This topic has been raised at least two dozen times here and on the Apple forums, but I haven't found a conclusive answer. I've read the "multiple source" help page from Apple, but this particular situation as I experience it isn't really addressed. In the health app, movement data is collected from both devices. For example, yesterday, I logged 5.5 miles of distance walked. In the "Walking + Running Distance" segment of the app, I can click "Show All Data", then click on the 30 January entry. This will show the breakdown, which includes data collected from both devices, shown in the photo below. Is the app combining the data from both sources? Is there a way for it to collect data from the phone only when I'm not wearing the watch?