FitBit Technical Review

Monday, October 12, 2009

So I've been using my FitBit for a week. Do I love it? Unequivocally! How accurate is it? Pretty darn accurate, but with only a week of data, it's hard to tell.

This post is the nitty-gritty about what it is, what it does, and how it does it. My next post will be my FitBit User Review, wherein I will tell you how it's affected my lifestyle this week, and whether it's been worth it to me.


Image from FitBit Flickr stream: http://www.flickr.com/photos/f

A FitBit is a little device that, with the free website, crunches data about your daily movement. The tracker saves your daily steps, mileage, calories burned based on that data, and also tells you how active you've been recently on a scale of 1 to 10. You can also put it into an annotation mode that currently tracks your movement while you sleep. Once you put in your age, gender, height and weight on your free website profile, the tracker data (which is uploaded wirelessly & silently every 15 minutes when you're within 15 feet of the recharging station) is then filtered into an array of bar graphs, pie charts and widgets that will tell you whether you're fairly active or mostly sedentary, how many times you wake up in your sleep and therefore how efficiently you sleep, what parts of the day you're most active during, and how many calories you burn on average every day. You can take it one step further by tracking your calorie intake, logging your weight, and making the calorie burn count more accurate by inputting exercises that the tracker may not track accurately, like weight lifting.


The FitBit ships with the tracker, a USB charging antennae, a holster for clipping it to thicker fabrics like a leather belt, and a wrist band to wear it in while tracking your sleep.

Image from http://www.fitbit.com/product

The tracker is pretty cool. It's smaller than most USB flash drives and has one button and a blue OLED display that's bright enough to see in anything dimmer than direct sunlight. Also, you can't seem to see it at all through sunglasses. I didn't have much of a problem checking it while hiking today, though. It's black with a nonslip texture, and the interior is a shiny silver plastic. The four displays available are steps, mileage, calories burned, and your recent activity scale. Hit the button once, and it shows the last screen you were on; hit it multiple times and it scrolls through them all. Expect a battery level indicator to be added in the future, as well; currently, the battery level only shows when you place it on the recharger, or hit the button while it's recharging. The battery needs to be charged about every five days.

The steps are surprisingly accurate, and because it works by sensing your movement, you don't need to input your stride length in order to get an accurate step count. However, "steps" is a relative term; you can also rack up steps by doing other movements, so if your step count seems high, this explains it. This seems pretty standard, however, as you can easily Google "step equivalents" for common exercises -- a by-product of the 10,000 steps a day recommendation by most health groups.

Mileage is calculated based on steps, and the default is surprisingly accurate as well. Stride length is calculated by your height and gender, I believe. However, if your mileage seems to be off, you can input your individual stride length in your website profile. The default worked fine tested against mileage signs on a hike I did today.

Calories burned is calculated based on steps plus your basal metabolic rate (BMR), which is the number of calories you burn by living, with your heart beating and your lungs breathing. Your BMR is calculated by standard equations based on the stats you input into your profile.

Your recent activity level is a seriously cute avatar of a flower. If you've been sedentary for the past few hours, it's a tiny flower; after about 45 minutes of cardio activity such as running, hiking or using an elliptical machine, it hits its maximum height of 10 leaves with the flower on top. You can have between one and ten leaves on your flower. It starts to shrink as you reduce your activity. The flower does not measure your daily total of activity; it measures your recent activity. The goal, then, is to keep that flower healthy by staying active throughout the day.

Stunting my flower's growth by working a desk job ;)

My flower after doing circuit training at the gym

To put it into "annotation" mode to track your sleep, you hold the button down until it says START. When you wake up, hold the button down until it says STOP. It does not say SLEEP or WAKE because annotation mode will eventually be upgraded to allow you to set start/stop times for activities, which I assume you can then assign to various activities using the website.

The tracker can be worn anywhere on your torso. My favorite is the fifth pocket in my jeans, with the shoulder as a runner-up for days I do circuit training. You wear it on your non-dominant wrist for sleep tracking purposes, either insert into the included wristband or attached to whatever else you prefer. At least one user prefers to clip it onto a Livestrong bracelet instead.

