After my Apple Watch 1 I decided to switch to the Apple Watch 2 and gave my GF also an Apple Watch 2. The strange thing is: My green activity ring is filling during my day without starting a workout (just walking stairs etc) but my GF's watch barley updates the green ring.
Example: We are walking in the city next to each other. We both have around 2000 steps and walked 2K without a workout. My green ring is at 40%, hers is at 3%.
How is this possible? We set the same movement goals.