Units that monitor our coronary heart charges primarily based 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 corresponding to coronary heart price variability from Whoop. These units then inform us insightful issues about our current exercises or our exercise all through the day, how lengthy we must always get well earlier than our subsequent exhausting exercise, and even how nicely we’re sleeping.
The difficulty is that the accuracy of the information all this info is predicated on is suspect. I first seen this again once I had a Fitbit. It might typically learn increased than I suspected was right, primarily based on how exhausting I felt I used to be working. The identical is now true of my Garmin watch. I may be simply warming up, and it’ll inform me my coronary heart price 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 not too long ago put it to a check. I occur to even have a Polar H10 coronary heart price strap. And a separate gadget (my Garmin bike pc). So on the identical trip, I made certain my watch was not paired to the strap, and solely had wrist information out there for coronary heart price. 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 trip are proven under. The max coronary heart price from the wrist measurement was 41 beats two excessive, and suspiciously confirmed up once 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 primarily based on coronary heart price, 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 be certain I exploit the strap once I actually wish to test coronary heart price. I may even put extra belief in how my exercise feels (perceived degree of exertion).