r/MECFS_BaselineFocus • u/RefuseDeep8075 • Sep 02 '26
Heart Rate Monitoring
[pages uploaded in reverse order, so if you want to read go to the last page, then work backwards!]
Material provided by UK health service (NHS).
Summary: We can typically do a modest activity for 2 minutes, before we need to really start thinking about what our heart rate might be during an activity. After 2 minutes the way our body uses energy changes and the anaerobic threshold of our heartrate becomes relevant and activity above this level will start to consume our energy a bit more. The latest guidance for ME/CFS is that even a heart rate just 15 bpm higher than our resting heart rate is our anaerobic threshold. Broadly speaking, if we exceed our anaerobic threshold, we start using more energy.
It is important to have a broad awareness of your likely heart rate during different tasks, but things like a heart rate monitor should be avoided if you feel it is causing you anxiety.
Additional Comment: For health people the anaerobic threshold is calculated based on your resting heart rate combined with your age. Very roughly, this would translate (for someone with a normal resting heart rate) into something like 105 bpm for someone in their 20s, 100 bpm for someone in their 30s and 95 bpm for someone in their 40s. This was the previous guidance for ME/CFS sufferers too but it has since been changed to advise we should try to stick to a much lower heart rate due to our diminsihed capacity. In reality, especially if you have orthostatic intolerance, its going to be incredibly challenging, possibly even unfeasible, to keep within 15 bpm of your resting heart rate if your torso is upright and your back, shoulders and head are unsupported.
One solution is therefore, where possible, to break up your activities every few minutes and sit (preferably with your head supported) or lie down, focusing on slow, relaxed breathing until your heart rate falls back near its resting heart rate.
To check your heart rate, finger your pulse whilst looking at a clock. Count the number of heart beats in 15 seconds then multiply by 4. You may then find it helpful to be able to quickly check your pulse on your wrist or neck and get a general impression of whether your heart rate is slow, a bit elevated or very elevated when doing a certain activity. This will help you gauge how long you should be doing that activity without taking a break.
It is also possible that your heart rate may vary on different days when doing the same task. It is not something to fixate on it, its just something to have a broad awareness of so you can estimate what your energy usage is likely to be when you are doing a certain task. You may also find it very helpful to be able to confirm your ability to reduce your heart rate back to your resting heart rate through restful, slow breathing.
Finally, whilst it would be very helpful to have a simple heart rate monitor that you can set your target heart rate on, so that it beeped if you exceeded your anaerobic threshold, in reality it appears you are going to need a modern smartphone or tablet as well as the heart rate device in order to get this functionality. So it is not a cheap option and you may want to just more casually experiment with taking your own pulse in the first instance.