There’s a very interesting discussion about wearable heart rate monitors on Science for ME. I’m not going to reproduce those discussions here but you might want to check them out. It’s free to become a member and it’s a very good forum.
There’s some research which suggests post exertion malaise (the cardinal symptom of ME) occurs, or worsens, in response to exercise and that it may be lessened or avoided by maintaining a lower heart rate. This may explain, at least in part, why people with ME cannot tolerate exercise. Exercise, including graded exercise therapy (GET) is the most dangerous thing a person with ME/CFS can do. So theoretically, by keeping your heart rate down to around 50-60% of maximum you have less symptoms. Or to put it a better way, you can avoid an increase in symptoms. This may still be difficult, or in fact impossible, for some sufferers as their resting heart rate is already close to that 50-60% range and very minor activity, something simple like standing up may push the person over it, but for some it may be possible.
To read the rest of this review, click on the link below: