[macNchz]

For a long time I was sort of baffled by the (bad) level-of-fitness and restedness metrics I was getting in a couple of popular apps.

At some point I decided to figure out what the deal was with it, and I saw that their calculations were based on resting heart rate, but because I only ever wear my Garmin running watch during actual runs, it was inferring my RHR from the lowest HR it picked up before or after my run, and reporting to every connected app that mine was like 120bpm (my real RHR is more like 50bpm). Everything was seemingly happy to just accept the garbage data and plug it into their formulas to produce garbage output. Really they probably should have just told me to see a doctor if they actually believed I had a 120bpm resting heart rate!

After that I turned off all of the automated metrics—it was a big realization about how easily messed up they can get (even if you wear your watch most of the day, you might have a fairly different RHR based on whether or not you sleep with it on). I can see this exact situation causing someone a lot of undue anxiety.