Fitbit Ultra Review

Pervasive monitoring is one of the visions of my future. When our technology is able to unobtrusively and transparently keep track of us. Where we’ve been, how many calories we burn, what we see, what we do, where we are, the state of our health. Then, be able to distill this information and provide feedback. Privacy concerns aside, I think the information is meaningful and can be applied in interesting ways.

I had this in mind when I ordered a Fitbit. My geeky self looked forward to adding yet another toy to my utility belt.


What this is $100 device? A sensitive accelerometer that measures movement all the time. It beams this information to the mothership in the cloud, which populates their website where you can track this sort of interesting stuff. The logic can derive what you’re doing – walking, running, sleeping, climbing. It measures how active you are and can calcuate the approximate number of calories you’ve burned.

Design and Ease of Use

The Fitbit a couple of inches long and U-shaped to clip to a belt or other bit of clothing. It’s covered with a transclucent rubbery coating that hides a screen, which lights up when you push the single button on it. Some people have complained about breaking it at the clip. I can see this happening – the unit appears to be made entirely of plastic. I can attest from personal experience that belt-mounted items tend to lead hard lives – espeically the clip parts. The Fitibt comes with a holster with another, fatter clip for attachment to thicker items. I think I will be using that most of the time, or dropping it into my pocket. Also included in the package is a soft wristband to hold the Fitbit during sleep. More on that later.

The physical interface features Apple-like simplicity. It logs all the time, no mater what. There is a USB-powered dock that charges the device and also contains the wireless receiver. The Fitbit can be inserted into the dock either forwards or backwards – either orientation works; a clever touch. The battery lasts 3-5 days. So long as the dock is plugged into a computer with the Fitbit software running, the Fitbit continuously syncs with the mothership when it’s within range of the dock – about 15 feet. As with the rest of the core functions, the sync is totally transparent to the user.

Tapping the button on the unit cycles through the different metrics – steps, floors climbed, calories, distance travelled, time. Holding the button starts and stops activity logging, which lets you designate specific periods of activity you want to track. You don’t actually input the type of activity – the device (or website logic) figures it out for you. Except for sleep, you don’t really need to identify activities manually – you can always go to the website and isolate activities you want, by time of day. The metrics reset daily.

It’s attractive and well-designed in both appearance and functionality. I don’t give such accolades lightly.

Website, Metrics

The website is the primary interface for the Fitbit. There you input your details, height, weight, gender, etc. – the data needed to estimate activity based on the accelerometer motion. You can also tweak the device settings, such as sleep senstivity and whether the screen is oriented for right or left handed use.

The dashboard on the website summaries your daily metrics and activity and you can log other things like food, weight, blood pressure and glucose. It integrates with other fitness tech toys like the Withings scale. It can also feed other social networking and health-related websites such as FourSquare,, Lose It and Microsoft Health Vault.

As is the norm for any modern social media site, the Fitbit website awards motivation badges for various levels of accomoplishment – daily steps taken, floors climbed, total mileage, etc.

Collectively, it gives you a picture of how active and healthy you are.

Sleep Measurement

Aside from motion measurements, the Fitbit measures sleep. To do this, you wear the wristband, housing the Fitbit, on your non-dominant arm. It derives your quality of sleep based on how often you move as you sleep and how quickly you fall asleep. Apart from logging each time I go to the bathrrom, I’m not really sure how accurate it is. It seems to be accurate in measures how quickly I fall alseep (within minutes), although it logs anywhere from 6-12 one-minute periods where I’m awake, but I have no memory of it. Presumably, I’m in a light sleep, moving around, but not entirely awake.

Motion Accuracy

I tested the Fitibt in a variety of activities and compared it to the Garmin Forerunner 405cx GPS, the electronic pedometer on my Sony mp3 player and actual cartographic distances measured using Google Maps.


For walking, the steps counted was very accurate when measured against the mp3 player. To calculate distance, you input your stride length and it multiplies that by the number of steps. As far as I can tell, it doesn’t directly measure later accleration like the Nike+ footpod. There’s also no way to calibrate it over a known distance. Therefore, the accuracy is entirely dependent on the accuracy of your input for your walking stride and how consistent your stride actually is. I measured my walk to work many times, and it was accurate to within 100m over the 1.5km route.


For hiking, the Fitbit counts steps as accurately as walking. Due to the uneven terraing generally encountered while hiking, there will be more variation in stride length, vs. street walking. In a hike of 16.2km, it measured 15.75km. That’s not bad.


The Fitbit appears to severely undercount steps while running. The distances it reports are about 60% of the actual run. The number of strides it measures is low. I can tell because it’s reporting a stride ride of 120-140 steps per minute. I know my stride rate is 183 steps per minute, measured using high-speed video using the Asics Foot ID system. I was quite disappointed it was so inaccurate for runs. I used it on many runs, mounted both on my arm and waist, all with the same results.

