Is your fitness tracker overestimating your workout?

False readings
Is your fitness tracker overestimating your workout?

How many steps did you take today? What was your average heart rate? And how well did you sleep? If you know the answer to these questions, chances are you are one of the millions of Americans using a fitness tracker. While this technology is incredibly popular, a new study says they are not incredibly accurate.

Iowa State University researchers found that these devices are between 15 to 40 percent off in determining the amount of calories burned by those wearing them. Over 50 adults wore all seven trackers at the same time and participated in 20 minutes of sedentary activity, 25 minutes of aerobic activity and 25 minutes of resistance training with a five minute break between each activity. The calories burned according to each fitness tracker was compared to the actual calories burned which was measure by breath monitoring system which has been proven to be accurate.

The most accurate trackers were the BodyMedia Core and Fitbit Flex, however they were off by 15 percent. These were followed by Jawbow, Actigraph, Nike, Misfit Shine and the Polar Loop which was 40 percent off of the actual measurement.

Gregory Welk, lead study author, encouraged buyers to be more educated about the accuracy of the various trackers available. “People buy these activity monitors assuming they work, but some of them are not that accurate or have never been tested before,” Welk said in a statement. “These companies just produce a nice-looking device with a fancy display and people buy it.”

This study does not mean that you should stop using your fitness tracker as they can be great motivational tools. In fact, Colleen Eggers, of the Good Samaritan Health and Wellness Center in Downers Grove, Ill., believes that wearing her fitness tracker is helping her to reach her health and fitness goals in 2015.

“I use my Fitbit every day to keep me motivated and on track,” Eggers says. “I make a conscience effort to enter my food every day and keep track of my work outs. It has helped me to be accountable.”

Eggers does caution that when a workout is entered manually into a fitness track the calories burned may be for the average person. However by also wearing a heart rate monitor that tracks calories you can manually enter the calories you burn into the tracker so that you have a more accurate number.