The wrist band is technical fabric with a soft velcro closure and a slit for your FitBit. I don't recommend clipping the FitBit into the opening. Just slide the whole thing in there. That way it won't fall out. The wrist band is really comfortable, but it might be a little bit loose on folks with very small, delicate wrists.

The recharging station is USB powered and has a fairly small footprint, about 3x3 inches.You recharge FitBit by clipping it onto the antennae. There is a reset button on the bottom. If you have a problem with your FitBit, you can force reset it by docking it and then holding down the reset button on the bottom with a pen tip or paperclip. The screen will flash with your current firmware version and the battery level. I've reset my FitBit once. I was a bit overzealous when I first unpacked it, and I think I hit too many buttons at once while docking and undocking it, and it froze, lol. I haven't had the problem since, however. And no, resetting it doesn't erase any of the tracker data.

Since attempting to clip the tracker onto especially thick fabrics could damage the FitBit, it comes with a plastic holster that works on things like belts and still leaves you access to the button and display. Users have reported that the holster falls off easily, so you might want to skip the holster and stick the FitBit in your pocket. Users have reported that it tracks just fine from your pocket.

The FitBit doesn't ship with software, but you will have to visit fitbit.com/start to download and install the FitBit Service Manager for Windows or Mac OSX. I'm unsure about whether anyone has it running on Linux yet.


The website is free. In fact, you can sign up now and track your eating and exercise habits without a FitBit. And let me tell you, it is smokin' fast, and the AJAXified interface is intuitive and user-friendly.

One of the first things you wonder when you log in is, "How the heck are they calculating my energy expenditure? There is NO WAY I burn that many calories a day!" Here's the answer from the FitBit staff:

If you don't have a FitBit, it estimates your daily calorie burn by calculating your expected energy requirements (EER) based on published formulas from the FDA and department of health. If you log activities, such as running or weight lifting, the website will add those calories to your BMR (remember, that's the number of calories you'd burn if you were in a coma). If the EER is higher, the website uses that data; if the BMR + activities total is higher, it uses that instead. If you manually log steps from a pedometer, they are added as a walking activity at 2.5 mph.

If you have a FitBit, it uses FitBit data instead. If FitBit data is unavailable (say you're checking the website from your office, and it's been 4 hours since your FitBit last wirelessly synced the data with the website), it will use your BMR. However, if your burn is less that 20% greater than your BMR, it will switch to either the EER formula or BMR + activites formula, whichever is greater. Now, say you go for a run while wearing your FitBit then log the run on the website. What happens then? Well, first of all, you have to include the start time of the exercise. Then, the website will select the calories burned by comparing your input activity against the FitBit data and selecting the higher calorie burn.

So yes, you really DO burn that many calories a day. If it doesn't make sense, then think about all the junk food you've eaten in the past week and then wonder why you're not a bajillion pounds.

Now, on to the rest of the website. :)

You have a dashboard, a tracker, and a community tab.


The dashboard includes a ticker showing your progress on your primary weekly goal, which can currently be set to steps and mileage, but more options will be added later. I changed my default to 60,000 steps a week because I was afraid I wouldn't be able to do 10,000 steps a day for seven days straight. I was right, but I did beat 60,000! Go, me!

You can set daily goals for calories in/out (mine are 2100 to burn, 1500 to eat; this should result in a little over a pound a week of weight loss). There's a bar graph showing your calories in vs. calories out for the past 30 days.

I pigged out on Saturday... oh well!

The Activity section further dissects your daily activities by steps, miles, a pie chart of how active you were, and then a graph showing your daily activity in 5-minute intervals. This is what it looks like when you sleep in, get Starbucks, hike Mt. Rose (Lake Tahoe), come home, make dinner, run errands, do laundry, then sit down to write a FitBit review. :)

And finally, the sleep monitor:

A lot of people want to know how accurate the sleep monitoring is. It's been really accurate for me, but then again, I apparently sleep like a rock. This has been my most interesting night with the FitBit so far:

The dashboard, then, is where you really put together a picture of how you spent your day, both doing things and eating things.


