PRODUCT REVIEW: So for the last week, the Insta-Daughter and I have been using the Fitbit Flex, a motion-sensing wristband that syncs with a smartphone app to track diet, activity, etc. My sister-in-law, who’s lost 24 pounds in a couple of months using one, was showing hers off at a family get together a while back and it seemed kind of interesting.

Tiny accelerometers in the wristband track all your movements, and it syncs via bluetooth with your smartphone (or a computer or tablet). One of the big things it does is press you to move around: It wants you to get at least 10,000 steps a day, and offers a variety of encouragement. It also tracks your diet and exercise — you can log a weight workout, for example — and allows you extra calories. You can program in a weight-loss goal and it will adjust your food intake, etc. to reflect it.

It’s easy to use, and kind of fun to play with. It also tracks your sleep at night based on how much you move, which is kind of cool. (Unsurprisingly, I found out that I sleep like a baby, but I have a friend who discovered a sleep disorder only when he roomed with a physician on a college-reunion trip, so I suppose it could be useful to many, and it encourages you to get enough sleep.)

My bottom line: If you’re already doing a serious training or exercise regime, a la Rippetoe or Crossfit, it doesn’t have much to offer beyond what (much) cheaper smartphone apps like Livestrong or MyFitnessPal already offer: If you’re doing 5 sets of squats at 250 pounds, you know it already. But if you are a couch potato seeking encouragement to be less couch-potatoey — and, let’s face it, that’s most Americans — then this just might do the trick. Otherwise, it’s just a toy. Though I like toys. . . .

The Insta-Daughter, whose exercise regimen runs more to Ballet Beautiful, Blogilates, and long walks than to Rippetoe, likes it a lot more than I do. (She calls it the equivalent of a “What Would Jesus Do” wristband for diet and fitness). She’s been working to increase her steps/day, going over 15,000. That’s a lot of steps, and if you do that, you’ll be in a lot better shape than if you just sit on the couch. Consider it a tool to help you pluck the how-hanging fitness fruit. And that’s not such a bad thing.