer limits edit: although it is so long ago that I cannot remember specific examples.

This is where I am interested to know whether we can get a better idea of what really matters.

Utsikt is saying that PEM risk limits the distance that can be walked/struggled during the day - essentially a 'step count' limit.

Heart rate monitoring presumably focuses on not taking the rate of activity too high.

That raises the question of whether both of these determine risk of PEM, and if so why and in what way do they 'add up' if they do. If both are of importance there ought to be some nomogram that combines values to give you a PEM risk and I have not heard anyone talk about that.

I worry that people think heart rate matters because some of the exercise researchers have claimed that anaerobic thresholds are important. But I don't see any basis for that in terms of evidence, or theoretical explanation of why it should be so.

What I can easily see is that if you monitor and keep below a certain step count and ensure you do not get a high heart rate then very likely you will escape PEM more often. But I don't understand from a theoretical point of view why both of these should limit what you can safely do in a day. Either one or the other might have a limit but I don't understand why both. What seems to me more likely is that both are indirectly related to something else that is what really matters. If so, it might be possible to maintain a higher level of functioning by cunningly avoiding whatever it is that both are indirectly related to. An objective altimetry study ought to provide clues to that sort of thing.

 

[Trish]

For me heart rare monitoring has served more as an objective measure that I need to stop and rest for a while, or avoid some specific activities. I already know that from my symptoms increasing, but it's a more objective reminder to take notice of my symptoms. It's a way I find helpful to give me permission to take notice of symptoms instead of my inclination to ignore them and push on with activity.

For example the arm effort of sorting send folding washing is something I have learned to avoid and get my cleaner to do as it wipes me out quickly. I didn't really believe it could have such an effect until I checked what it was doing to my heart rate.

 

[Jonathan Edwards]

I didn't really believe it could have such an effect until I checked what it was doing to my heart rate.

That is interesting because it suggests that maybe the problem has nothing to do with use of energy in muscles but is to do with what is happening to the heart. Perhaps PEM is all to do with autonomic nervous system signalling in relation to heart activity.

If we knew that then we might be able to conclude that searching for something wrong in muscles was a false quest.

 

[Trish]

Well there is the David Systrom research about preload failure which I haven't tried to follow in depth.

 

[Hutan]

I worry that people think heart rate matters because some of the exercise researchers have claimed that anaerobic thresholds are important. But I don't see any basis for that in terms of evidence, or theoretical explanation of why it should be so.

Yes

Heart rate monitoring presumably focuses on not taking the rate of activity too high.

I haven't used heart rate monitoring throughout the day, other than noticing that, if my heart rate spiked when doing relatively little, that was a very bad sign.

Before I had any sense that resting heart rate might be relevant, I kept a record of it. I'm pretty sure that a high resting heart rate first thing in the morning is a bad sign. It seemed to be correlated with PEM late that day or the next day. To start with, I didn't know enough to see my resting heart rate and make it a self-fulfilling prophecy in terms of the day ahead.

Why would heart rates increase when PEM is coming or present? And not just heart rate, but also shock index. A high shock index definitely correlates with feeling bad for me. I think it might be due to a lower blood volume. I think some fluid moves into tissue - I've mentioned before that PEM, and heading towards PEM, seems to be associated with swelling. If there was an actimetry study, I'd be keen for there to be some way of seeing if what I think might be happening does in fact happen. Maybe a circumference measure on a limb or a finger, maybe a photo of eyes to pick up swollen eyelids?

Lymph nodes often get sore when PEM is starting. I wonder if the lymph system slows down temporarily for some reason, and so blood volume goes down? Being sedentary obviously wouldn't help lymph movement. But, maybe the nerves that make the peristalsis in lymph vessels don't work so well for a while? Would the body think it was a good idea to slow down lymph recycling if it (mistakenly) thought there was an infection in lymph nodes?

I am now way off topic and heading way off down a speculative garden path...