Physical activity trackers are out of place when measuring calories, research says The Guardian. An independent analysis of several leading brands found that all were prone to imprecisely recording energy expenditure. Ball State researchers concluded that activity trackers are not accurate enough to reliably determine calories burned. Study participants used the physical activity trackers while walking or running on a treadmill and pedaling on an exercise bike.
The damning report concludes that the trackers are not accurate enough to be used in sports activities or in health care. The machines don't take into account your fitness level or if you lean on the handlebars or do something else that makes training easier and ultimately impacts calorie burning. There have been several different studies that show that fitness trackers and smartwatches are quite good at measuring heart rate at rest or in recovery, but are less accurate as exercise intensity increases. Technological advances made in the late 20th and early 21st centuries led to the creation of devices that automate the ability to monitor and record fitness activities.
Algorithms are likely making assumptions that don't fit people very well, Shcherbina said. You need to pair most of these devices, such as the Fitbit Inspire 2, with a compatible app in order to fully access your data. Researchers used a sample of 50 people and measured their heart rate with physical activity trackers while walking and running on the treadmill. Portable fitness trackers with calorie burned counters, such as those on Apple Watch and Fitbit, can be a great motivation to exercise.
On the other hand, most monitors underestimated calories burned through household activities by up to 34% (except for Fitbit Flex), although wrist monitors were more reliable than those worn on the hip. The authors concluded that fitness devices are good enough for personal use, but they cannot be trusted in clinical or research settings. Manufacturers can extensively test the accuracy of activity devices, Ashley said, but it's difficult for consumers to know how accurate that information is or the process manufacturers used to test the devices. They found that the devices were accurate for heart rate, but “estimates of energy expenditure are poor and would have implications for people who use these devices to lose weight.
It turns out that the clock underestimated my total calorie burn during each exercise, but Slade tells me that I could overestimate for someone else. To test its accuracy for myself, I have come to Stanford University's human performance laboratory, filled to the brim with a range of sophisticated training equipment including an anti-gravity treadmill. Consumer Reports also uses heart rate monitor accuracy in its evaluation criteria for physical activity monitors, but does not include information on calorie burn.