What empirical evidence is there that heart-rate monitoring helps avoid PEM?

[Sasha]

I see a lot of discussion both on S4ME and all over the Internet about how PwME are using heart-rate monitors as a pacing tool. They're trying to avoid going over their aerobic threshold, on the assumption - apparently coming out of Workwell - that crossing your threshold is what leads to PEM, and of course pacing is all about avoiding PEM.

Is there any scientific evidence that PEM is caused by going over your AT threshold? Or that heart rate monitors are any use in pacing? (Please, no anecdotes of your own experiences! The thread for that is here.)

The quotes below are from a year ago.

Is there no decent evidence behind the Workwell Foundation basic anaerobic threshold theory (which Visible is based on) increased heart rate would be easy to demonstrate, we just need the studies which link it to PEM/relapse.

I am pretty sure there is no evidence at all. I see nothing that indicates that anaerobic threshold is relevant. When someone wakes the next day, and the days after for weeks, feeling much worse there is no plausible reason why that should have anything to do with aerobic threshold being crossed some days before. And if PEM can be produced by bright light or travelling in an ambulance the whole aerobic threshold idea makes no sense. I am afraid that it is probably pseudoscience as much as the BPS theories. This is why I see the patient so much as wedged between two piles of nonsense.

 

[Yann04]

They're trying to avoid going over their aerobic threshold, on the assumption - apparently coming out of Workwell - that crossing your threshold is what leads to PEM,

I think most of the people doing it don’t necessarily think that. Just that heart rate is a useful proxy for exertion level for them. I’d look at it more like a “warning sign symptom”.

Ie. hearts racing, getting a headache, mini tremors etc.

 

[MrMagoo]

If I recall correctly, Visible data was used by someone and they're claiming they can “predict” crashes. Maybe Visible themselves, or Putrino?
Whatever it was, over a year ago, I wasn’t convinced and I like my Visible a lot.

Personally I agree with the above- it broadly shows you want is rest/effort/serious effort and you can adjust what you do so it’s less of a strain. Or see how much strain you’ve done, and take a rest sooner rather than later.

The three “levels” of rest/aerobic/anaerobic use up the budgeted points at different rates. The fastest way to use points is anaerobic, but it’s not discouraged that you avoid getting to that state, not at all. It’s also fairly impossible, it doesn’t take much to get into anaerobic. Standing up usually does it.

I am not convinced that people who live by it and endlessly analyse data and gnash and wail about “going over budget” are using it well, nor am I convinced that you can do very specific things like avoid PEM, but this is drifting into opinion. It is a tool you can use, the tail is wagging the dog in some instances.

 

[Kitty]

Is there any scientific evidence that PEM is caused by going over your AT threshold?

I very much doubt many of us go anywhere near the AT while we're getting something to eat or visiting the loo. Many of us won't have seen it for decades.

Severely affected people would never experience PEM if triggering it required that level of sustained activity.

 

[Trish]

Heart rate monitoring has been recommended as a guide to when to stop exercising and take a rest for ME/CFS for decades. Even the 2007 NICE guidelines and the PACE trial used it specifically for GET as a way of indicating exertion level during their daily exercise session (usually walking). They were told to keep their heart rate below a specific level. There may be references for the source they used in the refs on the PACE paper.

Elite endurance athletes such as road cyclists wear heart monitors which are continuously monitored to ensure they don't go over their limit. There may be something from sports science that's relevant.

I think for ME/CFS it's not so much a scientifically proven PEM prevention as a part of the clues a pwME can use to help them recognise when they have been exerting more or for longer than usual and may be risking triggering PEM. Along with symptoms such as fatigablity and OI it is an indicator of time to take a break.

 

[bobbler]

I see a lot of discussion both on S4ME and all over the Internet about how PwME are using heart-rate monitors as a pacing tool. They're trying to avoid going over their aerobic threshold, on the assumption - apparently coming out of Workwell - that crossing your threshold is what leads to PEM, and of course pacing is all about avoiding PEM.

Is there any scientific evidence that PEM is caused by going over your AT threshold? Or that heart rate monitors are any use in pacing? (Please, no anecdotes of your own experiences! The thread for that is here.)

The quotes below are from a year ago.

Agree with points other have said

Just in case it’s been misinterpreted on other posts from me, but I use the term ‘threshold’ on its own a lot to mean something that is certainly not anaerobic threshold but a loose term for ‘the AMOUNT that causes either PEM or often the wired tired or fatiguabikity’ ie it’s just a normal word meaning something important that we have a term for but isn’t linked to this theory of anaerobic etc.

So I think it’s worth making sure the full term is being used if one means or us talking about anaerobic threshold and assuming that isn’t what’s meant (but just the word threshold, which also can be cumulative) unless both words are used.

The examples given aren’t from a thread that’s to do with pacing or HR monitoring but something else, so it would be useful to have pointers to examples of some of the lots of you are referring to that do join these two things together to see what you are thinking of when referring to it etc?

As others have said these can /are two separate things I’ve mainly seen talked about separately. And I can’t tell whether you are asking whether any scientist has seen whether the few who can somehow reduce how much they hit the AT (and how that might be measured?) did actually have less PEM and how that was /can be measured?

