Fitness trackers can inspire activity

• Bodymedia, $89-$119, www.bodymedia.com. Records steps, calories, distance and sleep. Judged the most accurate tracker of calories burned in a 2014 study.

• Fitbit, $59.95-$99.95, www.fitbit.com. Measures steps, distance, calories, sleep. Multiple models to choose from, can clip on a pocket or worn on the wrist. Wireless synching via computer or smartphone.

• Jawbone Up, $79.99-$129.99, www.jawbone.com. Simple, attractive design doesn’t look like a gadget. It tracks your steps, calories and sleep, and it can alert you when you’ve been inactive for predetermined period of time. Requires an up-to-date smartphone.

• Misfit Shine, $99.99, store.misfit.com. Looks like an elegant watch on the wrist; can also be worn as a clip or a pendant. Measures steps, calories distance and sleep.

• Withings Pulse Ox, $119.95, www.withings.com/us/withings-pulse.html. Display shows steps, altitude, blood oxygen levels, pulse and sleep; can be worn on the wrist or on a pocket or waistband. Downloads and tracks data via smartphone.

The innocuous little band on Seth Mnookin’s wrist may not seem like much, but it has transformed the way he goes about his day. The device, a fitness tracker called Fitbit, counts the steps he takes and allows him to log them online.

“It’s changed my behavior dramatically,” says Mnookin, a 42-year-old journalist and associate director of MIT’s science writing program. Mundane tasks such as walking to faculty meetings, returning books to the library and going out to feed the parking meter no longer feel like time-sucking chores, Mnookin says. Instead, they’re opportunities to accumulate more steps.

Tracking steps is nothing new: For years, public health experts have promoted pedometers as a tool to encourage people to become more active. Those old-style devices, which clip on the waistband and count steps, are cheap and simple, but they lack the bells and whistles found on such high-tech trackers as Fitbit, Jawbone Up, the Withings Pulse Ox and Misfit Shine, which synch your data to your smartphone or computer and allow you to keep detailed records, set goals and share and compare your data with friends. Most also calculate distance walked or calories burned and allow you to track other types of data, such as diet and sleep.

But do these extra features amp up your motivation or produce better fitness results? Not necessarily, says Catrine Tudor-Locke, director of the Walking Behavior Laboratory at Pennington Biomedical Research Center in Baton Rouge. “We find that a low-tech pedometer with a battery that lasts three years changes behavior just as much as any of these fancy devices that you have to charge more often and connect to download,” she says.

The most important thing that fitness trackers do is make people aware of how much (or how little) they’re moving, Tudor-Locke says, and that usually motivates them to find opportunities for physical activity.

Mnookin has found that his Fitbit feeds into what he calls his obsessive-compulsive side. With a busy job and two young children, he doesn’t have much time to spare, but his desire to end the day with a pleasing number of steps has spurred him to engineer physical activity into his daily life.

Mnookin aims for 10,000 steps per day — Fitbit’s default goal, which works out to approximately five miles of walking. It’s an amount of exercise he can’t usually reach without some deliberate effort, so he bikes to work most days and has made a habit of doing laps around his office building. For 19 straight months, Mnookin has never logged fewer than 10,000 steps. “I haven’t missed a single day, even if I have to walk around an airport or do laps around my kitchen table,” he says.

Research suggests that pedometers can help people improve their step counts. A review published in the Journal of the American Medical Association examined 26 studies involving more than 2,700 participants and found that “overall, pedometer users increased their physical activity by 26.9 percent over baseline.” The study also concluded that pedometer users significantly reduced their body mass index as well as their blood pressure. Setting a goal, such as Mnookin’s 10,000 steps per day, was a strong predictor of increased physical activity.