Does the Apple Watch Activity app pull data from the iPhone Health app? Or is it only one way data stream with the Apple Watch uploading data into the Health app?

The two do not synchronize. The transfer is one way, from the watch to the phone. The Health app is smart enough to avoid duplicating steps if you're both wearing the watch and carrying the phone, but you will not see steps taken while not wearing the watch in the watch's fitness app or reflected on the watch itself.

Jacqueline Ramsay wrote:

Why is that .. other items reflect the same moving and standing match???

Not consistent??

The only data source for Move and Stand tracking is your Apple Watch, so the same figures are reported in the Health app on your iPhone as in the Activity app on your watch.

Go into the Activity app on the iPhone. Doing that will usually trigger the synchronization to the Health app.

Tim is correct - one way only

Why is that as the health app then has different numbers. Phone says 25,000 steps when not wearing the watch but other items reflect the same moving and standing match???

Not consistent??