I just got my instinct and my goal is to use it for 24/7 and eventually replace the need to check HRM (TICKR). Initially I was testing Instinct HRM in 24/7 mode and found the number is far from what my chest HRM told me, while I was riding on my bike on KICKR Snap with TICKR chest HRM via Ant+ (Golden Cheetah) . After testing it for an hour, I was so disappointed and ready to send it back.
Then toady I repeat the test but this time I enter the Activity (GPS>>bike indoor), and I found now the Instinct HRM agrees with TICKR HRM very well now. So my theory was that either Instinct HRM in its 24/7 mode has much less sampling points so the accuracy was way low, or there is algorithm/filtering behind the raw data so that the change of heart rate has been low-pass filtered (so that 24/7 HRM cannot see rapid heart change).
I would like to check if others have observed the same behavior.
(And I know the limitation of optical HRM vs chest, and most people has problem in Activity instead of 24/7, etc...)
Thanks!