Is it possible to query for heart rate without initiating a workout session in HealthKit

I am trying to build an app that will read heart rate samples from the apple watch without initiating a workout session. I was able to make this work, but I am kind of wondering if this is the right way of doing it? I'm suspecting that this might not be the best way to do it as the simulator doesn't seem to display/get heart rate samples everytime. Sometimes it works, sometimes it doesn't. On the actual apple watch, it does work. I'm kind of wondering if I'm missing a step here.

Another related question is that, once I have extracted the heart rate samples, is there a way I can save this in the Health app, since it's not tied up with a workout or should I just save this in core data?

Any help is greatly appreciated.