• Article

Mixed Messages: The Limitations of Fitness Trackers

Consumers have to be wary of the accuracy of fitness trackers as well as how the information that’s collected by the manufacturer is used. We also wonder whether smart watches will make such devices obsolete in the years ahead.

Email to a Friend


It’s no mystery why fitness trackers appeal to gadget-gobbling consumers. Who wouldn’t be enticed to wear a wristband-size device that’s designed to monitor and analyze—to paraphrase Sting—every step that you take and every move that you make? If you run, work out at a health club or just take the stairs at work to stay healthy or to shed a few pounds, then it’s easy to understand why you’d buy a fitness tracker. The device is marketed by manufacturers as a combination coach/cheerleader/analyst for your fitness goals.

In the 12 months that preceded April 2014, sales of fitness trackers generated $362 million in revenue, says Ben Arnold, who is an analyst at market-research company The NPD Group. Arnold estimates that revenue that’s generated by fitness tracker sales could grow by 75 percent in 2014 from the previous year. At press time, we found 30 fitness trackers that were on the market, and at least seven other models are expected to arrive before the end of 2014, according to manufacturers.

However, plenty of evidence suggests that fitness trackers aren’t a good fit for everyone. Studies indicate that fitness trackers might deliver an inaccurate analysis of your performance, which means that the 230 calories that the device reports that you just burned might be more like 200 calories. Concerns also exist over how the information that fitness trackers collect might be used against you.

Finally, we believe that the emergence of so-called smart watches, which deliver more features and capabilities than do fitness trackers, has the potential to make fitness trackers obsolete in the years ahead or at least could give you a case of fitness tracker envy. For instance, in April 2014, reports emerged that Nike no longer would make its FuelBand fitness trackers, which fueled speculation that the company would join Apple’s efforts to produce a smart watch.

BODY BASICS. Fitness trackers monitor your activity via an accelerometer that’s inside of the device. An accelerometer is the same component that adjusts the orientation of your smartphone screen and allows wireless video-game controllers to communicate the movements that you make.

Click chart above to view full presentation

Click chart above to view full presentation

Simply put, an accelerometer that’s used in a fitness tracker measures the speed and direction of your movements. The most expensive fitness trackers use the data that the accelerometer collects and analyze the data through a free mobile application that’s on your smartphone or tablet computer or on a website.

Fitness trackers can be worn as wristbands, clipped onto belts or fastened to shoes. In general, you can expect to pay $50–$300 for a fitness tracker. The least expensive models typically count the number of steps that you take in a day, measure the distance that you walk or run and estimate the number of calories that you burn during your activities. The most expensive models add features such as monitoring your heart rate, your blood pressure and the quality of your sleep. Jawbone’s UP24 ($150) has a built-in silent alarm that wakes you by vibrating rather than by noise, so you won’t disturb your partner. The app for Fitbit’s fitness trackers sends a push notification to your smartphone that alerts you to a goal that you soon might attain, such as steps in a day or 100,000 steps overall.

However, you should know that free apps exist for your smartphone that can deliver the same basic features that exist on the least expensive fitness trackers, such as step count and distance measurement. The downside to such apps is that they have to be turned on at all times. Furthermore, certain apps require GPS to stay on, which means that the app will drain your smartphone’s battery.

Back to Article