One Dirty Magazine

Ask the Coach: Wrist-Based Heart Rate: Yea or Nay?

Can I rely on a wrist-strap heart-rate monitor, or should I stick with a chest strap?

David Roche September 1st, 2017

Ask the Coach: Wrist-Based Heart Rate: Yea or Nay? Photo by Ross Comer.

Can I rely on a wrist-strap heart-rate monitor, or should I stick with a chest strap? 

—Maya, Los Angeles, CA


When it comes to monitoring the telltale heart, there are two options: chest-strap or wrist-based monitors. Unfortunately, wrist straps aren’t yet accurate enough to guide training.

In January 2017, a group of researchers from the Cleveland Clinic published a letter in the Journal of the American Medical Association Cardiology on the accuracy of wrist-based heart-rate monitors. The researchers had 50 adults use a chest-strap monitor and four different wrist-strap monitors while exercising on a treadmill set to 2 mph, 3 mph, 4 mph, 5 mph and 6 mph. Researchers compared the heart-rate monitor readings against an electrocardiograph (a medical-grade heart-rate monitor used in hospitals). The chest-strap readings had a 0.99 correlation with the electrocardiograph readings.  But the wrist straps told a different tale.

The four wrist straps varied between a dismal 0.83 and 0.91 correlation, with higher variation during activity. Sometimes, heart rate varied by as much as 40 beats per minute.

So the technology is exciting, but if you train with heart rate, it’s not time to jettison your chest strap quite yet. If Edgar Allen Poe had had a wrist-strap heart-rate monitor when he wrote his famous story, it might have ended nine- to 17-percent differently.



Have questions for Coach Roche? Send them to [email protected]


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Tripp KnightlyStevemy nameKen Recent comment authors
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Looks like Trail Runner didn’t want to alienate potential advertisers:
Each participant was randomly assigned to wear 2 different wrist-worn HR monitors. Four wrist-worn monitors were assessed: Fitbit Charge HR (Fitbit), Apple Watch (Apple), Mio Alpha (Mio Global), and Basis Peak (Basis)….
The Apple Watch and Mio Fuse had 95 percent of differences fall within -27 beats per minute (bpm) and +29 bpm of the electrocardiogram, while Fitbit Charge HR had 95 percent of values within -34 bpm and +39 bpm and the corresponding values for the Basis Peak were within -39 bpm and +33 bpm.
Full article:

my name
my name

And those ranges are all *horrible* compared to the EKG numbers. That’s why they said that wrist-based is not yet ready for heart-rate training, on any of these… 🙂


I use a Garmin, and generally find the numbers useful, although if I have the GPS function turned off, the heart rate numbers make no sense. It once showed me at max heart rate during a very slow jog; then when I ran the last couple of miles home at 5k pace, it showed the same heart rate. It also underestimates my night time resting heart rate.

Tripp Knightly
Tripp Knightly

The article talks about the 95% range for differences but I think that’s not very interesting or relevant to me. What I’d rather see is how correlated the measurements are, and are the mean measurements within 95% of each other. So what if the wrist monitoring flakes a bit because they are more prone to movement than electrical-based and so are understandably more volatile than the EKG gold standard? I find the measurements I’m getting from my Mio useful. I’d take that over the bondage of the chest strap.