We all love our wearables—so much so that those little activity trackers were named the Biggest Fitness Trend of 2016. But we should start taking the data regarding how many calories our tracker says we've burned with a big grain of salt, according to a new report. (Are You Being Fooled By Your Fitness Tracker?
Researchers at the Human Performance Laboratory at Ball State University in Indiana looked at how accurate trackers like Fitbit and Jawbone actually are. And they found that although they're pretty spot-on when it comes to tracking our steps, there's some major discrepancies when it comes to counting the calories burned during different physical activities.
To test out how popular wearables really stack up against research-grade measurement tools, the researchers had 30 healthy adults perform 10 different physical activities, including exercises like jogging and everyday activities like vacuuming. They tracked the participants' progress during all the activities using five different methods: a portable metabolic analyzer (what researchers use in the lab to get a breath-by-breath analysis of how many calories you burn), two wrist trackers (the Fitbit Flex and Jawbone UP24), and two hip trackers (the Fitbit Zip and the Fitbit One).
There were some major discrepancies between trackers. Using the metabolic analyzer as the standard for accuracy, they found that the fitness trackers overestimated calories burned during exercises by anywhere from 16 to 40 percent, and underestimated the calories burned during everyday household activities by up to 34 percent. (Find out The Right Way to Use Your Fitness Tracker.)
According to the report, the only exercise outlier is cycling: All the fitness trackers underestimated the calories burned on the bike by 37 to 59 percent.
The researchers did find that these trackers do a solid job of measuring your steps accurately, which probably has to do with the fact that activities like walking and jogging have a well-defined motion in both your hips and arms where most trackers are worn.
But while you might use your Fitbit to log how many miles you walked while running errands around the city, the bottom line is they're not a reliable method for counting how many calories you've burned. And, really, it's not just about calories—How Much Exercise You Need Totally Depends on Your Goals.