My life with the BodyMedia Fit activity tracker

If you really want to know how many calories that exercise burned, the BodyMedia Fit easily beats other popular trackers. But being an armband, rather than wristband, isn't particularly comfortable.

Danny Sullivan
Danny Sullivan is a journalist who has covered the search and internet marketing space for over 15 years. He's founding editor of Search Engine Land and Marketing Land, and writes a personal blog called Daggle (and maintains his disclosures page there).
Danny Sullivan
7 min read
BodyMedia Fit

Time to assess the last of the four activity trackers I've been living with for over two months, the BodyMedia Fit.

If you're serious about tracking every calorie burned as accurately as possible, this makes the other trackers look like toys. But it's also the least comfortable to wear, and monthly subscription fees may also put some off.

BodyMedia sells two versions of the Fit. The "Core" version for $120 lacks Bluetooth and so can't talk directly to apps on your iPhone or Android device. The "Link" version sells for $150 and does have Bluetooth connectivity. I've been using the Link version, which BodyMedia provided me with.

The Nike FuelBand thinks I burned 42 calories; the Jawbone Up registered 66, and the Fitbit Flex counted 85. That four-to-nine times less than the 372 the BodyMedia registered. And given the amount of sweat pouring off of me, I'm pretty sure the BodyMedia was the closest to getting it right.

The other trackers all acknowledge that they're not perfect, especially for activities where your body might be mostly stationary. Weight-lifting, bike riding, paddleboarding -- if your entire body isn't moving, then the accelerometers they depend on can't register your activity so well.

The BodyMedia device has an accelerometer and more, sensors that rest on your skin to measure sweat and skin temperature. This why it can be so much more precise about what you're doing.

Viewing the data
Your activity data flows into a nice online activity manager, where you can also do things like log food, see your sleep, and check on steps:

BodyMedia Activity Manager

One of the things I absolutely love about the interface is that you can select any time period, highlight it, and then get the amount of calories burned during that time. For example, here's the zoom-in on my spin session:

Zooming in on an activity

My other devices don't allow this type of granularity. Want to know how much you burned in an activity with the Jawbone Up? If you didn't set the timer, you're out of luck. Fitbit will give you estimates for every 15 minutes, but it's pretty inconvenient to add all those up -- and you better have remembered when your exercise started. Nike gives you an hour-by-hour summary, which is less useful and -- worse -- isn't in calories but instead in "NikeFuel."

There is an option to add "off-body" activities, if you weren't wearing your armband during a particular exercise. Both the Fitbit and the Up have a similar feature. But I never needed to use it, since I was constantly wearing the Fit, plus it seemed to be doing a great job of accurately tracking what I was burning. For the others, this feature is more needed as a way to catch them up to what they might miss.

Logging food, sleep and weight
As with the Fitbit and Jawbone Up, the BodyMedia Fit allows you to log what you've eaten. In my testing, I've found keeping track of the food I've consumed one of the very best ways to lose weight. I've also found it continues to be a pain, regardless of what device you use. But the Fit, like the others, does try to make it easier.

Logging food with the BodyMedia Fit

As you can see above, the Fit's Activity Manager remembers frequent foods that you've logged for particular meal times. You can also add custom foods or combine several foods into a recipe, for frequent use.

Also like the Fitbit and the Up, the Fit will track your sleep, logging how much it actually thinks you've slept versus your "lying down" time:

Sleep tracking with BodyMedia Fit

As I've written before, I find the sleep tracking more a novelty than an essential with these trackers, but if you want it, the Fit does have it. Better, you don't have to put it into sleep tracking mode, as you required with the Fitbit and the Up. The Fit just figures out when you're sleeping.

As for weight, if you have a Withings wireless scale, that can link to your Fit's Activity Manager and track your weight automatically. BodyMedia sent me the latest Withings Smart Body Analyzer to use with the Fit. It worked very well, as seamlessly as my Fitbit Aria scale sends to my Fitbit account.

