Do Fitness Trackers Actually Help You Get Fit? What the Science Says

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One in five Americans now owns a Fitbit, Garmin, Xiaomi, or other similar device, and we’re predicted to purchase 19 million of these gadgets in 2016 alone. Despite our love affair with wearable tech, whether these devices actually help us move more, get fitter, or drop pounds is a matter of debate. Until recently, there hadn’t been much proof. But now that scientists have had time to conduct longer, more in-depth studies, the evidence is piling up. Let’s just say the latest findings probably aren’t making the folks at Fitbit do fist-pumps.

What the New Science Says

In September, JAMA published a two-year study from the University of Pittsburgh that suggested fitness trackers may actually undercut weight-loss efforts. For the first six months, 470 overweight adults followed a calorie-restricted diet, aimed for 100 minutes of moderate-intensity physical activity a week, and attended weekly group counseling sessions. As expected, everyone lost weight.

For the remaining 18 months, half of the participants got armband fitness trackers (the best tech available at the time) while the other half self-monitored their food intake and exercise. The researchers thought for sure the fitness tracker group would stick more closely to the weight-loss program and shed more pounds total.

In fact, the reverse happened. After two years, the fitness tracker group lost just 7.7 pounds while the self-monitoring participants nearly doubled that, losing 13 pounds.

A second new study, published in The Lancet Diabetes & Endocrinology, also showed that trackers didn’t help people move more — or get healthier. In this one-year trial, researchers at Duke-National University of Singapore Medical School challenged 800 workers to hit 70,000 steps a week. They gave one group Fitbit Zips and another group Zips plus a cash bonus each week they hit their step goals. The control group got nothing but old-fashioned encouragement to walk more.

At first, the money worked, but the Fitbits alone didn’t. The Fitbit-plus-cash group put in 29 more minutes of moderate physical activity a week than the control group (not bad), but the Fitbit-only group logged just a few more minutes per week than the control.

But then after six months, all incentives were wiped off the table. Nearly everyone’s efforts tanked. By the study’s end, 90 percent of the Fitbit users had abandoned their devices. The cash group actually regressed, taking fewer steps per day than they had before the study began. What’s more, nobody — tracker or no tracker — showed any measurable improvement in weight, blood pressure, aerobic fitness, or quality of life.

“Fitness trackers are equivalent to a bathroom scale,” says Eric Finkelstein, lead author of the Lancet study. “They tell you something but don’t give you a strategy for how to change it.”

What to Make of These Results

So what’s going on here? Researchers on both of these studies warn that we shouldn't jump to conclusions just yet.

“These findings don’t mean that fitness trackers don’t work,” says John Jakicic, lead author of the JAMA study. “They just don’t work for everybody. They’re marketed on the premise that if you see how little you’re doing physically, you’ll be motivated to do more, but that’s a very simplistic way to think about changing behavior. Many people need a lot more than that.”

That's a problem when consumers misperceive what are in fact data trackers as motivational tools. “Fitness trackers are equivalent to a bathroom scale,” says Eric Finkelstein, lead author of the Lancet study. “They’re a measurement tool, not an intervention tool. They tell you something, but don’t give you a strategy for how to change it.”

Dr. Mitesh Patel, a fitness tracker researcher from the University of Pennsylvania, likens these devices to gym memberships. “People pay a few hundred bucks to join a gym thinking it’ll engage them in new behaviors,” he says. “But beyond the first few weeks, most people don’t go. Similarly, giving someone a fitness tracker won’t change their behavior. It can help facilitate changes, but it won’t, by itself, drive change.” And that, he says, is a big reason why millions of trackers are now collecting dust in drawers across the nation.

"If you’re very committed to working out, and you’re really into numbers, these devices may be a big help."

Are You a "Quantified Selfer"?

From what is known so far, it’s becoming clear that those who do get a lot out of trackers share two main traits: They’re already motivated to exercise, and they dig data. Both factors are essential. “You could be a numbers person but not all that motivated to be active,” Patel says. “Or you could already be going to the gym five days a week but just not into numbers. However, if you’re very committed to working out, and you’re really into numbers, these devices may be a big help.”

These types of people, who Patel says are a small minority, have been dubbed “quantified selfers — already training, already going on frequent runs or rides, already working toward a goal such as a marathon,” he explains. “He has high levels of motivation and engagement to begin with.” When that inherent get-up-and-go is coupled with an interest in knowing and improving upon your numbers, Patel says there’s a decent chance a tracker will come in handy.

For now, quantified selfers may be the ones finding the most success with wearable devices, but even that could soon change. According to Patel, as tracker technology continues to improve and devices become easier to wear, operate, and glean info from, there will be more opportunities for more people to engage with their tracker.

“For instance, with many of the newer wrist trackers, you don’t have to charge the battery for six to eight months,” he says. “Many are now waterproof so you don’t have to take them off and put them back on every time you shower. Neither will matter if you’re not motivated to begin with, but as the tech gets better, that should improve compliance.”

Jakicic adds that as the tech evolves, trackers will begin offering various interfaces, programs, and functions that should resonate with a broader swath of users. “Right now, we’re not doing very well at helping people understand how to use the info provided by fitness trackers,” he says.

For now, however, “we definitely want to send the message that if a device is motivating you and you’re getting results, by all means keep using it,” Jakicic says. “Or, if [you're] struggling with your weight or with keeping active, and you think a device might be helpful, go ahead and give one a try.”