This part of the site functions like many other sites out there. Like SparkPeople, in fact. :) You can search for foods in the database, enter your own custom foods with or without the additional nutrient info on the label, sort foods into Morning, Afternoon, Evening, and Anytime. You can also track walking, running, biking, swimming, or just about any other activity, from weight lifting to kneeling in church to sex. Yes, really. You can also track your weight.

The thing to keep in mind is that the website is very much still in development. Personally, I like this, because it means I can be involved in the end product. The FitBit team is very responsive to users, and is taking suggestions for website features in their Feature Suggestions forum. One such suggestion implemented in the first week was the ability to hide your BMI stats on the dashboard.

However, if you want 100% functionality NOW, then the following is a list of features that aren't on the website yet, but will very likely be added in the following year:


- Ability to browse user-input foods. Useful if you don't want to type in the nutritional info yourself, but you're positive that someone out there has already typed it in for themselves.
- Recipes. There is a "meal" function, but that allows you to name a group of items that you can then add to your tracker with one click.
- Protein totals. Seems like a big oversight, but right now your daily totals include calories, grams of fat, grams of fiber, grams of carbs, milligrams of sodium, and ounces of water.
- Subtotals per meal (e.g. Morning, Evening, Afternoon, Anytime, Meals)
- Not all major brands are in the database, but there are quite a few that I input that I was surprised to see on there. They're adding more food daily, and taking suggestions for brands to add in the forums.
- There currently isn't a diet calculator (e.g. "How many calories should I eat to lose 10 lbs in two months?"). However, they will soon be releasing something even better! A calorie budget, which will not only help you set goals for calorie intake and expenditure, but will include "rollover calories" to help you stay on track while splurging now and again.

Things I love about their food tracker:

- AJAX! You don't have to click the "save" button and reload the page every time you make a change. You can also drag and drop food items from one meal (Morning, Evening, Afternoon, Anytime), add to favories by clicking a star next to the item, delete items by clicking the X that appears when you hover over the item.
- The sidebar. It's an easy place to add favorites or meals to your daily food intake, and it also has a super handy Recent and Most Logged section where you can easily find food you recently logged and foods that you log frequently but maybe never bothered to favorite.

You'll notice in this screenshot that I hacked the Meals option into a makeshift Recipe category by inputting all the ingredients, then manually dividing each ingredient quantity by the number of servings in the meal.


- Missing an elliptical option! However, you can track running at a similar intensity for an equivalent calorie burn.
- No ability to share your activities via Twitter, Facebook, etc., like DailyMile

The Activities panel also has favorites, a "Programs" section that works like the "Meals" section in the food tracker, and a most logged and recent tab for those categories of exercises as well.


- Only tracks your weight in pounds. Will eventually let you track other measurements, which may include: body fat; blood sugar; body measurements (such as hips, waist, biceps, etc.)
- Has a historical graph of your weigh-ins; however, there is no trend smoothing feature as seen on Hacker's Diet, Physics Diet and the Google 15. Requests for such a feature has been noted on the forums.
- As noted in the Food section, there currently isn't a weight loss calculator; however, that feature is in the works, and it sounds like it's going to be awesome.


- I've never seen something like this, so I don't know how to critique it! This is the one tracking option that requires a FitBit. The only thing you can do in this tab is delete accidental sleep annotations.
- It also includes a bar graph of your hours of sleep per day for the past 30 days, and a companion graph showing how many times you wake up in the middle of the night, also for the past 30 days.

That's the tracker! Onto the FitBit Community.


Right now, the community consists of four forums: General, Feature Suggestions, Food Suggestions, and Help and Support. The good news is, the FitBit team is all over the forums and comments on questions, requests for support, and feedback very quickly. The forums, again, are lacking features that will be rolled out in the next year or so, including showing read vs. unread threads, private messages, a search function, etc. Why didn't they just use phpBB or vBulletin and call it a day, you ask? Because they can integrate it more tightly with the rest of the site by doing it themselves. I'm betting that you will eventually be able to show your most recent number of steps from your FitBit under your name, next to your avatar (not yet enabled) and post count (also not yet enabled).

Aside from the forums, the other community aspects that will be integrated eventually are friends and groups. An update feed and blog platform are possible as well; at least one user has created his own forum thread as a makeshift blog in the meantime.

