Apple debuted a trio of new heart rate monitoring features set to be included in the Apple Watch series 4. At least one of them was included in watch OS 5 for existing Apple Watch owners.
Apple included support in Apple watch to detect elevated heart rates while in your body appeared to be at rest. Apple also incorporates the ability to detect low heart rates as well.
After installing watch OS 5, if you open the heart rate app, there is a new welcome screen that reads, “Heart Rate can now notify you if watch Apple detects a heart rate that falls below 40 BPM for 10 minutes”.
These alerts will show up on your Apple Watch, and be logged in the Health app. If you launch the health app on your iPhone, you will see a new statistics that tracks anytime a low heart rate is detected.
To adjust this setting, or turn it off, you can head to the Apple Watch app. Under heart, there is now an option for low heart rate. You can elect to disable the feature completely or choose between 40,45 and 50 BMP as the threshold.
Apple watch Series 4 will be able to track low rates.