That's an interesting assessment I was curious about this and curious if the measurements made by my smart watch were "good" or "bad", and it does calculate RM

That's an interesting assessment I was curious about this and curious if the measurements made by my smart watch were "good" or "bad", and it does calculate RMSSD (allegedly) Though it seems while they have some correlation they're all over the place https://www.researchgate.net/figure/Scatterplot-for-SDNN-A-B-RMSSD-C-D-pNN50-E-F-and-HFnu-G-H-for-men-left_fig1_311620117 https://www.researchgate.net/figure/Scatterplot-for-SDNN-A-B... SDNN also might apply to a different time range than RMSSD