Many leading brands of smartwatch are outright lying to users about resting heart rate, providing us with misleading numbers that make us seem far fitter than we actually are. So I decided to get to the bottom of these resting heart fakes, with a bit of help from YouTube’s Dr @MedlifeCrisis.

You might also enjoy the previous video in this series, in which Rohin and I discuss the most important number for your health:    • The most important number for your he...  


Chapters

00:00 Introduction
01:59 Dropping some beats
03:17 Am I crazysuperfit?!
04:18 Why lie?
06:47 Sleeping heart rate


Sources and further reading

Sleeping vs resting heart rate in 11 teenage athletes https://journals.plos.org/plosone/art...
The study I mention comparing the resting and sleeping heart rate for predicting allcause mortality https://academic.oup.com/eurheartj/ar...

Links at which various manufacturers state how their ‘resting’ heart rate values are calculated:
• Apple Watch https://support.apple.com/enus/HT204666
• Garmin https://www.garmin.com/enGB/garmint... but I also found this page https://support.garmin.com/enUS/?faq... which states ‘Daily RHR is calculated using the lowest 30 minute average in a 24 hour period.’ Though this doesn’t specifically target when you’re asleep, the lowest 30minute average will almost certainly come from sleepytime…
• WHOOP https://www.whoop.com/thelocker/resti...
• Oura https://ouraring.com/blog/restinghea...
• Fitbit are supervague about this and don’t seem to have any official information about this. But I enjoyed a quote in this paper looking at Fitbit users’ resting heart rate data, which states audaciously that ‘RHR was calculated by a proprietary formula’. It’s kindof incredible to me that you can publish something so explicitly intransparent—especially in a journal like PLOS ONE that champions open science, open data and open code! https://journals.plos.org/plosone/art...


And finally…

Follow me on Twitter   / statto  
Follow me on Instagram   / andrewjsteele  
Like my page on Facebook   / drandrewsteele  
Follow me on Mastodon https://mas.to/@statto
Read my book, Ageless: The new science of getting older without getting old https://ageless.link/