Fitbit Flex vs. One Review

I recently bought the Fitbit Flex and the One to do a side by side comparison to decide which device was going to work best for me. I will admit that my preference was skewed to the Flex as I am less likely to lose the device (or put it in the wash) as I am with the One.

The lack of display is not a factor to me as I set the status lights on the Flex to display my calories burned as that is the goal I am most interested in seeing. It breaks your goal up into 5 increments and when you reach 1/5 of the goal the first light appears when the face is tapped twice and so forth. This was enough for me. I could always log on to fitbit to get true data points when ever I was near my computer.

I wore both devices for 7 days and planned on a 10 day trial period. At various times each day I would sync both devices to the website to compare data. I found that in most situations, the Flex over calculates the steps taken and therefore over calculates the calories burned for the way I would use the device.

I wore the Flex on my left (non dominant) wrist and the One clipped to my bra in the center. I calibrated each device with my walking stride length. I used all day everyday in all types of conditions. Sometimes I would keep the flex in my pocket by mistake after washing my hands or some other time that I would take it off.

I discovered when used during exercise (worn on the wrist or in my pocket), the devices were comparable in numbers (cals burned, distance traveled, and steps taken). At least the numbers came out close enough to each other that it was acceptable to me. Also, the Flex would be close to the One when the device was in my pocket during non exercise times.

When I wore the Flex on my wrist, while carrying a purse or other item the Flex would calculate more steps than the One. It would over estimate my mileage walked each day as well.

As an example, yesterday I walked 3.5 miles according to my calculations of where I traveled. I was leisurely walking with my purse in my hand. Sometimes in my left hand, sometimes in my right. I was talking on the phone while walking as well.
My data points for this day are:
One - 11:30 am
3.5 miles
Burned 1251 from midnight to the time I synced the devices
Walked 7955 steps.

Flex - 11;30 am
4.25 miles
Burned 1545 cals for the same time frame
Walked 10295.

I then took a 1.5 mile walk without carrying my purses or using the phone.The data from this information is comparable between the devices. My data points were:
One - 1:30 pm
5 miles
Burned 1557 from midnight to the time I synced the devices
Walked 11672 steps.

Flex - 1;30 pm
5.75 miles
Burned 1860 cals for the same time frame
Walked 13347.

I did a workout session at the gym ended the day with the following figures:
One - 9:30 pm
6.75 miles
Burned 2765 from midnight to the time I synced the devices
Walked 16105 steps.

Flex - 9;30 pm
7.5 miles
Burned 3126 cals for the same time frame
Walked 18370 steps

I thought this was an anomaly and was going to give it another try today but this afternoon, I was sitting with a friend when I did a sync of both devices to see where things were for the day. There was the discrepancy between the numbers but until I get do more testing, I could not give up on the Flex altogether. However, after talking with my friend for 30 mins, I did another sync of both devices. The Flex was 200 steps higher than the previous sync. The One however had not changed. And it should not have as I did not get on my feet one single time in that 30 mins. I did not move from the chair I was sitting on except for the fact that I was talking and therefore using my hands as part of the conversation.

The Flex calculated my hand gestures as steps and thus had my counts way off. It is my belief that the flex over estimates the steps and cals burned when carrying stuff in your hands or excessively moving the arm that the device is attached to.

I immediately took off the Flex and will be returning it once I get time to go back to Best Buy. Its not the right device for me. If I wanted to be more accurate and stay in my pocket, the One is that device.

If I were a man or a woman who does not carry a purse then maybe the device is more accurate but since I nearly always have a handbag, the Flex is not going to give me an accurate read out.

Both devices are able to measure your activities and give you the cals burned estimate. But unless the device is accurately giving the info sought, it is not going to help in the weight loss plan I am trying to achieve.

Conclusion - the Fitbit One is the device I will keep and will have to do my best to make sure I transfer it from my clothes and make sure it does not get washed. I feel that it accurately gave me the information I was seeking.

I hope this helps someone who may be on the fence about which model to buy.
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Replies

  • niks514
    niks514 Posts: 11 Member
    Thank you for this post!! I had told my husband I wanted the flex for my birthday last week and I admit I was a little disappointed when I opened my gift and found he had bought me the fitbit one --- he said he researched and found the one to be much better in most reviews and decided to get me that one -- and I LOVE it!! You post just makes me feel better with my gift!!
  • SuperStepper408
    SuperStepper408 Posts: 15 Member
    Thanks for this post. I've been trying to decide which one to buy and what the differences are since I know very little about HRM's. I think you explained it quite clearly and now I will get the Fitbit One instead of the Flex.
  • FitFunFabulousNicole
    FitFunFabulousNicole Posts: 94 Member
    Wow! This post came at a perfect time for me - Thanks for the comparison :)
  • AliandTrev
    AliandTrev Posts: 194 Member
    Thanks for that, I was wondering about the Flex. Thinking mainly that I wouldn't throw it in the washer as easily. I have know washed my FitBit One twice now and luckily it has remained unharmed by that. It did however calculate that I climbed 10 flights of stairs yesterday after it's ride in the washer/dryer.
  • GeekAmour
    GeekAmour Posts: 262
    Thank you for this post!! I had told my husband I wanted the flex for my birthday last week and I admit I was a little disappointed when I opened my gift and found he had bought me the fitbit one --- he said he researched and found the one to be much better in most reviews and decided to get me that one -- and I LOVE it!! You post just makes me feel better with my gift!!

