From Fitbits and Apple Watches to Microsoft Bands and Mio Alphas, the range of fitness trackers on the market has exploded as we trust them with our health and fitness goals. Owners of these devices are deciding what to eat, how much to exercise and even how much water to drink, based on the data provided to them without a second thought. But, as these consumer devices aren’t held to the same standard as medical-grade devices, this could present a problem.
Recent research from the Stanford University Medical Centre, has exposed the accuracy of devices when measuring heart rate and calories burned showing that some can be off by nearly 100%.
Researchers evaluated the biggest brands in fitness trackers, uncovering that there are many factors that contribute to the accuracy of the devices. Body mass index and, surprisingly, skin colour were amongst the biggest factors that affected the measurements.
The good news is, the majority of devices tested were able to measure heart rate with less that 5% error. Your workouts are safe.
The bad news – none of the tested devices were able to measure energy expenditure accurately. If you’re one of the many that uses a wearable device to base your weight loss goals on calories burned through exercise, then it might be time to reevaluate. The most accurate device in the study was off by 27%, and the least accurate by a massive 97%.
The results are worrisome for those whose weight and fitness is adversely affecting their health. With an unspoken trust between user and device, many other contributing factors to physical health are overlooked. What’s more, it’s hard for doctors to know what to make of the data collected from a patient’s wearable device.
Fitness trackers have proven to be great motivation for a healthier lifestyle. But next time you head out for a run, consider taking the data with a grain of salt.
Sarah Condie is a freelance writer based in Melbourne.
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