 

[Sasha]

I think for ME/CFS it's not so much a scientifically proven PEM prevention as a part of the clues a pwME can use to help them recognise when they have been exerting more or for longer than usual

PwME surely go over their AT all the time as part of normal life, because Workwell suggest that for PwME, the AT threshold can be best estimated at resting heartrate plus 15 bpm, which barely allows scope to climb a few steps, or walk a few dozen yards. If there's no good theory or evidence behind it, why stick to the AT threshold and not something lower or higher?

I'm really struggling to understand the relevance of HR at all.

 

[Kitty]

Elite endurance athletes such as road cyclists wear heart monitors which are continuously monitored to ensure they don't go over their limit.

A lot of heart monitoring is keeping people in their training zones. It's carefully staged building up to competitions, and it's done to ensure they're training at the level they need to be at that particular time—they might be overdoing it, but they could also be under-doing it. During competitions data is collected to inform future training.

Ultimately it's geared to pushing their performance limits as far as they can sustain. I'm not sure how useful the techniques would be to people whose need for measurements nearly always arises because they need to do less than they currently are.

 

[Yann04]

I'm really struggling to understand the relevance of HR at all.

some people get tachycardia when theyrr doing too much. sometimes you dont notice it. setting an alert or tracking throughout the day can help you see if you might be overdoing it

 

[bobbler]

I very much doubt many of us go anywhere near the AT while we're getting something to eat or visiting the loo. Many of us won't have seen it for decades.

Severely affected people would never experience PEM if triggering it required that level of sustained activity.

I’m confused how we are defining the term of anaerobic threshold of hitting it

It’s not or is it the same as heart rate increase for a start albeit I imagine there is a correlation somewhat ?

 

[MrMagoo]

I very much doubt many of us go anywhere near the AT while we're getting something to eat or visiting the loo. Many of us won't have seen it for decades.

Severely affected people would never experience PEM if triggering it required that level of sustained activity.

I can go over it by drying a dish. It’s all relative. I’d imagine if I was severe/very severe I’d go over it if someone started banging around or told me sad news.

 

[Kitty]

Workwell suggest that for PwME, the AT threshold can be best estimated at resting heartrate plus 15 bpm, which barely allows scope to climb a few steps, or walk a few dozen yards.

I'd value @Snow Leopard's view on that. It sounds like proper codswallop to me—either that or that they're muddling up PEM threshold with anaerobic threshold.

I don't think the precise moment that's called the AT is obvious to the person working out, but the state of anaerobic energy production does become obvious after a bit. I swim laps of freestyle when I'm well enough, and I don't experience that sensation of lactic acid build-up even when I'm training at 85% of my notional maximal heart rate. I haven't felt it since I last went hillwalking in the 1990s.

 

[Sasha]

some people get tachycardia when theyrr doing too much. sometimes you dont notice it. setting an alert or tracking throughout the day can help you see if you might be overdoing it

That's not to do with pacing or avoiding PEM, though.

 

[hotblack]

Yeah, at least for me HR has been a significant part of my illness. Now what that means is questionable. HR seemed to be a useful indicator but it was more a case of you’ve already done too much, stop. HRV was maybe more of an early warning sign, but tbh I’m not sure how accurate it was. It did help me learn a bit I think, but as an ongoing tool, not useful enough to buy a new monitor when the one I had broke.

 

[MrMagoo]

I'd value @Snow Leopard's view on that. It sounds like proper codswallop to me—either that or that they're muddling up PEM threshold with anaerobic threshold.

I don't think the precise moment that's called the AT is obvious to the person working out, but the state of anaerobic energy production does become obvious after a bit. I swim laps of freestyle when I'm well enough, and I don't experience that sensation of lactic acid build-up even when I'm training at 85% of my notional maximal heart rate. I haven't felt it since I last went hillwalking in the 1990s.

Wow I get lactic acid buildup from having a shower

 

[Sasha]

So would I be right in saying that there's actually no study-based science showing that heart-rate monitoring helps avoid PEM?

 

[MrMagoo]

This is the references from Workwell’s guidance

 

[Yann04]

That's not to do with pacing or avoiding PEM, though.

Yes it is. If you’re tracking a warning sign symptom to avoid doing too much. That’s a part of pacing and is used to avoid PEM.

 

[bobbler]

PwME surely go over their AT all the time as part of normal life, because Workwell suggest that for PwME, the AT threshold can be best estimated at resting heartrate plus 15 bpm, which barely allows scope to climb a few steps, or walk a few dozen yards. If there's no good theory or evidence behind it, why stick to the AT threshold and not something lower or higher?

I'm really struggling to understand the relevance of HR at all.

But that’s different when they are stating that in the context of eg if someone is doing a CPET exercise test and are saying effectively that the work done means the fuel source has now switched like someone in a marathon switching to a sprint at the end might be ok for 200m until empty but they wouldn’t want to be doing that in the middle of their 26miles etc unless it was a much short bit eg to overtake or something I guess

is this line specifically from work well taking on the 2-day cpet or from a hr thing? I’m assuming if the latter there is more to the sentence that might help

as I think the context and specifics are really key here to get what you are referring to

 

[Sasha]

This is the references from Workwell’s guidance

That's quite the claim they're making! Do they have a reference that actually backs it up with data?