Hi
Some other users have reported experiencing similar issues when travelling at slower speeds via methods other than walking or running (for example: riding in golf carts, on mopeds or on horses).
It may help to calibrate your Apple Watch, which teaches your watch how your arm movements relate to walking or running at different speeds (this process can be equally as useful for Series 3 models):
Calibrating your Apple Watch for improved Workout and Activity accuracy - Apple Support
To delete unwanted Exercise Minutes:
- On your iPhone, in the Health app, go to: Health Data (tab) > Activity > Exercise Minutes > Show All Data > select the day.
- Swipe left on data points or tap on Edit (upper-right) to delete them.
If you would like to send feedback to Apple (you should not typically expect to receive a reply), then you can do so here:
Feedback - Apple Watch - Apple
If you would prefer to discuss the matter with Apple, then contact options include: