Why doesn't the Apple Watch activity app count the activity recorded on the iPhone? When walking around with the iPhone and not the Apple Watch the iPhone records steps. However when looking at the Apple Watch activity app the previously recorded steps are not shown there. Why is that?
The activity recorded on the Apple Watch is separate from the activity recorded on the iPhone. As such each is recorded as a separate source in health.app. Also only activity recorded on the Apple Watch is reflected in activity.app.

Source: @pbur - Apple Software Engineer

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