Why doesn't heart rate get sent to Strava?

We don't collect and store your heart rate data (ie: send it to our server), so it doesn't leave your device nor Apple Health. For that reason we can't send it to Strava - to send data to Strava it would need to go to our server.

We are aware that there is increasing demand for this though, so while we don't currently have an ETA, we are keeping it in mind as we work on further development.