Some of that problem is inherent to the design. Reflective PPG just doesn't work great, especially when you're wiggling it around everywhere. There's a whole b

Some of that problem is inherent to the design. Reflective PPG just doesn't work great, especially when you're wiggling it around everywhere. There's a whole bunch of signal processing mumbo-jumbo you can do to get a clean-ish heart rate from reflective PPG, it's just more complicated than Samsung/Apple/etc probably care to implement. They're selling you a watch, not a medical device. It sucks, but that's advertising.