Science Says Fitness Trackers Don't Work. Wear One Anyway

Activity monitors are getting more addictive—and more motivational.
fitbit

Personal technology is getting a bad rap these days. It keeps getting more addictive: Notifications keep us glued to our phones. Autoplaying episodes lure us into Netflix binges. Social awareness cues—like the "seen-by" list on Instagram Stories—enslave us to obsessive, ouroboric usage patterns. (Blink twice if you've ever closed Instagram, only to re-open it reflexively.) Our devices, apps, and platforms, experts increasingly warn, have been engineered to capture our attention and ingrain habits that are (it seems self evident) less than healthy.

Unless, that is, you're talking about fitness trackers. For years, the problem with Fitbits, Garmins, Apple Watches, and their ilk has been that they aren't addictive enough. About one third of people who buy fitness trackers stop using them within six months, and more than half eventually abandon them altogether.

As for that guy at work whose Fitbit appears to be bionically integrated with his wrist, it's unclear whether wearing the thing actually makes him more fit. Most studies on the effectiveness of fitness trackers have produced weak or inconclusive findings (blame short investigation windows and small, homogenous sample sizes). In fact, two of the most well-designed studies to date have turned up less than stellar results.

The first, a randomized controlled trial involving 800 test subjects, was conducted between June, 2013 and August, 2014. The results, which were published lastyear in The Lancet Diabetes & Endocrinology, found that, after one year of use, a clip-on activity tracker had no effect on test subjects' overall health and fitness—even when it was combined with a financial incentive. (In a perverse twist, volunteers whose incentives were removed six months into the study fared worse, in the long run, than those who were never offered them at all.) The second, an RCT out of the University of Pittsburgh conducted between October 2010 and October 2012, examined whether combining a weight loss program with a fitness tracker, worn on the upper arm, could help test subjects lose more weight or improve their overall health. The results, published last year in the Journal of the American Medical Association, showed that subjects without fitness trackers lost more weight than their gadget-wearing counterparts—a difference of about eight pounds. And while it's true that weight is not a great proxy for health, the findings also showed that the test subjects with fitness trackers were no more active or fit than those without.

All of which is, frankly, pretty embarrassing for companies that manufacture fitness devices—not to mention disquieting for the people who wear them.

And yet, none of this means you should ditch your fancy new fitness tracker. Have companies like Fitbit and Garmin been slow to incorporate sticky features into their products? Yes. Unequivocally. By 2013—the year Apple brought attention-enslaving push notifications to its phones’ lock screens, and around the time the Lancet study was getting off the ground—fitness trackers and their accompanying apps had only just begun to leverage theories from psychology and behavioral economics. But today's products are different.

The fact is, most existing studies on fitness trackers—including the two I cited above—hinge on devices that are several years old. (Think glorified pedometers that don't connect seamlessly with the supercomputer in your pocket.) And while peer-reviewed research on the latest wave of workout gadgets is still sparse, signs suggest newer wearables are finally becoming more addictive.

For starters, wearable fitness trackers themselves have turned into wildly capable machines. It's no longer enough to measure steps and active minutes; features like sleep-tracking and 24/7 heart rate monitoring have also become table stakes. So, too, have the beefy batteries necessary to make features like continuous heart-rate detection worth a damn. Fitbit's newest "motivating timepiece," the Ionic, can go four days between charges. The Fenix 5, Garmin's flagship fitness watch, can last up to two weeks.

"If it's comfortable, it's waterproof, the display's always readable, and it's got a long battery life, there's less excuse for people to take it off," says Phil McClendon, Garmin's lead product manager. For technology companies, few metrics matter more than engagement. Application developers call it time in app. Online publishers (like WIRED!) call it time on site. Wearable manufacturers are all about that time on wrist.

The software's gotten better, too, along with user experience. Collecting information is one thing. Presenting it in a way people find comprehensible, motivating, and actionable is another. Consider something as simple as a reminder to move—another feature ubiquitous among newer fitness watches. Buzzing people once an hour, regardless of their current activity, is annoying (if my device tells me to get up and move while I'm on a hike, it's going off a cliff). Instead, most wearables now tell you to move only if you've been sedentary for more than a predetermined period of time. And according to Fitbit, at least, those reminders work. "People who would get six reminders to move a day, on average, after a few months, they get about 40 percent fewer reminders to move," says Shelton Yuen, Fitbit's vice president of research. "That’s a very detailed example, but I feel like it’s such an important one, because it means the user's innate behavior is changing."

Of course, Fitbit would say that. But outside experts agree that fitness tech is improving. "There are two things, specifically, that apps and devices are actually getting better at," says University of Pennsylvania researcher Mitesh Patel, who studies whether and how wearable devices can facilitate improvements in health. The first is leveraging social networks to stoke competition or foster support. Researchers led by Penn State psychologist Liza Rovniak recently showed support networks to be highly effective at increasing physical activity in unmotivated adults, but Patel suspects the leaderboard format, a popular way of promoting competition by ranking users, fails to inspire anyone but those people at the top of the charts (who probably need the least encouragement anyway).

The second is goal setting. "We know that people need to strive for an achievable goal in order to change their behavior," Patel says, the operative word there being "achievable." The problem with early fitness trackers was that they all used the same goal (step count) and they all set the bar way too high (10,000 steps). But the average American takes just 5,000 steps a day. Asking her to double that figure isn't just unrealistic—it can actually be discouraging.

But today's fitness wearables tailor their feedback to users' individual habits. Rather than tell you to take 10,000 steps, Garmin's Insights feature will nudge you if it senses you're moving less than you usually do on a given day of the week. Fitbit now allows users to set and track personalized goals related to things like weight and cardiovascular fitness.

These are just some of the ways wearable manufacturers have begun borrowing theories from psychology and behavioral economics to motivate users in recent years—and there will be more to come. "They're constantly adding features," says Brandeis University psychologist Alycia Sullivan, a researcher at the Boston Roybal Center for Active Lifestyle Interventions and coauthor of a recent review of fitness tracker motivation strategies. Now that these devices are small, powerful, and packed with sensors, she says, expect most of those features to show up on the software side of things. "That's where these companies are most able to leverage the data they're accumulating toward interactive, personalized information you'll actually use."

It may have taken them a while to catch up with the Facebooks and Netflixes of the world, but our fitness devices are finally poised to hijack our brains—and bodies—for good.