Solution:
PAI can be viewed on the band or the APP. To use the PAI function, please turn on automatic heart rate detection and set the frequency to 1 minute.
Setting Path：
1.Mi Fit APP：My->Mi Band->heart rate detection->Automatic heart rate detection -> set the detection frequency
2.Mi Wear APP：Device->Additional setting->heart rate detection->Automatic heart rate detection -> set the detection frequency
View Path:
1. Enter the PAI page or slide on the main page to switch to the PAI card and enter the PAI details page to view the current PAI and the range of PAI. Slide up to view the PAI trend in the past 7 days.
2. Mi Fit APP-> home page ->PAI, click to view the PAI value of the last seven days.
3. Mi Wear App-> Data->PAI, click to view the PAI value of the last seven days, there are some related introduction about PAI.