Fitbit Flex: Review

The Device

When I opened up the Fitbit Flex, the tracker was already inside a wristband (it comes with two wristbands – a large and a small). I was mildly disappointed to find I’d need to charge it before being able to use it, but was glad I’d be able to see the device sans-wristband, and see how the charger works. The image below is from What’s neat is to compare the tracker’s size to the USB plugs in the picture (the device to it’s left is a tiny USB dongle for syncing wirelessly to your PC – it’s included, but so far, I haven’t used it – I’ll get to that). The tracker is extremely light – lighter than the wristband it’s worn in. I’m very impressed that the bluetooth, battery, memory (up to a week’s steps) and tracking sensors all fit into such a tiny, light package.

Fitbit Flex

To charge the tracker, you can just pop it out of the wristband, and click it into the charger. It charged up pretty quickly on a 2A USB charger, but would easily charge on a standard 1A overnight. The wristband’s opening on the inside has lips of slightly thinner rubber to make it flexible enough to stretch around the tracker while you’re inserting it, but sturdy enough to keep the lightweight tracker securely held, once inside. The edge between the hard plastic “display” (which is really just a window for the 5 tiny LEDs on the tracker) and the rubber part of the wristband seems a bit cheap, like it’s likely to be the first point of failure, but after about 2 weeks of usage, mine isn’t showing any signs of separation.

Wearing The Wristband

The wristband is made of a not-really-stretchy rubber, similar in texture to kids’ rubber watch bands, but is smoother, and less “sticky” against the skin. It’s slightly wider than a livestrong-style wristband, and feels about the same to wear. It’s doesn’t take long to get used to wearing, and doesn’t get in the way. I found that when typing on my Macbook’s keyboard, the tracker scratched against the metal of the laptop quite a lot – not enough to make marks, but enough to be a bit annoying. On my desk keyboard at work, however, it doesn’t get in the way at all, since my wrists are slightly elevated while typing. The tracker is water resistant, and they advertise that it’s fine to wear in the shower or out in the rain. So far it’s been no problem at all to get a bit sweaty, or wet in the shower. I’d say that the water resistance comes in two parts – the completely sealed tracker, and the rubber wristband – so I’m pretty confident in it’s safety, but I still wouldn’t submerge it (doing dishes, or swimming, for example).

…When sleeping

Wearing the wristband while sleeping has been a different story. The tracker is supposed to measure how often you’re restless or even wake up while sleeping, and graph it. For the most part, I’ve found this info pretty useless – I usually know how well or poorly I sleep, and how long. On top of this, the Fitbit’s sleep stats are pretty weak when compared to an app like Sleep Cycle (which uses your iPhone placed on your bed to detect motion). The only advantage I see of Fitbit over Sleep Cycle is the ability to distinguish my motion from my wife’s, since the Fitbit is on my wrist, instead of on the bed. Compare the apps below. Combine all of this with the fact that the wristband feels big and obtrusive at night, and I don’t wear it. I take it off at night, mostly because I frequently sleep with my hands under my pillows, and while the bottom of the wristband is super slim, the top is big enough to make it annoying to slide my hand under my pillow. I think this is purely a personal preference, though – and would definitely be different for everyone.

![sleep cycle app](/content/images/2014/May/sleepcycle.png)
![Fitbit sleep tracking](/content/images/2014/May/fitbit_app.png)

Activity Tracking

For the most part, I really like the Flex’s activity tracking. It does a good job measuring my steps, comparing it to my activity level and step tracking with a standard pedometer kept in my pocket. Sometimes, it doesn’t do quite as well, but I think this is expected. I did some mountain climbing last weekend for about 3 hours, and it only logged about 15 minutes of “active” time and less than 4000 steps – a low measurement for ~1.5 miles walked each way, plus the time climbing and hiking up the top of the mountain. For pretty normal walking, it’s pretty accurate, however. I really, really like the vibration. I almost didn’t get the Flex, since I was trying to hold out for a smart watch, but most of the smart watches out right now are missing a few key features, tight smartphone integration, or are on a long backorder. I love the idea of getting a silent wrist notification, and getting some info just by glancing at the back of my wrist. The flex does that in a tiny way. Tap it twice to get a milestone for your steps so-far that day (each LED is 20% of your goal, which defaults to 10k steps). When you hit each milestone it lights up to show the new “dot” and when you hit your goal, it even gives you a tiny vibration in addition to the light. The notifications are tiny enough to be unobtrusive, but big enough to get your attention if you’re not very distracted (I have missed both the lights and vibration when walking/talking).

Should You Get One?

Don’t have an activity tracker or smart watch? Then sure – it’s only $100, and if it helps you get off the couch and get moving, that’s money well spent. If you’re like me, and never do well with remembering to put a pedometer in your pocket each morning, or just don’t want to have something in your pocket all day, the cost is worth it to have an unobtrusive, wearable tracker instead. Have a smart watch, or don’t mind carrying your phone or another tracker with you all the time? Maybe not. This is definitely not a necessity, but it’s helpful. Some people do really well tracking things like activity, diet, carbs, calories, sleep – anything. Some people do well only tracking some of it. Some people do well just winging it and adjusting based on intuition or body response. Just figure out which one you are, and try to bit active and healthy.