Originally Posted by
datlas
If you REALLY want to go down a rabbit hole, get a WHOOP device. It tracks HRV (heart rate variability). My cardiology EP friends tell me this is no way ready for prime time, btw.
From what I hear, no optical device can give really accurate R-R intervals. I use an old Polar chest strap for HRV and an optical device on the bike. The processing side of WHOOP sounds to me like expensive voodoo.