Pyloton: Rob ter Horst’s 100 smartwatches: If Rob ter Horst would build an Adafruit Pyloton, whould he not have the scientific tool which is helpful to show that only view scientists use PPG HRMs?: https://petergamma.org/category/optical-heart-rate-sensor Scince scientists at the highest level use preferentially 3 channel ECG devices: https://petergamma.org/category/ecg-devices