Unfortunately, these wearable fitness devices won't accurately count your steps. How accurate are physical activity trackers? We found out how they are measured by monitoring your heart rate, steps walked and calories burned. Many of us don't get enough exercise and turn to fitness trackers to help us monitor our progress. But how accurate are physical activity trackers? Fortunately, there is a wealth of research to help you find out, and we've looked at the most recent ones.
But how accurate are fitness trackers to measure your heart rate and help you enter cardiovascular heart rate zones? Some trackers allow you to add information about your height, weight, age and gender, which the device uses to calculate the basal metabolic rate, basically, how many calories your body burns each day in its normal functions. This is one of the reasons why Google reviewed its Google Fit application last year, to move away from arbitrary health goals, such as 10,000 steps. When your fitness band interprets data from its motion sensors, it is supposed to ignore movements that are not associated with walking. Previous-generation fitness trackers came with a chest band to measure heart rate by tracking electrical signals in the body.
This is really what differentiates one manufacturer from the other in the way they use tracker data. Accelerometers use electromagnetic sensors to detect movement, and fitness trackers interpret that information using an algorithm that trains devices to recognize what counts as a step. In short, what you do will affect the accuracy of your tracker when estimating the TEE, even if you have one of the best Fitbits (opens in a new tab). Most trackers use three-axis accelerometers to monitor arm movement in all directions, which can be freely translated into steps.
Participants were instructed to find ways to intentionally “trick” the trackers (for example, by shaking a phone while they were seated to let the tracker detect that they were walking). And considering the uncertain accuracy of devices across demographics, anyone considering using commercial fitness trackers to monitor health or compare people's performance should think twice. The researchers' tests are said to have measured the amount of oxygen used by a volunteer with an oxygen monitor during ten-minute walking and running sessions on a treadmill, after which the data were compared to various fitness trackers. The most popular activity trackers and smartwatches (such as Apple products, Amazfit, Coros, Fitbit, Garmin, Honor, Huawei, Polar, Samsung, Suunto, Withings, and Xiaomi) use an accelerometer to detect movement.
But dark-skinned users who have tried Fitbits and other trackers have complained that the devices give strange readings or don't work at all. Unfortunately, a new study by a team at the University of Aberystwyth has found that popular brands of fitness trackers are overestimating the number of calories burned by more than 50 percent. But, assuming that the TEE is still a valid measurement, any fitness tracker must accurately assess your activity level in order to calculate it.