Heart Rate Monitor
One of the first health features found on the original Apple Watch was a heart rate sensor. Upon request, your Apple Watch can give you a beats-per-minute heart reading in just a few seconds. However, it also tracks your heart rate when you’re sleeping or just relaxing, giving you better insight into how well your heart is working.
What’s even better is that your Apple Watch can also notify you whenever it detects your heart rate is unusually high or low for the activity that you’re doing. This feature alone has helped a lot of people, so it’s something you’ll want to try.