Though there's a lot of work left for the FitBit team to create a fully integrated FitBit community, don't be shy to pop onto the forums to talk to other members. Us early adopters are a wordy bunch, and the FitBit team crawls the forums regularly.


Many requests have been made for an iPhone app. Currently, the graphs won't show on the iPhone because they are in Flash. I don't know how functional the site is on an iPhone because I don't have one. :( But on my Tilt with Opera Mini, the only function on the site I can use is logging favorited foods or activities.

They are also planning on releasing a public API. This will enable integration between the FitBit site and other sites, and also allow users to create apps that will crunch the FitBit data in an infinite number of ways.


Reset your FitBit:

Dock it, turn the dock over, and hit the button underneath with a pen or paperclip. The FitBit will reboot, displaying the current firmware version and the battery level, then will continue charging. This will not delete any of the tracker data.

Completely erase all information on your FitBit:

1. Put the fitbit on the base station
2. Look under base station and you'll see a tiny hole. That's the reset button that you can push with a small pen or paperclip.
3. Press and hold the button on the Fitbit itself and press the reset button
4. Keep the button on the Fitbit pressed for 6 seconds.
5. Take the Fitbit off the base station
6. Press the button on the Fitbit
7. It should say "Testing" and then "Pass"
8. Press and hold the button until it says "Erase"

Power Off Your FitBit:

Unplug the dock. Dock the FitBit on the unplugged dock, then press the reset button on the bottom.
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Member Comments About This Blog Post
    Thanks for a great review!
    2567 days ago
  • JO28352
    Great information. Thank you so much for sharing!
    2884 days ago
    Great information. I just order my Fitbit and plan to re-read this as I set it up.
    2916 days ago
  • no profile photo CD13755987
    Thank you for your extremely informative review!
    3045 days ago
  • no profile photo CD12259676
    You are so thorough, cool! I hope you are still enjoying yours. I got one for myself as a Christmas present. I have even forwarded this page to people wondering about the Fitbit. emoticon
    3099 days ago
    emoticon This was the best review I have seen on the FitBit. Are you still using it? What do you think now? emoticon
    3152 days ago
    Thank you for the infomation!
    3207 days ago
    I love my fitbit, it is so motivating to watch my flower grow and when it does not grow it seems to get me going. I have had it since the 2nd week of May.
    A little tip if you sign into myfitnesspal.com you can sync the site with your fitbit and mfp has a huge data base of food. I would love it if Spark would do the same but so far I have not heard of it happening. I miss my spark but recording my food an exercise twice each day is somewhat time consuming and I can use that time to exercise.
    Good luck all with your fit bit! Enjoy!
    3320 days ago
  • no profile photo CD12273509
    I love mine!!
    is there a group??

    The only problem:trying to log foods, etc. to two sites is getting onerous
    3325 days ago

    Comment edited on: 6/19/2012 11:14:55 AM

    Excellent article on the Fitbit - Thanks

    Just bought Fitbits for me and my wife.

    Looking forward to seeing what data I get for the high intensity Zumba classes..
    3326 days ago
  • TANYA602
    Awesome blog! You inspired me to send in my order this morning! I can't wait to get started!
    3336 days ago
  • no profile photo CD8939723
    I just ordered mine. Can't wait to get it on Thursday. Maybe I will start actually seeing something tangible that motivates me to get off my butt. emoticon
    3347 days ago
    Great and detailed article. I just got a Fitbit and was looking for a review like yours to make sure I'm getting the most out of my new little toy. Thanks!
    3348 days ago
    I've had my FitBit for a few weeks now and really get a lot of motivation out of it. It really offers a lot that Sparkpeople does not. For example, my walk to work of 1.7 miles actually involves a hill climb equivalent to 12 floors as tracked by FitBit. Sparkpeople treats it as a flat walk. My office is on the 7th floor of our building, and thanks to Fitbit encouraging me to walk, I can now get up those seven floors (equivalent to 8 Fitbit floors) in 1.5 minutes!

    The badges you get a kind of cool. I recently got my 1000 floor Skydiver badge, which was surprisingly exciting!

