I don’t like being encumbered. That’s why I stopped wearing a wristwatch years ago, around the time I got my first mobile phone. That’s also why I’ve long looked askance at activity-tracking bracelets like the Fitbit Flex, the Nike FuelBand, and the Jawbone UP. I liked the idea of having more data about my exercise routine, but I just didn’t want a bulky, awkward gadget flopping around on my wrist all day.
But lately I’ve been trying out a sleek new entrant in the fitness wars: the Shine activity tracker from Misfit Wearables. It’s a thin metal disc about the size of two U.S. quarters, and it slips inside a wristband, a pocket clasp, or an amulet on a necklace. It’s the first fitness tracker that’s so small and inconspicuous that I was able to imagine wearing it full-time, which is what I’ve been doing for the last two weeks.
The company is hoping a lot of other people will see Shine the same way. Misfit co-founder and CEO Sonny Vu says his team’s top goal was making a device that was simpler and more wearable than other activity trackers on the market. He sees the slim design, together with the fact that the Shine doesn’t require external cables or regular recharging, as Misfit’s main advantages over its larger rivals. “The option to wear it anywhere” is “a big deal” for Misfit’s customers, especially women, Vu says.
And those are real pluses. But the more I use the Shine, the more I wonder whether any of today’s wearable fitness trackers—which are all built around the same type of internal sensor, a three-axis accelerometer—can really live up to their creators’ promise, which is to make you a more active person.
The basic problem is that there’s only so much data you can gather using an accelerometer. No matter how fancy the mobile app that goes along with the tracker, it’s really just counting the number of footsteps you take every day, the same way an old-fashioned mechanical pedometer would. And unfortunately, the number of steps you’ve walked is a pretty blunt measure of your actual energy expenditure or fitness progress.
Maybe you’re the type of person who doesn’t really care about the data. Maybe all you need to motivate you to get you off the couch and spend more time walking or running today than you did yesterday is a little feedback from some flashing lights on your wrist. In that case, the current generation of wearable trackers may work well for you.
But if you’re like me and you want more fine-grained information about your workouts—such as where you ran, exactly how far you went, how many calories you used, and whether you’re getting faster—you’ll still need to carry a smartphone running some kind of fitness-tracking app like RunKeeper or RunMeter. And that makes Shine and other activity trackers a little redundant.
When it comes to exercise monitoring, in other words, less is less. The Shine, which sells for $120, is certainly elegant—and it makes a cool wristwatch, separate from its activity-tracking features. But a tiny device can only collect and display tiny amounts of information.
Let’s back up a bit and talk about the thinking behind the Shine’s features. As Elise Craig reported in an Xconomy news story about Misfit last year, Vu and his co-founder Sridhar Iyengar come from the world of medical devices. Their previous company, AgaMatrix, built an iPhone accessory that diabetics can use to measure their blood glucose levels. It’s marketed by Sanofi under the name iBGStar, and Vu thinks it’s successful because it’s small and easy to carry around; it doesn’t need much of an interface, since it connects to another device that users already have with them.
The Shine fits the same mold. (Vu and Iyengar recruited former Apple CEO John Sculley as a third co-founder to start Misfit in late 2011. They’ve raised backing from Founders Fund and Khosla Ventures, as well as donors at Indiegogo, who gave $846,000 in a crowdfunding campaign that ended this January.) The aircraft-grade aluminum disk is just 27.5 millimeters in diameter and 3.3 millimeters thick, and weighs 10 grams. The outward face is ringed by 12 LED lights, which shine through tiny laser-drilled holes that are so narrow that water can’t get through, meaning it’s safe to swim or shower while wearing the Shine.
Inside the device, there’s an accelerometer, a processor, a memory chip, and a Bluetooth radio, all powered by a standard watch battery. As you go through your day, the accelerometer measures changes in your direction of movement, and software algorithms translate that data into points measuring progress toward your personalized daily activity goal.
When you tap the device twice with your finger, the LEDs light up to show how close you’re getting to your goal. If you’re at 500 points out of 1000, for example, you’ll see six lights. The LEDs also show the current time, plus or minus a couple of minutes, using a clever sequence of lights that mimics a clock face.
When you want to review your activity, you call up the Misfit app on your iPhone, place the Shine on the screen, and tap it to begin a wireless sync session. The part about putting the Shine directly on top of the screen isn’t just a gimmick: to save battery power, the Bluetooth radio emits an extremely weak signal, so it needs to be right next to the phone to connect.
Once you’ve synced, the Misfit app shows you exactly how many points you earned each day and how many steps you walked or ran. Using some rough algorithms based on your height and weight, it can also