    Big ups to hubby for doing some research! I luff my one, too.
  • kristafb
    kristafb Posts: 770 Member
    I was waiting for the Flex to come out but got impatient (as I usually do lol) and bought the FB one & I love it!! Thanks for the review!
  • alisonsurf
    alisonsurf Posts: 92 Member
    Thanks for th review! I was feeling regret that i didn't wait to get the flex especially since I had so many troubles with the first fitbit (they sent a new one!). :happy:
  • jezama77
    jezama77 Posts: 138 Member
    Thanks for this post. I've been trying to decide which one to buy and what the differences are since I know very little about HRM's. I think you explained it quite clearly and now I will get the Fitbit One instead of the Flex.

    Neither device is a heart rate monitor. Both are high tech pedometers with a few extra features. I have researched a TON of these type devices. I have decided to do more research and get a heart rate monitor, but I might wait a bit and get an amiigo since these actually seem to measure more than just steps...

    Here is the link: http://www.indiegogo.com/projects/amiigo-fitness-bracelet-for-iphone-and-android
  • donnaleighh
    donnaleighh Posts: 178 Member
    Awesome review ..... you might find this one interesting as it also compares One with Flex and it looks pretty consistent with your own analysis

    http://www.gizmodo.com.au/2013/05/fitbit-flex-review-peer-pressure-sucks/


    :)
  • hannah0419
    hannah0419 Posts: 1,069 Member
    Lucky Days- Thanks for the review… I have had the fitbit ultra for about 2 years and the Flex is now on it's way in the mail to me. Your review is troublesome; I was so looking forward to the flex. I really appreciate the work and research you did.

    One question: Did you have any trouble setting up a 2nd device to sync? Did you open a new email account or how did you handle that? I plan to use them both for awhile as you did.

    Again, thank you.

    Hannah
  • hannah0419
    hannah0419 Posts: 1,069 Member
    Thanks for that, I was wondering about the Flex. Thinking mainly that I wouldn't throw it in the washer as easily. I have know washed my FitBit One twice now and luckily it has remained unharmed by that. It did however calculate that I climbed 10 flights of stairs yesterday after it's ride in the washer/dryer.

    Allan- I also have washed my fitbit ultra twice (front loading washer) and it is working okay except for flights of stairs. It WAY over calculates how many flights I've done.

    Hannah
  • Perfect timing on this post - I'm interested in investing in a fitbit but I didn't know which one to get and how useful it really is.
  • HappyElizabeth
    HappyElizabeth Posts: 231 Member
    Thanks! This is really helpful. I've had the Fitbit One for about 6 months and absolutely adore it, but wanted to buy the Flex because I'm a sucker for the latest and greatest of anything. But, really, you've proven to me that I don't need it, and that the One is actually the better unit accuracy wise. I've never had an issue with losing it - I always keep it on my bra. (FYI - I have worn it with a HRM and since the activity I do is mostly step based, there was almost no difference in calorie burns, so I've stopped wearing the HRM except for cycling)
  • The Fitbit One may be a fine device but I believe the Zip may be their best. After reading this you may feel the same:

    http://mandatory-tech.com/2013/05/09/fitbit-zip-the-least-expensive-fitbit-may-be-their-best/
  • luckydays27
    luckydays27 Posts: 552 Member
    You are all welcome. I was to impatient to have someone else do the review and had the extra $ to buy both. (with the knowledge that one of them would be returned).

    As an FYI, I use a HRM (Polar FT60) while working out and now leave the Fitbit in my bag. I do it this way because the HRM determines my cals burned as I do a cardio/circuit training mix. The fitbit cant accurately measure my cals burned so I leave it alone for that time. As soon as the workout is over though, I put the fitbit back on. My previous test data with the fitbit on while working out was to determine if the steps taken/cals burned matched each other.

    As for how I handled syncing, I started two accounts on Fitbit.com with different email addresses (I have several). The account for the One was synced with MFP and the Flex was on its own. I entered all my info into MFP to sync with the One and manually entered my fitness cals burned on the Flex fitbit account. that is how I was able to keep my data points consistent.

