Pacing is an activity management strategy to help ME/CFS patients limit the number and severity of relapses while remaining as active as possible.
For ME/CFS patient-pacing purposes the heart rate threshold is set at a percentage of the peak heart rate. The app uses the formula (220 - age) * 0.55. The app also considers the average resting heartbeat of the last 14 days. A heartbeat above 15 beats of the average resting heartbeat is also considered as too much.

This app can give you clues, but it does not replace taking care of yourself and taking it easy if needed.
The app is for the Apple Watch only and will not be displayed on the iPhone. Press the Digital Crown on the Apple Watch to go to the Home screen. There you will find the app.

We use the following rules:
Heart rate is greater than the average resting pulse + 15 in the last 14 days: red circle 100% filled and a soft click.
Heart rate is smaller (220 - age) * 0.36: light, green circle 16% full
Heart rate is smaller (220 - age) * 0.38: medium, green circle 32% full
Heart rate is smaller (220 - age) * 0.40: hard, yellow circle 48% full
Heart rate is smaller (220 - age) * 0.45: very hard, yellow circle filled to 64%, soft clicking
Heart rate is smaller (220 - age) * 0. 55: cautious, yellow circle filled to 80%, soft clicking
Heart rate is larger: red circle filled to 100% and a short warning tone

Pacing integrates with the Apple Health app.