Train Fitness uses the motion of your Apple Watch to predict what exercise you are doing. It is crucial that these settings match how you actually wear your Apple Watch for auto-detection to function properly.
A mismatch of Digital Crown Orientation settings and actual orientation will cause auto-detection to fail.
How to Update Watch Orientation
If you’re unsure whether your current Apple Watch orientation settings match how you wear your watch:
Open the Settings app on your Apple Watch.
Go to General > Orientation.
You can also open the Apple Watch app on your iPhone, tap My Watch, then go to General > Watch Orientation.
