Heart Rate Zone - P description

The app will connect to a Bluetooth based heartbeat monitor (NOT ANT+ / Garmin).
The app has two functions:
- 1. To allow you to work in a heartbeat zone, by setting a high and low threshold.
- 2. To measurer Heart Beat Variations (HRV), this can help you with optimise your restoration times and training frequency.
The data produced can be accessed on the phone in the /Documents/HeartRateZone folder.

Two articles on HRV:
- https://en.wikipedia.org/wiki/Heart_rate_variability
- https://ouraring.com/heart-rate-variability-basics/