    We also just added to our Fitbit collection by getting their new ARIA scale, which syncs your weight and body fat with the Fitbit page. It is all totally free, although you can pay a fee to get more indepth analysis and a "personal trainer." You can also share your achievements with friends who are also on Fitbit. It is great.

    I used the sleep logging feature for about a week, and then stopped after that because my sleep paterns were pretty standard and I preferred to have my Fitbit at zero when I start my day. If there were some way to tell it to "start the day now" I would probably go back to using it. I also got bored with the whole process of putting the wrist band on at night.

    I do not show many things on my Public Profile, but if anyone is interested in what it looks like http://www.fitbit.com/user/234M2F You have total control over what goes here. It ranges from nothing at all to every thing you have done.

    One thing I forgot to add was that my wife and I have one each. With our old pedometers the steps were vastly different, even though we are about the same height, but with FitBit they are really close.

    I'd highly recommend it, and hope that Sparkpeople will support the data.
    3352 days ago

    Comment edited on: 5/23/2012 9:29:16 AM
    yes, thank you! I'm so glad you explained about the calories burned. That has been my biggest concern since I started wearing it yesterday.
    3358 days ago
    Excellent Post! I just purchased a FitBit yesterday and this was so informative. Thank you for putting it all together!

    3367 days ago
    I have one and I LOVE it. I forgot mine today and I feel so naked!
    3380 days ago
  • no profile photo CD12008355
    I just ordered this today, and I am looking forward to using it. I agree---very detailed review. I really hope it helps me get to my goal. Thanks!
    3390 days ago
  • MRSJ953
    Just got a Fitbit...loving it so far. Need a 2nd docking station.
    3395 days ago
    I just got a FitBit as a gift, 2-1/2 years after your blog. You can bet I'll be checking out to see if they've added the things you mention they will likely add. I think this will also be a GREAT reference tool for me. I'll be checking out the other review you mention you did also.

    Thanks so much for sharing!!!
    3403 days ago
    3451 days ago
    Be reading a lot today on the subject (fitbit vs BB). But the detail in this review is simply amazing. Thank you for all of the time, effort and attention to detail. I realize now that I did not know but an 1/8 of the features of the Fitbit.
    3454 days ago
  • KELSEY54
    Great review! I just ordered one and I hope it is problem free and as easy to use as you have written.
    3460 days ago
    Do you ladies who own this enter the food you eat in 2 separate systems. Do you Track in SP as well as fitbit software?
    3561 days ago
  • no profile photo MANSHMS
    I'd like to see the device upload information to SP.
    3570 days ago
    Terrific review!

    I have a FitBit and I'm a huge fan! I contacted the company with some concerns and they fixed it. Unfortunately, the replacement they sent me was broken and it took over a week to finally have the resolved. But, they sent me another one that worked fine!

    I am very happy with it!
    3703 days ago
    Terrific review!

    I have a FitBit and I'm a huge fan! I contacted the company with some concerns and they fixed it. Unfortunately, the replacement they sent me was broken and it took over a week to finally have the resolved. But, they sent me another one that worked fine!

    I am very happy with it!
    3703 days ago
  • KITT52
    thanks for the great review..I'm thinking about ordering one
    have you had any issues ..seems like this has been here a while
    3711 days ago
    Wow..great review. I just lost my mytrak yesterday, and know it is gone forever. I need to get another, and was checking different models. I just may go ahead and order this one.thank you. diana
    3719 days ago
    I HATE the Fitbit. Mine never worked right, contacting customer service (which is only by email) was a joke. It took over a week to get a useless response from anyone. I contacted my credit card company and had them reverse the charge to finally get a response from these people. They then exchanged my fitbit for another one that didn't work right either.
    I never found it to be even close to accurate (I went to work, did errands and then ran 4 miles on my treadmill and the device logged 2.21 miles for the entire day). Waste of money from a company who ignores the fact that these devices are defective.
    3750 days ago
    Super informative. Thanks!
    3818 days ago
  • no profile photo NJSWEETS
    Someone replied saying she prefers this over the Body Bugg. I'd like to know what the difference is and why. I'm going back and forth between the 2. Thanks!
    3844 days ago
  • MOODY9
    Great review! I love my FitBit! :)
    3921 days ago
    Wow what a great review. I've had my Fitbit for 3 days now and am really enjoying it. I get a little frustrated with the site but I can't expect everything to be as great as SP and they are so new so I will give them a break.