Inline Skating

It is wildly inaccurate for skating, although I expected that, since it’s not a step-related activity. It looks like it might measure strides correctly, but since there is so much glide during skating, the distances measures are totally inaccurate. The skating motion seems to trigger the climbing metric, as it reports a crazy number of stairs climbed.

In a Nutshell

The Fitbit is ideal for people who are moderately active and using walk-paced activity as a means of fitness. The website can motivate users to maintain and improve their activity level.The primary advantage is it monitors all the time, so long as you remember to wear it, and automatically uploads info to the mothership.

The sleep measurements are very interesting, although the website doesn’t really suggest any corrective action to improve the quality of sleep.

The inaccuracy makes it useless for runners, which is disappointing. Running is something this type of accelerometer-based technology should measure well.

It’s useless for other non-step sports, such as cycling, skating and weight lifting.


  • Very nicely designed and easy to use.
  • Tiny and unobtrusive.
  • Transparent and pervasive monitoring and works automatically.
  • Good website and cross-integration with other sites.
  • Very accurate for walk-paced activities.
  • Interesting sleep measurement function.


  • Totally inaccurate for running.
  • Does not measure non-step exercise.
  • Does not self-calibrate for stride length.
  • It’s tiny and unobtrusive. It’s a matter of when, not if, this thing goes into the wash cycle.

The Future

I want a wrist-mounted unit that combines:

  • The accelerometer and ease of use of the Fitbit.
  • GPS for more accurate position and distance mesurement, like Garmin Forerunner.
  • Self-calibration to avoid stride length input, like Nike+.
  • Vibration alerts and bluetooth integration with my phone, like Jawbone Up.
  • Skin-based heart rate monitoring, like Mio, but more accurate and hands-free.
  • Non-invasicve glucose measurement (this tech doesn’t exist, as far as I know).
  • Weight measurement (I have no idea how this would work).
  • Records everything and beam it to the mothership transparently, via celluar data connection.
  • Emails me with instructions and feedback on what to do better, and when.
  • Tells the time and plays mp3’s (what the heck?).

Much of this tech exists – it’s a matter of mashing them up in a sufficently small and light package to be unobtrusive and with enough battery life to be not-annoying. I can’t wait for the future.


7 thoughts on “Fitbit Ultra Review

  1. Running Steps- This specific stride length can also be entered, in Your Account area of the FitBit website, thus overriding the default based solely on height & sex.

    Other Activities – The FitBit device itself is step-focused. The companion website includes a logging area, where one can enter the specific stats associated with any non-step activity. That having been said, many of us prefer to add non-step exercise and food tracking via, which transparently shoots its data to MFP also has a stellar iPad app, complete with barcode scanning re food intake.

    Weight – This can be entered manually at the site. Or, if, like me, you have the Withings Body Scale, the info will be pulled into FitBit (RunKeeper, MyFitnessPal and others) via website integration apps (read: just link the two).

    WebSite – Unfortunately, the FitBit website is stuck in the last century. Over-reliance upon Flash renders it iPad hostile. It’s LeaderBoards, used to compare stats with others, frequently inexplicably lags a few days. But, standing alone, the website does offer helpful individual progress info, which is the name of the game. Incidentally, privacy is king at you can be as private/public as personally desired.

    Accuracy – While walking / jogging / running, hills climbed are translated to “flights of stairs” climbed, a uniquely nice touch. Steps are as accurate as the separate walking and running stride lengths tied to your account. This conclusion follows personal tracking over a 10-day period, comparing with Garmin 310xt and calibrated Garmin food pod. (The 310xt replaces my old 305; one reason: the 310xt calculates calorie burn by heart rate, the 305 does not.)

    Bottom-line: Pre FitBit, my resting HR was an abysmal 83. Two months in, post FitBit, it has dropped to a consistent 52. As a 58 year old woman, I consider the FitBit a wise investment in my overall health, simply b/c the small device always keeps me informed of my activity level. As a stone cold geek, I rely on my Garmin 310xt & HRM to track accurate (HR-based) calorie burn; and, iPhone app iSmoothRun (with Wahoo key) to verbally tell me the second I switch to another HR zone. It would be wonderful to have one device that does all, but until then, I exploit the heck out of what “is” currently, and my health has improved dramatically as a direct result. I know me — no way in the world would I be walking, on average, 4+ miles and 10k+ steps *daily* otherwise, especially since I’ve worked out of my home office for years, while also being 24/7 caregiver to my darlin’ 89 yr old mother (Alzheimer’s). The daily fitness walking/running routine is also fantastic for conquering stress. Securing & maintaining good health is not a game, but, it can be fun! (Well, at least, for the geeks among us.)