    For those that think the Fitbit is a glorified pedometer, I guess you can look at it that way. I dont, I see it as an activity tracker so I can know how many cals i should eat each day based on my activities each day. I have a sedentary job so for the most part I sit all day and dont do much. But I also have appointments and meet clients often so on those days, I am far more active. because I live on that side of laziness, I like having a device that takes my activities and tells me how much I am supposed to eat/how many cals I burned. This makes living my life, the way I do, easier. I think this is the best $90 US I spent on diet/exercise/fitness etc in a really long time.

    Good luck to all of you. If you have questions let me know.
  • I have the Flex and love it. Returned the One to get it as I kept forgetting to take the One off my bra!! I am also keeping track dually. I believe in wearing my HRM while doing cardio and putting in those calories during that time. I can still wear my Flex (or the One) as you can enter your data manually for the workout time, the FITBIT will readjust what was recorded during that time - so no need to take it off your wrist.

    When I sync FB with MFP my manually entered exercise gets moved onto MFP.
    I compare the calories that are still available, realizing that FB will show more as it monitors ALL my movements. I don't usually use those but it motivates me to move more!!!
  • mdmcavoy
    mdmcavoy Posts: 1 Member
    Interesting and informative comparison. Thank you very much for posting that.

    I agree that the Flex is not terribly accurate, but if you do not need the precision, and if you are not making eating decisions based on the information ("Gee, I've hit my goal, so I can eat extra!"), don't discount the Flex. The Flex wins hands down for convenience. Aside from charging it once a week, I put it on and leave it on (through showers, dishwashing, sleeping). No more leaving your Fitbit clipped to that other garment (the one headed to the washing machine) or having it fall to the floor while adjusting your clothing in the bathroom.

    I use my Flex primarily to encourage me to move throughout the day, and to work with MyFitnessPal to give me a ballpark sense of whether, overall, my eating decisions and activity levels are moving me toward my goals. I was surprised to find that the sleep monitoring has become very useful for me, showing a recurring pattern to waking up in the middle of the night that I discovered was due to a neighbor's (noisy) late-night routine (they slammed their car door at around 2:15 a.m. most nights).

    (For what it's worth, my Flex is underreports my steps about as much as it overreports them. I spot check periodically out of curiosity by syncing the device, noting the steps on the dashboard, then walking for a distance and counting my steps. I have not done a long-range comparison, nor one as exquisitely detailed!)
  • Antlady69
    Antlady69 Posts: 204 Member
    Very interesting. I wonder if your results had been different if you had worn the Flex around your ankle? That's what I plan on doing. I always feared that arm movement while being stationary would influence the readings.

    Thanks for the review!
  • 777twist
    777twist Posts: 75 Member
    I almost bought the Flex, but then read a lot of reviews saying it was off on it's counts. Since I didn't care to wear it on my wrist, the ONE looked like the best bet.

    I love it. It works great. And I do much the same as you, in terms of taking it off and using my HRM for workouts.

    It is just a pedometer with some extra features... the main difference being it syncs to an account and does the math for you on your steps, elevation, etc... I'm not knocking it, I love mine. But it's not splitting atoms over here. ;-)

    But to be honest... I really love my Heart Rate Monitor. I have the BlueHR by Wahoo, and it works great with my iPhone and Digifit.

    Everything I have seems to talk to one another, which really helps so I don't have to enter things multiple times (or sometimes at all).

    I do think the calculations that FitBit uses are wrong in the grand scheme of things... because from what I can tell they use a daily average to predict the rest of your day. But I think they should break the day up into sections, and then use those section averages to predict. I can't tell you how many times I have earned extra calories early in the day, only to watch them run down close to zero, to zero or below because I'm not doing jack in the evenings. That's a flaw, and I sent them an email about it. But it's not a deal breaker by any means. Just be aware that if you earn extra calories early in the day, don't eat them all up if you are just going to sit around at night. You may end up going negative if you do that.
  • lv186000
    lv186000 Posts: 1
    Good job testing, really appreciate the data and results!
  • luckydays27
    luckydays27 Posts: 552 Member

    I do think the calculations that FitBit uses are wrong in the grand scheme of things... because from what I can tell they use a daily average to predict the rest of your day. But I think they should break the day up into sections, and then use those section averages to predict. I can't tell you how many times I have earned extra calories early in the day, only to watch them run down close to zero, to zero or below because I'm not doing jack in the evenings. That's a flaw, and I sent them an email about it. But it's not a deal breaker by any means. Just be aware that if you earn extra calories early in the day, don't eat them all up if you are just going to sit around at night. You may end up going negative if you do that.

