This device boasts a year-long charge (we never juiced it up once during four months of testing). When it is finally time for a replacement, the vivofit takes easy-to-find watch batteries.
Like most trackers, it counts steps, calories, and sleep, but it’s differentiating feature is the “move bar” on the display, which monitors sedentary time. Sit for longer than an hour, and the red bar flashes to remind you to get up. The device can store three weeks of data between syncs, and uploading data is a cinch using Bluetooth and Garmin’s Connect platform. It also pairs with Garmin’s ANT+ heart-rate monitors.
No backlight means the display is hard to read in low light. Warning: Be sure to set the sleep mode to avoid missing data overnight.
$130 ($170 with heart rate monitor); .9 oz.; garmin.com