According to researchers at Stanford University, most fitness trackers can’t be relied on to accurately track number of calories burned. Here’s what happened:
Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn and Samsung Gear S2 were tested in a group of 60 people. The results showed that measuring heart rate had an error rate of less than 5% on 6 of the devices, while none of the devices were accurate when measuring energy expenditure. The most accurate device was incorrect by 27% on average while the least accurate was off by 93%.
Thirty-one women and 29 men volunteered to help test the accuracy of the devices. Each volunteer wore the 7 devices while walking or running on treadmills or while using stationary bikes. Their heart rates were measured using a medical-grade electrocardiograph and the metabolic rate was measured with an instrument that measured the oxygen and carbon dioxide in their breath. The researchers then compared the results from the actual medical devices to the fitness trackers.
“The heart rate measurements performed far better than we expected,” said Ashley. “But the energy expenditure measures were way off the mark. The magnitude of just how bad they were surprised me.”
Since each device uses its own custom algorithm for calculating energy expenditure, the researchers aren’t sure why the measurements are so wrong.
“All we can do is see how the devices perform against the gold-standard clinical measures,” Shcherbina said. “My take on this is that it’s very hard to train an algorithm that would be accurate across a wide variety of people because energy expenditure is variable based on someone’s fitness level, height and weight, etc.”
And that’s why any activity tracker that claims to tell you “resting calorie burn” or “metabolic rate” is just plain wrong. Luckily, Breezing’s Calorie Corrector is here to correct the numbers generated by activity trackers, bridging the gap between activity trackers’ estimates and true metabolic rate.
For more details on the Stanford study, follow this link: http://www.medicaldesignandoutsourcing.com/fitness-tracker-misleading-data/