Hi Malcolm,
Welcome to the Frontier heart Forum!
The Frontier X is a great tool for exercising when you have cardiac concerns.
Here are 3 tips to get the most out of your Frontier X.
1. Set vibration alerts.- set alerts on heart rate, breathing rate or cardiac strain to achieve your training goal. Link

2. Review your training load to compare your training load from different types of workouts like cycling and running. You can use the Target Training load circle to guide the total amount of training you get in a week. We recommend getting it to the green or yellow zone! In case it turns red, we suggest you prioritise recovery in the coming days because it may be an indicator that you are training too hard too quickly.

3. In case you are feeling symptomatic during exercise you can use the event marker (press the red button on the Frontier X once ), this will allow you to review that section of the ECG after your workout. We suggest waiting for 30s at rest after your symptoms begin and then press the button so that you get the best ECG signal to review.