Battle of the Fitness Trackers: Which One Is Most Accurate?

Image: (Creative Commons)

Fitness trackers and pedometers don’t motivate everybody, but if you’re the kind of person who enjoys setting specific daily movement goals and hates seeing failure staring you in the face in the form of a low number, they can do wonders. Stanford researchers analyzed 26 studies on the devices and concluded that “the use of a pedometer is associated with significant increases in physical activity and significant decreases in body mass index and blood pressure.” But if you want to stay motivated, which option do you choose? Nike FuelBand? FitBit? Jawbone? How about one of those apps for your iPhone or Galaxy? Researchers from the University of Pennsylvania asked volunteers to wear a ridiculous number of devices while walking on a treadmill to determine which option is the most accurate. Their results, recently published in The Journal of the American Medical Association, are a bit surprising.

First of all, let’s look at the methodology. When we said a “ridiculous number of devices,” we weren’t kidding. On their waistband, each participant wore the Digi-Walker SW-200 pedometer and two accelerometers: the Fitbit Zip and Fitbit One. On their wrist, they were each sporting the Fitbit Flex, Jawbone UP24, and Nike FuelBand. Participants also had an iPhone in one pocket running three apps (Fitbit, Health Mate, and Moves) and a Galaxy S4 in the other pocket running Moves. It really is a wonder they weren’t too weighed down to walk at all with all of the accoutrements dangling from their person. They walked on a treadmill for 500 steps and 1,500 steps while a research assistant had the glamorous and no-doubt-thrilling job of counting their steps.

Base image via Poppet With a Camera (Creative Commons)

Base image via Poppet With a Camera (Creative Commons)

Now, the results: It may come as a surprise, but the pricey fitness trackers in the study were not that much more accurate than an inexpensive app you can put on your existing phone. And in the case of the $79 Nike FuelBand, which recorded about 20 percent fewer steps than it should have, the apps were significantly more accurate.

Pedometers worn on the waist did the best job of tracking, followed by apps carried in the pocket, and wrist trackers were the least accurate, which makes sense when you think about how your body moves when you walk or run. I did some kettlebell swings this morning that my wrist tracker was counting as steps, for example.

Of the three Fitbit options, the Flex was the least accurate (because it’s the one worn on the wrist). The Fitbit One and Fitbit Zip were the most accurate overall, followed by the Digi-Walker, the Jawbone, the Flex and all of the apps, and finally, the Nike FuelBand, which was counting steps about as well as a toddler or drunk dude. On the bright side, the FuelBand was underestimating steps, so perhaps wearing it would just make you work harder; it’s better than having a false sense of accomplishment.

So why would you not just select the most accurate option and move on? Because different things work for different people, and each option has its pros and cons:


Pros: They’re the cheapest option. They’re also something you’re carrying anyway, and fairly accurate.
Cons: Your battery life is going to take a beating.

Waistband Trackers

Pros: The most accurate of all the trackers.
Cons: Easy to forget because they have to be put onto your clothes each day. Also, easy to leave on your clothes and put through the washing machine (or maybe that’s just me?… I’ve done that twice).

Wrist Trackers

Pros: Put it on your wrist and forget it. You’re not going to put this baby though the washer unless you’re into some really weird stuff.
Cons: The least accurate of the trackers.

Do you use a fitness tracker? Are you happy with its accuracy? Tell us in the comments.