Editorial note: The Fitbit One has been discontinued. You can still find the model on some reselling sites, but we'd recommend looking through our list of the best Fitbits or best fitness trackers if you're looking for a new wearable.
The One is a fitness tracker from Fitbit, a company known for its wearable devices. At $99.95, the One is in the mid-level price range for fitness trackers, more expensive than the Fitbit Zip ($59.95), but cheaper than the Nike FuelBand ($149), and the same price as the Withings Pulse. The One tracks all the basic metrics, including sleep, steps taken, distance walked and calories burned, and also tracks the number of floors you climb. I tested the One for a week, and here's what I found:
Overall Rating: 6.4/10
Pros: The pros of the One include its small size, the way it lets you connect with friends, the alarm that you can set, the inclusion of a wireless dongle to synch with your computer, and a lower price than some other fitness trackers.
Cons: The cons of the One include a sleep graph that's somewhat difficult to navigate, the tendency of the device to count "steps" while you're asleep and the lack of certain features found in higher-priced fitness trackers, such as the ability to track cycling.
The Fitbit One is a small, lightweight tracker, which makes it easy to wear the device and forget you have it on. The One is small enough to fit into your pocket, or you can place it in the provided clip and wear it on your belt/waistband as you would a pedometer. If you're like me and prefer "pedometer-style" trackers to ones you have to wear on your wrist all the time (as you have to do with the Jawbone UP and Nike FuelBand), the One may make a good choice you.
To track your sleep, you place the One into the provided sleep wristband. Although the band is quite large, it is comfortable, and I didn't notice it while I slept. The band is made of soft cloth and easily wraps around your wrist. A strip of Velcro on the band means it can fit any sized wrist. If you set an alarm (which you can do through the Fitbit mobile app), the device quietly vibrates to wake you up in the morning.
The device and accompanying mobile and Web app are very user friendly. You push a single button on the device itself to cycle through a display of your steps taken, floors climbed, distance walked and calories burned, as well as the time of day. You'll also see an image of a flower that grows the more active you are, so you can monitor your progress at a glance.
You can view more-detailed information about your activity with the Fitbit app, or online through your Fitbit account. The device syncs wirelessly with your mobile phone through Bluetooth, or with your computer through the provided wireless dongle (a small piece of hardware you plug into a USB port to allow the device to sync). Fitbit is one of the few trackers that provides a wireless dongle, which may be especially useful for people who do not have a smartphone.
In your Fitbit account, you'll see all of your data nicely laid out on the dashboard, with a square for each metric (such as steps, calories, etc.). Clicking on each square will show you more information about that metric, such as how many steps you took on each day of that week. The account also has a "log" feature, which keeps a record of your activity and can show you your data from any specific day in the past. You can also enter a record of the food you eat through the app or through your account.
The One's app displays your sleep data as a graph, with red lines indicating when you woke up and turquois lines indicating when you were "restless," or moving during your sleep. However, if you toss and turn a lot, the graph ends up with many red and turquois lines, which I found difficult to decipher. For example, one night I was "restless" 24 times, so the app showed 24 turquois lines. Clicking on each of these tiny lines will tell you when you were awake or restless, but this is difficult because the graph is quite small.
Value of Information: 6/10
Fitbit has default "goals" so you don't have to set them yourself if you're not sure what your goal should be. The default goals are: 10,000 steps a day, 5 miles a day, 30 "active" minutes and 10 floors climbed. However, I could not find an explanation for why Fitbit picked these goals in particular — is this how active you need to be to be healthy? The app didn't make that clear. (In contrast, the Withings Pulse sets a goal of 150 minutes of walking or other activity a week, which the Centers for Disease Control and Prevention recommend as a minimum for exercise).
The One also calculates your "sleep efficiency," an indicator of how well you slept, but does not provide advice for what you need to do to rest better. Sleep researchers also say that fitness trackers tend to overestimate how long you sleep, because the devices are more likely to register that you are asleep when you're actually awake.
I also noticed that the One kept tracking my steps in sleep mode. I woke up one morning to see I had taken 25 steps at night. No, I wasn't sleepwalking; the device must have registered my movement (tossing and turning) as steps. But why track steps when the device is in sleep mode? These 25 steps added to my total for the day, but they were not actual steps.
In addition, the device can't track swimming or biking activities, so people who frequently engage in this kind of exercise may want to look for another tracker. However, you can keep your own record of biking, swimming or other activities in the log section of your Fitbit account.
The Fitbit One includes a number of features that motivate you to be more active.
Fibit encourages you to connect with friends who also have Fitbit accounts. In the app or your account, you can see how your progress compares to that of your friends. If you have a competitive streak, seeing how you rank among your friends may give you the motivation you need to get in that extra daily walk.
You'll also earn "badges" that appear on your account when you reach fitness milestones, such as a badge for reaching 50 "lifetime" miles, or a badge for walking more steps in a day than you ever have (my best was 15,000 steps), which provides incentives to keep using the device.
And the fitness tracker itself flashes encouraging messages on the screen, such as "You Rock!" and "I'm Ready!"
Editor’s Note: In February 2015, we changed the rating system we use in our fitness tracker reviews from a 5-star system to a 10-point system. Not all of our ratings were a straight conversion (i.e. 2/5 stars = 4/10 points). Instead, we adjusted some of them in order to give our readers a better idea of how these devices perform in relation to each other.
More Reviews: See all our Fitness Tracker Reviews to find the best one for your needs.
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Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.