Heart Rate Monitoring
The slide deck from the above presentation can be downloaded as PDF here.
Many people with ME are now using Heart Rate monitors to more accurately pace their daily activity and monitor their body's responses to exertion.
The principle of using a Heart Rate monitor is to stay under the “anaerobic threshold”: the point at which aerobic metabolism switches to anaerobic metabolism (when CO2 is higher than O2 ). The full name is the ventilatory anaerobic threshold (VAT).
For anyone exceeding VAT they can experience symptoms of fatigue, breathlessness, dizziness and nausea. These symptoms will resolve quickly once the exercise stress has reduced.
People with ME respond differently. Using Cardio-Pulmonary-Exercise-Testing (“CPET”) it has been established that people with ME have a reduced VAT meaning they enter their “anaerobic threshold” at much lower levels of exertion. Their symptoms do not resolve quickly and are described as “Post Exertional Malaise”.
The Workwell Foundation have produced this hypothetical timecourse of PEM, which is available to download here.
People with ME can use Heart Rate monitoring to stay below their anaerobic threshold and avoid triggering PEM. The monitor is set to alarm or vibrate when the heart rate exceeds a set level.
Determining the exact ventilatory anaerobic threshold is done using Cardio-Pulmonary Exercise Testing, however it is possible to calculate estimates.
Workwell Foundation suggest the following:
(220 - your age) x 0.55 = anaerobic threshold in beats per minute
If you are 30 your VAT (220 – 30) x 0.5 = 105 bpm
If you are 45 your VAT (220 – 45) x 0.5 = 96 bpm
Some people prefer to work out their resting heart rate (taken at complete rest) and then aim to stay within 10-20% of this rate.
Remember that any treatment for someone with ME should be individual, constantly monitored and evaluated, and we would recommend exploring all the resources below further before considering using this method, with support from an experienced health professional.
You can find overall guidance, recommended devices and further resources at this webpage here
You can read more examples of using Heart Rate monitors for people with ME on the following pages:
Physios can read this Workwell Foundation case study on using HR monitoring to structure exercise
CPET information can be found here
Heart Rate Variability information
Postural Tachycardia Syndrome (POTS) information
These groups offer opportunity to talk to other people with ME who are actively using Heart Rate monitors: