![Fitness trackers aren't very accurate at measuring heart rate — and that can be dangerous - The Verge Fitness trackers aren't very accurate at measuring heart rate — and that can be dangerous - The Verge](https://cdn.vox-cdn.com/thumbor/9SFSNq_EQEEfMH5w8sWubWmjqc0=/0x0:2040x1360/1400x1400/filters:focal(1020x680:1021x681)/cdn3.vox-cdn.com/uploads/chorus_asset/file/2447680/DSCF5750.0.jpg)
Fitness trackers aren't very accurate at measuring heart rate — and that can be dangerous - The Verge
![Amazon.com: Fitbit Charge HR Wireless Activity Wristband (Plum, Large (6.2 - 7.6 in)) : Sports & Outdoors Amazon.com: Fitbit Charge HR Wireless Activity Wristband (Plum, Large (6.2 - 7.6 in)) : Sports & Outdoors](https://m.media-amazon.com/images/W/IMAGERENDERING_521856-T2/images/I/41A0dHGEXyL.jpg)
Amazon.com: Fitbit Charge HR Wireless Activity Wristband (Plum, Large (6.2 - 7.6 in)) : Sports & Outdoors
![A few quick thoughts on Fitbit's new activity trackers, GPS watch (with optical heart rate!) | DC Rainmaker A few quick thoughts on Fitbit's new activity trackers, GPS watch (with optical heart rate!) | DC Rainmaker](https://media.dcrainmaker.com/images/2014/10/Fitbit-New-Products-Image.png)
A few quick thoughts on Fitbit's new activity trackers, GPS watch (with optical heart rate!) | DC Rainmaker
![A few quick thoughts on Fitbit's new activity trackers, GPS watch (with optical heart rate!) | DC Rainmaker A few quick thoughts on Fitbit's new activity trackers, GPS watch (with optical heart rate!) | DC Rainmaker](https://media.dcrainmaker.com/images/2014/10/image_thumb45.png)