Do you trust your Fitbit so much that you base many of your weight loss choices on the readings it gives you? After learning about the results of yet another major study suggesting that these fitness trackers aren’t very accurate, you may find yourself changing your mind.
To start, it should be noted that the company behind the gadget does tell you that you can trust your Fitbit as a type of tool to give you overall guidance. That said, it does not suggest that it is 100 percent accurate, nor does it equate itself with the precision of medical tools. It is meant to provide you with some general feedback so you can better understand the trends in your activity and calorie intake.
Still, problems arise if you trust your Fitbit readings too much. If you look at what the device tells you in terms of the number of calories you’ve burned and then decide how much you should eat based on those numbers, you may not be doing yourself any favors. Like the treadmill at your gym, the calorie burn estimate may not be anywhere near what’s really going on in your body.
The study was conducted by the Stanford University School of Medicine and examined a number of the most popular fitness trackers. This included the Fitbit Surge, as well as the Apple Watch, PulseOn, Samsung Gear 2, Microsoft Band and Basis Peak. The accuracy of each device was measured and compared.
The fitness bands were used on a group of volunteers that either used treadmills or stationary bikes while hooked up to an electrocardiograph (ECG).
Each of the fitness trackers were good enough at reading the wearer’s heart rate that they beat the estimates of the researchers. Though they predicted a 10 percent margin of error, the true margin was only 5 percent.
That said, none of the devices provided an accurate calorie burning estimate during exercise. In fact, Euan Ashley, senior author of the study and Stanford professor of cardiovascular medicine, genetics and biomedical data said that they were all “way off the mark.”
Just as the researchers were surprised by the accuracy of the heart rate monitor features, they were also surprised by the lack of accuracy when it came to calorie burning. The worst was the Samsung Gear 2, which had a margin of error of a tremendous 93 percent. The apple watch was the most accurate but was still off the mark by a sizeable 27 percent.