
Units that monitor our coronary heart charges based mostly on a measurement on the wrist are fairly prevalent these days, together with Fitbit, Garmin watches, and Apple Watches. There are additionally units that promise extra subtle outcomes reminiscent of coronary heart charge variability from Whoop. These units then inform us insightful issues about our latest exercises or our exercise all through the day, how lengthy we should always get better earlier than our subsequent laborious exercise, and even how effectively we’re sleeping.
The difficulty is that the accuracy of the information all this data is predicated on is suspect. I first seen this again after I had a Fitbit. It might usually learn larger than I suspected was right, based mostly on how laborious I felt I used to be working. The identical is now true of my Garmin watch. I will be simply warming up, and it’ll inform me my coronary heart charge is within the 130’s, which I do know can’t be true as a result of I’d actually be huffing and puffing. I just lately put it to a take a look at. I occur to even have a Polar H10 coronary heart charge strap. And a separate gadget (my Garmin bike pc). So on the identical journey, I made certain my watch was not paired to the strap, and solely had wrist knowledge out there for coronary heart charge. My bike pc was paired to the strap so it was a chest-based measurement. In such a comparability, we anticipate the chest measurement to be extra correct, however I used to be blown away how a lot the 2 differed. The 2 charts from a three-hour journey are proven under. The max coronary heart charge from the wrist measurement was 41 beats two excessive, and suspiciously confirmed up after I was simply warming up. There are numerous different locations within the charts the place the wrist outcomes are simply not proper.


I had been studying up on optimum coaching strategies based mostly on coronary heart charge, all of which sound fairly scientific. However I now know that the information I used to be basing this on was untrustworthy (I normally simply use wrist-based as a result of it’s an additional step to placed on the strap). Sooner or later I’ll ensure I exploit the strap after I actually wish to examine coronary heart charge. I can even put extra belief in how my exercise feels (perceived degree of exertion).