    And they sell them at Best Buy now so I think the ordering problem might be worked out!
    3931 days ago
    Are any of you aware of the possible ramifications of the website? I seem to think that any info on your computer can be accessed by this. Hope I'm wrong, but it seems like leaving your home and handing the burglar the keys,. emoticon
    3953 days ago
    Thanks for this review -- how do you feel about fitbit now?
    3960 days ago
    Personal favorite...thank you for this review!!!!
    3962 days ago
    See you wrote this review some time ago - wondered if you still used your FitBit and what your impression of it was now? Ordered mine tonight. hopefully I will see it soon.
    4023 days ago
    Thanks for the review. Although backorded I ordered it tonight. Looking forward to this new item.
    4030 days ago
    Thanks so much for the information in your technical review. I refer to it often. FitBit had very minimal instructions and I had a very difficult time getting started. Finally, I got online with a real person from FitBit who patiently walked me thru setting up and getting started. I would have returned the whole package if not for you and that nice young man.
    4058 days ago
    Thank you for the review. I just got mine today and am very excited about it!
    4064 days ago
  • no profile photo JFFRIEL17
    Bought mine back in March, it arrived last week and completely failed this morning during a 5k run. Screen went blank, won't reset, won't charge the battery, etc... I had a bodubugg for 3 years before it failed back in February. Replaced it with the fitbit on the recommendation of prevention magazine. Price was surely more attractive, but now I have nothing after only a week. I have contacted the fitbit support team about a replacement, but with the backorders, I probably won't see it fo a some time. Very disappointed becasue when it was working it was great. emoticon
    4070 days ago
    Wow, this is an excellent review. I am so glad that you like it. I ordered mine about 6 weeks ago and am STILL waiting for it to ship. They are 'currently filling back orders' and say I can expect mine around June 15th.

    I also work a desk job and I think this will be a great motivator for me to get up and move around. Keep us updated!!
    4088 days ago
    Wow, this is an excellent review. I am so glad that you like it. I ordered mine about 6 weeks ago and am STILL waiting for it to ship. They are 'currently filling back orders' and say I can expect mine around June 15th.

    I also work a desk job and I think this will be a great motivator for me to get up and move around. Keep us updated!!
    4088 days ago
    Wow, this is an excellent review. I am so glad that you like it. I ordered mine about 6 weeks ago and am STILL waiting for it to ship. They are 'currently filling back orders' and say I can expect mine around June 15th.

    I also work a desk job and I think this will be a great motivator for me to get up and move around. Keep us updated!!
    4088 days ago
    Wow, this is an excellent review. I am so glad that you like it. I ordered mine about 6 weeks ago and am STILL waiting for it to ship. They are 'currently filling back orders' and say I can expect mine around June 15th.

    I also work a desk job and I think this will be a great motivator for me to get up and move around. Keep us updated!!
    4088 days ago
    I am so frustrated. I ordered mine 2/13 and was told it would ship today. Now it says won't ship til 4/30 I am seeing stories of people waiting 13months or more for one. I refuse to pay $200+ for one on ebay. This really sucks. I checked the microsoft store like someone posted but they are out of stock. Some other websites say not shipping til 6/2010.
    I hope it is worth the wait once i finally do get one IF I ever do get one.
    4136 days ago
  • no profile photo OLDQUILT
    I am very frustrated by the fact that I ordered this back in November and haven't received it yet. I guess they are filling backorders by grabbing orders off the top of the pile instead of the bottom. When I E-mail them to ask when mine will be shipped, they just add another month to the last estimate they sent me:-(( emoticon
    4138 days ago
  • _MAOMAO_
    Thx for the great tech review! CODYJO2009 referred us Sparkers here from the new Secrets of Success section.
    4140 days ago
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    Disclaimer: Weight loss results will vary from person to person. No individual result should be seen as a typical result of following the SparkPeople program.