Fitness trackers: are they accurate? - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

Fitness trackers: are they accurate?

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UNITED STATES - Millions of Americans wear wristband fitness trackers to monitor their exercise and health. But are they accurate?

Yes and no, according to a new study from Stanford University.

Researchers tested seven brands of fitness trackers on a group of 60 volunteers as they worked out. Six of the devices accurately measured heart rate; however, none of them measured the number of calories burned correctly. Even the most accurate device was off by 27 percent, and the least accurate was off by 93 percent.

The devices tested were the Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, Pulseon, and Samsung Gear S2.