My usual RHR is around 55. I didn't sleep well yesterday and it was shown in the morning by an elevated RHR (59). I slept well again today and RHR is back to 55. However, yesterday's RHR also got changed to 55, as if last night didn't happen at all. It seems that RHR calculation is influenced by the evening sleep. This is wrong. That belongs to the next day.
In my experience, the sleepStress data (average stress level during sleep time) would be a better indicator for sleep quality. But it is not visible in the interface and requires programming knowledge to find and extract it. Please show it in the stress charts along with awakeStress and totalStress.
Relatively bad sleep (sleepStress=16, worst I had is 25):
Relatively good sleep (sleepStress=11, best I had is 8):
