Researchers from the University of Mississippi analyzed 56 test results of Apple Watch smartwatches for the reliability of fitness activity measurements. As it turned out, sometimes the gadget seriously “lies,” and it is impossible to rely on it when it comes to losing or gaining weight.
The study compared the Apple Watch with specialized tools for analyzing health and physical activity indicators: heart rate monitors, pedometers, and equipment that measures the number of calories burned. It turned out that the smartwatch counts steps and heart rate well: the average absolute percentage deviation from the readings of the reference devices was 8.17% and 4.43%, respectively.
But the Apple Watch fared much worse when it came to measuring calories burned. The measurement error averaged 27.96% across all activities tested: cycling, running, moderate-intensity workouts, and walking.
“These devices are great for tracking habits and staying motivated. But don’t take every number they give you as gospel, especially when it comes to calories. Think of them as helpful guidelines, not diagnostic tools. They’re helpful, but they’re not perfect,” the researchers said.
Scientists also noted that the measurement accuracy of wearable electronics is gradually increasing, but it is still low compared to specialized devices.