The steps to open permissions are as follows:
Open iphone and look for settings.
Find "Privacy" under the Settings page.
Find "Sports and Fitness" under the privacy page.
We see that "Fitness Tracking" under the "Sports and Fitness" page is off, now we turn it on.
reference data
What if there is no data in the health display of iPhone6 and iPhone6 Plus? Baidu experience [reference time 20 17- 12-23]