How accurate are fitness trackers?

It isn’t a scarf, a particular necklace, clip or even her favorite shoes. When Bridget leaves the house, the one fashion accessory she’s always sporting is a bracelet. Like most of her preferences, this part of a set of jewelry makes a statement. But it’s almost certainly not the statement you’re thinking.

Bridget’s bracelet is actually a fitness tracker affixed to a band of rubber, and she never leaves residence without it. In fact, she sleeps with it on and wears it around the house, while she walks her dog and when she works out at the gym. It also tracks her activity levels, including the number of steps she takes, the amount of sleep she gets and the amount of calories she consumes. Then it syncs the information with an app on her smartphone, let Bridget know whether she’s reached her goals. And most of the time, she does.

But does she really? What if all those thoroughly recorded steps and snacks are actually wrong?

A research conducted by a researcher at the University of Arizona found several fitness trackers were untrustworthy when it came to measuring energy disbursement. The study’s participants busy in a variety of activities whereas wearing fitness trackers, standing, including cleaning a kitchen, walking on a treadmill, playing a board game and typing. While the devices they wore exact activity levels when participants walked rapidly, these same devices were astonishingly bad at calculating the energy costs of cleaning, standing and other light activities. In general, the devices vastly underestimated the energy uttered and calories burned

Likewise, a study by Iowa State University researchers found fitness trackers were often imprecise. After 30 men and 30 women wore eight dissimilar fitness trackers for an hour-plus workout, including 13 dissimilar activities ranging from tennis to running; researchers exposed several inaccuracies among the models that led, in some cases, to a more than 23 percent rate of error which is not much bad for fitness tracker. Across the board, the fitness trackers performed best when capturing rapid aerobic activity, such as walking or jogging, as opposite to light activity or resistance exercises. And the more accurately the devices familiar activity, the more accurately they measured calories.

These inaccuracies matter for people relying on fitness trackers to increase their levels of physical activity. The worry is that some people may, for example, become depressed after failing to meet a tracker’s built-in goals when their activity levels might’ve been on similarity all along. Conversely, people who are overweight are flat to overestimating the amount of energy they expend. Then add a fitness tracker that is either under- or overestimating the activity they are actually doing, and there is plenty of room for poor results.