Health Check. 

Problem 3. 

Your Watch isn’t sending any health data to iPhone, or, the app has no permissions to read it. 

A) First check the following: 

Common Reasons for No Data Synch

1. Is bluetooth turned on? Some people accidentally turn it off. It’s easy to do. 
2. Are either of the devices in flight mode?
3. Did the Watch go into low power mode (< 10% battery)? 
4. Do you have a passcode on your Watch? This is required for background heart rate data. 
5. In Passcode in the Apple Watch settings app have you turned on Wrist Detection? This is required for background heart rate. 
6. In Privacy in the Apple Watch settings app, both Heart Rate & Fitness Tracking need to be turned on. 
7. Do you have a prominent wrist tattoo?

B) If all the above are ok then: 

Reset Permissions

To reset HealthKit permissions and iOS and Watch health services and ensure everything works on the watch going forward, please perform these steps. It is important to do all steps in this exact order especially step 2 as this restarts the crashed system services on your iPhone and Watch. 

1. Go into the iPhone Settings, Privacy, Health. Press AutoSleep and then press all categories off.
2. Power the iPhone off as per this link. (i.e. Shut the iPhone down completely so that it restarts with the  on screen).
3. Now in iPhone Settings, Privacy, Health, AutoSleep press all categories on. Make sure that all the switches are turned on. 
4. Now go into AutoSleep iPhone app and this should restore all permissions