Tracking a workout with ST watch app:
* make sure Sync from Apple Watch setting is enabled in ST iPhone app before starting a new workout
* open the ST watch app
* choose desired activity type
* press Go!
* track the workout
* swipe to the left to finish tracking with the Finish and save button
* open the ST iPhone app to view the finished workout

The workout will synchronise automatically to your account. Make sure the watch is connected to the phone. (Swipe up the watch screen on watch face to find green phone on top left. If red make sure your phone is near enough and bluetooth is enabled)
You'll receive a push notification when the activity is synced. (if push notifications are enabled in app settings)

The app uses the integrated wrist heart rate monitor by default.
If you wish to use a Chest Strap Heart Rate Monitor instead with the watch app you need to pair the HR monitor in the Apple watch in Settings in Bluetooth - Health Devices. The app prioritise the HR monitor always if it can find it.
Before workout make sure the Apple Watch has found and is connected to the Heart Rate Monitor in Settings - Bluetooth - Health devices.