Can we access HealthKit heart rate directly from the Apple Watch?
I know this is a duplicate question, but no one has asked this in like 5 months. I know you can access it from the Health App but I'm not sure how "real-time" that will be.
There is no direct way to access any sensors on the Apple Watch. You will have to rely on access from HealthKit.
An Apple evangelist said this
It is not possible to create a heart monitor app at this time. The data isn't guaranteed to be sent to iPhone in real-time, so you won't be able to determine what's going on in any timely fashion.