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

[hotblack]

I understand step count is useless for those only able to walk a few steps a day. But it shouldn't be dismissed for everyone.

Absolutely agree.

It feels like there’s a bit of a mix of things in this thread. Maybe we need to separate people’s experiences (which are subjective and vary but I think need to be acknowledged as valid and often useful) from the question of widespread empirical evidence (which would be objective , work for everyone and is important in the context of claims by workwell and others).

I guess some medics also like things like HR it as it is something they can easily measure, which isn’t the case for so much with ME/CFS

 

[MrMagoo]

But if you're going by whether you feel fine or not, why not simply go by whether you feel fine, rather than going by an HR threshold?

Don’t you turn up here with “logic” and “reason” /s

 

[MrMagoo]

I've been wondering what a good study would look like, because obviously it would be unblinded, so you couldn't trust subjective reports, and the only objective measure would be something like step count - but because pacing is a management tool, not a treatment intervention, success might look like a reduction in steps (to the point where the PwME was PEM-free), or an increase in steps (because careful pacing was allowing more activity by spreading it throughout the day) or no change (because both of those things were in play).

Yes, I'd agree on PEM being triggered by intense activity or lengthy activity is true, although particularly the latter might be PEM being triggered by OI that has been triggered by needing to be upright for a long time to do that lengthy activity.

In a health person, does heart rate not go up over time if they've been steadily doing an easy activity (like steady walking) for a long time? (I wonder if it does in PwME?)

I can only speak to myself but my heart rate jumps up when I go upright, and stays up until I rest.
To get it to do that when lying down I would need to be told something devastating and extremely upsetting.
The more I do, the easier it is for my heart rate to go too fast. So if I went out yesterday, today it’s through the roof making a drink. If I rest yesterday, it’s just a little jump making a drink.

 

[MrMagoo]

I think a meta-analysis of all heart rate studies to see whether Workwell make well-founded claims would be good

I think a meta-analysis of “PEM prevention/mgmt studies” would also be useful.

The question relating to both, thanks to @Sasha for raising it, is there science behind the assertions to manage heart rate, or is it just one of those things that’s become “truth”

 

[Jonathan Edwards]

In a health person, does heart rate not go up over time if they've been steadily doing an easy activity (like steady walking) for a long time? (I wonder if it does in PwME?)

Not in a healthy person, no, and I doubt in someone with ME/CFS unless they were feeling more distressed.

 

[rvallee]

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.)

There isn't much else to work with here than judgment and experience, because to be honest, I don't think the medical profession is able to do something like this. They technically can do this, it's a human problem, but we're dealing with humans as obstacles, so not much to do here.

There probably isn't much to go on with thresholds and this or that explanation. Pretty much all sensible advice is of a rule-of-thumb type, where it's more about keep things stable. Medicine loves to have those thresholds, like the 30 BPM with POTS where 29 is a hard cut-off. Doing hard math on soft data is never a good idea.

I personally have had several explicit experiences where it has been very revealing, where I should have paid more attention to a rising trend. But in its present state, the medical profession lacks the expertise to add anything, this all comes from patient experience and professional "supervision", as they like to call it, is mostly useless other than in confirming what is known professionally to new patients. Although really the only advice they should have should be to send people to patient organizations who would be adequately funded and supported, but that's not happening any time soon.

But the problem is over what is known professionally: almost nothing. Not quite nothing. Just enough to be a problem. Never enough to mitigate that problem. Always just enough to make everything worse without making anything better.

And this is a trend: the medical profession adds nothing at all to the conversation when it comes to chronic illness. Mostly as a choice, or at least as a consequence of poor choices. Everything is up to us, we came up with everything, and until a biomedical breakthrough occurs, it will remain so. I don't think they'll be able to come up with anything at all until we know the pathology either.

 

[jaded]

Are you doubting this response in PwME over time just during an isolated episode of “easy activity” or are you also referring to when in PEM?

In my case it’s both. Heart rate will continue to rise and be high during a simple activity. But if it’s been allowed to continue for too long in terms of prolonged activity my heart rate will be much more erratic the next day.

Just purely waking up and lifting my head off the pillow will trigger an excessive tachycardic response and excessive sweating more so in PEM vs usual. I can subjectively feel this and it shows on monitoring.

In fact even turning over in bed would trigger the tachycardia off. So autonomic dysfunction is a key feature of my PEM but is also underlying each and every day. Not linked to how “distressed” I feel. Although any emotional distress would further contribute to it on occasion but is not a driving feature the majority of the time.

 

[Snow Leopard]

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.

The anaerobic threshold is task specific, it is not a fixed HR threshold regardless of task, despite so many people thinking it is just that. Focusing on the HR at the AT during a cycling test is only really relevant to cycling. Some tasks will reach the AT in specific muscles at very low heart rates and other tasks will never reach a AT, even at elevated ~150 BPM (in middle aged people).

The advice is not to simply avoid short peaks of high heart rates (which will cause deconditioning) but to simply avoid activities that maintain those high heart rates for very long.

If the task is held constant, the HR can be used as a proxy for intensity of effort for that particular task but this cannot be generalised to all tasks.

 

[JemPD]

The advice is not to simply avoid short peaks of high heart rates (which will cause deconditioning) but to simply avoid activities that maintain those high heart rates for very long..

What would be considered ‘short’ peaks? How long are we talking about? 1 minute?
vs ‘very long’ - 5minutes? 10? 30?

And by ‘high’ heart rates you mean above 150 for middle aged person?

 

[Snow Leopard]

What would be considered ‘short’ peaks? How long are we talking about? 1 minute?
vs ‘very long’ - 5minutes? 10? 30?

And by ‘high’ heart rates you mean above 150 for middle aged person?

Less than a minute.

And yes, >150 BPM is a high heart rate to sustain in middle aged or older people

 

[poetinsf]

Some people seem to have success controlling PEM by keeping HR under certain rate, like 95, all the time. The problem with HR, however, is that it soothes out step function. Do squat, for example, HR will rise slightly and then fall back over a period of a minute or so when squat itself last only a few seconds. It may not rise enough even though one squat is enough to trigger PEM in some people.

It may serve as a gauge of intensity for some people if you stick only to lower/steady intensity activities all the time. Never worked for me because my HR is too variable from day to day. Take Sudafed for instance, and my HR used to shoot up to 130 just walking at 90 steps/min on flat ground.

 

[Snow Leopard]

In a health person, does heart rate not go up over time if they've been steadily doing an easy activity (like steady walking) for a long time? (I wonder if it does in PwME?)

This can happen due to central fatigue, basically to maintain the same activity you now have to put in more effort, which is also causes a greater respiratory rate and a higher heart rate in turn. Healthy people need to do more intensive activities (jogging/running at intensity levels past the anaerobic threshold) rather than steady walking to experience this.