Goals and motivation
The other trackers I've used all have various ways they try to encourage you to make progress by socially interacting or comparing with others. The Fit has none of that. You're not going to be sharing your stats with others, at least not with anything native to the device and its software, though a range of third-party apps may help, if that's what you're after.

As with the Jawbone Up, there's also no direct display you can look at to see if you're hitting a particular goal. I continue to love that type of feature with the Nike and Fitbit Flex trackers, where a button push or tap gives me an indication on the device itself if I need to do more work to hit my daily goal.

On the other hand, I really appreciated what felt like were sensible weight loss goals that the device's Activity Manager allows to be set. I've been wanting to lose about 10 to 15 pounds for ages. In a few steps, it outlined what I needed to cut my calories to and increase my burn to, in order to lose that weight:

Weight goals in BodyMedia Fit's Activity Tracker

I especially liked the options to extend over longer periods of time. I like to eat. So cutting back a little and losing only a half-pound per week may be more sensible and realistic for me. But it's also nice to understand how much longer it will take to reach my goal. Maybe I want more pain for a shorter period of time. If so, those options are also presented.

Comfort, the next version and unexpected surprises
One of the biggest drawbacks to the Fit is that it's not particularly comfortable. It's never painful to wear. Sometimes I would even forget I had it on. But usually, I was aware I was wearing it. Several times during the day, I'd move it slightly on my arm, to give a break to the particular place the sensors were touching. When I took it off, I knew it was off and felt a bit more relaxed.

Overall, I've figured that's the price you pay for the better accuracy that the Fit delivers. But even BodyMedia seems to know it could use something better. The "Core 2" is due out (PDF) later this year, likely in September, BodyMedia told me. It will be smaller than the Fit, waterproof, and have a more "jewelry-like" bands -- several, actually, to choose from:

BodyMedia Core 2 BodyMedia

I'll certainly be interested in the next version. As for the current one, aside from the comfort issue, the cloth band I used unexpectedly broke when I was slipping it off my arm one day. BodyMedia quickly sent me a replacement. If I'd purchased the Fit, I imagine it would have been covered under the warranty. New bands are $13, so it's not a huge expense, but it wasn't reassuring to have happen.

Broken band, small crack

More concerning was a small crack that appeared on the back of my sensor unit. It hasn't prevented it from working, but when I mentioned it to BodyMedia, I was asked if I used sunscreen. Yes, often. It turns out that sunscreen may have this effect on the device, so the company warns against having the Fit in contact with skin coated this way.

For me, once I knew, it was easy to avoid. The band is worn on my upper arm, which is usually covered by my shirt sleeve. I just stopped going so high in applying sunscreen to my arm. But a device that's more resistant to sunscreen would be nice.

Love the accuracy but not casual enough?
Overall, if I was seriously trying to lose a lot of weight or make major changes to improve my fitness, I can see why the BodyMedia Fit would be very useful. Or, if I really were trying to do the "quantified self" thing, the Fit is far more likely to actually quantify accurately the body data some want compared to other popular activity trackers I've tried.

But for me, I just want to lose a few pounds and be a little more active. I don't need precise metrics. I need that "nudge" to be more active that the Fitbit Flex or the Nike FuelBand seem to provide better.

The combination of having the BodyMedia Fit with other devices has been very nice, however. Being able to use the Fit as a reality check on the others has helped me better understand what they track and how I might manually log particular activities to improve what the Fitbit and the Up record, if I wanted to (Nike doesn't allow for manual logging).

Those looking for a middle ground with the Fit's accuracy and the comfort of the others might consider both. That's pricey. You're buying two devices. But you'd be getting the best of both worlds.

Alternatively, stay tuned. The Core 2 might turn out to be a more comfortable device, when it arrives. Plus, the purchase of BodyMedia by Jawbone in April may lead to a more accurate Up or similar device, in the future.