    • Bnax, thanks for your detailed response. it’s so great to hear that you have seen so much fitness gain! Technology certainly makes is fun and easier to track. Do you find the fitbit matches the Garmin footpod? Since I wrote the review, I’ve input my actual runnning stride length, but the fitbit still seems to short-count my running steps (120-150/min, rather than 180/min). It’s using the right stride length, but using fewer steps, and therefore the calculated distance is short.

      I use a Garmin 405cx to track workouts. It also has HR-based calorie burn calculations, but admittely, I don’t wear the HR except for hill and interval training. I also have the Withings scale. I’ve tried a few of the iPhone apps, but my phone will likely suffer from water/snow/shock/dirt induced premature death.

      Currently, my health / fitness info sits in two ecosystems:

      Garmin Connect – DailyMile (it’s Facebook for athletes)
      Fitbit – Withings – LoseIt (for meal tracking)

      I’m waiting for the day when this can all tie together. I’m curious about the MotoACTV, but the waterproofing issue is a showstopper for me.

      • Yeah, I looked at the MOTOactv too. Quickly left that Amazon page when I caught myself *studying* the user comments. “Danger, Will Robinson” zone. 🙂 I’ll admit to also keeping a close eye on the upcoming Nike FuelBand. So far, just curious. (ugh, precisely how I wound up with a FitBit.)

        Yes, after calibrating the Garmin foot pod, I’ve been pleasantly surprised, consistently, to see the distance match among the FitBit, 310xt and iSmoothRun. Cal burn is all over the map tho, so I rely exclusively on the 310xt for that.

        If you check out the Twitter timeline for @FitBitNation (new, so only a couple dozen tweets thus far), you’ll see 2 links for stride calculators. One is walled in, within the FitBit forums. I tried them, then just did some math using only the Garmin. Pretty close matches. The one thing I can’t seem to get together is steps on the treadmill. Tready itself would have me well on my way to the moon, just to crack one solid mile, so I ignore that aspect. After tinkering with the FitBit stride length, I’ve finally got iSmoothRun, FitBit and the 310xt on the same page. BTW, you’ll also see a link In that twitter stream for Fitocracy, yielding an immediate invite if interested. Haven’t really checked that out, yet.

        It bears repeating: for *me*, the FitBit has been fantastic. Something about that blippity-blip flower, and it’s growing or missing petals keeps me faithful to my fitness scheme. At this point, I really wouldn’t want to be without any of these 3 core elements (320xt, FitBit, iSmoothRun). Lawd help me, I just ordered a Wahoo cadence sensor or my (comfort) bike. I’m thinking between walking outside, Tready and cycling, I’ll prevent boredom – the death of my prior “gonna get it togetha!” missions.

        Oh, I allow the 310xt to auto-upload to Garmin Connect, but actually use Mac’s RubiTrack on a day-in-day-out basis. ISmoothRun shoots the stats to RunKeeper as soon as I tap the Done button. RK then helpfully sends me an immediate atta-girl type email, informing me when I’ve reached a personal best. I did try DailyMile, before RK. RK won my heart by working with so many apps. Unfortunately, recent upgrades have killed its former GPS accuracy. Hence, the switch to the iSmoothRun app, although still feeding/using the RK site.

        BTW, please tell me I’m not the only one adding a few core stats to a special fitness-only gCal! Hey, the threat of seeing a completely empty block, like FitBit, keeps this gal honest.

        – MyFitnessPal (abandoned LoseIt, per MFP’s iPad app *and* 1-tap “see all nutrients” for the day)
        – RunKeeper, pulling/pushing data to assorted places
        …… FitBit
        …… Withings scale
        …… iSmoothRun
        …… Wahoo Fitness app (1-tap pull of 310xt data, then pushes to RK- easiest way to compare iSR data (Wahoo/iPhone) with 310xt data — remarkably close, usually
        – RubiTrack, cuz I believe in backing up stuff to my desktop, just in case one of the clouds gets a headache
        – gCal, as explained above

  2. I’ve got three separate gCal for fitness – running, inline skating and hiking! Although I use it for scheduling and sharing with groups, rather than logging stats. I use a local .xls for logging stats for equipment use and annual planning. I’m one of those gear geeks that has multiple pairs of running shoes and skates on the go at once.

    It looks like RK can import from Garmin, so I’ll give that another try. I’ve signed up for MFP and Fitocracy and wll give those a go too. There’s a FB group call TrainingMobs that looks to be similalr ot Fitocracy.

    I should have a bi-monthly review of fitness apps since everything changes and improves so quickly.

    Do you read DC Rainmaker? His blog is _the place_ for fitness tech.

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