It seems their algorithm wouldn't work for me -- it would rate me falsely insulin insensitive:

  > " Google’s study found the expected pattern: HOMA-IR rose with resting heart rate (r = 0.27) and fell with daily steps (r = -0.25) and HRV (r = -0.14)."

I have unusual chronic sympathetic nervous system stimulation such that my RHR is +90 even during sleep and my HRV is 8-13ms, despite ~2hr daily exercise.

My actual HOMA-IR values were so low they were _below_ the reference range, the exact opposite of what this model would predict:

https://i.imgur.com/ISEwgAl.png