    Make sure that you are set to sedentary in the food section under Change your Daily Calorie Estimate Setting instead of personalized. Sedentary starts you out low and allows you to earn more as you are active in the day. Once you sync up, it then continues to increase your cals burned/intake at the sedentary pace. If you are active it increased your cal burn/intake accordingly.
  • 04ward
    04ward Posts: 196 Member
    I love my Fitbit One and LIKE that I can look at the display throughout the day to check my progress instead of always logging to the site! If anyone is interested in purchasing any of the Fitbit products, go to this Groupon link http://www.groupon.com/deals/brookstone-2-atlanta and buy the Brookstone Coupon "$25 for $50 value". Then when you go to the Brookstone site, you can apply the groupon as a gift card when you check out and get $50 off the price. Also, make sure you enter the Promo Code on the Brookstone site of "20GIFT" and it takes ANOTHER $20 off!

    I just bought two this way to use as giveaways for a Fitness program and with Tax and Shipping I had out of pocket of $46.51 for the Fitbit One and only $22.92 for a Fitbit Zip!
  • 04ward
    04ward Posts: 196 Member

    I do think the calculations that FitBit uses are wrong in the grand scheme of things... because from what I can tell they use a daily average to predict the rest of your day. But I think they should break the day up into sections, and then use those section averages to predict. I can't tell you how many times I have earned extra calories early in the day, only to watch them run down close to zero, to zero or below because I'm not doing jack in the evenings. That's a flaw, and I sent them an email about it. But it's not a deal breaker by any means. Just be aware that if you earn extra calories early in the day, don't eat them all up if you are just going to sit around at night. You may end up going negative if you do that.

    Make sure that you are set to sedentary in the food section under Change your Daily Calorie Estimate Setting instead of personalized. Sedentary starts you out low and allows you to earn more as you are active in the day. Once you sync up, it then continues to increase your cals burned/intake at the sedentary pace. If you are active it increased your cal burn/intake accordingly.

    I set mine on Personalized. I tried the sedentary but I work a lot of night shifts at my restaurant and we would have a really busy night and at 11:00, it would show I was WAY behind on eating calories. By setting on personalized, it takes an average of what my past history was and somewhat guesses what I need to eat for the day and if you swipe to the second screen of that section of the site, it shows actual calories burned and eaten so it shows you exactly where you are at that particular point.
  • swfoster
    swfoster Posts: 1
    Thank you!! I have been trying to decide which one to get. I think I will go with the One as well.
  • C00lc0le
    C00lc0le Posts: 2
    Thanks so much for this comparison. The button fell out of my One and since I bought it from Best Buy I was going to exchange it for the Flex; however, after reading this, I'm just going to swap the One instead.
    - I'm not a fan of wearing anything on my wrists.
    - I'd prefer the more accurate calorie count.
    - I had a Nike+ Fuelband and didn't care for it being on my wrist and it seemed to greatly over-exaggerate the effectiveness of my activity. (Sounds like the Flex will have the same issues).
  • Hello! Well I've just bought my Fitbit One a few days ago. I thought I'd post a couple of things I'd found! Firstly I find it very accurate with steps. I did a few trials of counting my steps while walking and found it accurate to one or two steps but most times absolutely bang on so that's really great. It also is accurate with kilometers to my RunKeeper so very happy with all that. Also driving has been no problem and it has so far not logged any extra steps even on bumpier roads (but I live in Holland and even in the countryside here the roads are never that bumpy!) Going on holiday to the west of Ireland soon so we'll see!!!! I've had no problem with the clip as has ben reported. I wear it on the front of my bra and it might as well be superglued there! It's a big pull to get it off at night! The only amusing thing is my husband laughing as I peer down my top at intervals to check it while I was doing the counting/ driving tests......! I was fascinated by the Flex but as I have a few Border Collies my day involves a LOT of walking and doggy activities and I was worried that the Flex would misread due to holding dog leads or throwing frisbees, playing tug, using hand signals for the dogs and the general 5 hours at least of doggyness a day. The Fitbit one has been great for all this. I do however use MFP for foods etc as I have been using it a long time and just really didn't want to change. I can completely recommend it for all this.

    The problem is the sleep thing. Okay, so I didn't buy it for the sleep thing but I thought that would be really nice to see. I am a poor sleeper. I take a long time to fall asleep and wake up a lot during the night. Lots of things wake me up (any outside noise etc) and in that I include the dogs who all have their own "thing" to freak out about. One is terrified of thunderstorms, one curtains flapping in an open window in wind, one the postman opening the gate too loudly and another the fighter jets practicing maneuvers. Well this week we've had it all.... I put my Fitbit in it's pouch and settled down to sleep. I know it takes me a long time to get to sleep. I can be lying in bed for up to an hour, glance at the clock and see the time. Fitbit told me I went to sleep in 5 mins. Hmmmmm.... I think not..... When I try to go to sleep I try to relax and not flail my arms about wildly. So first thing I was logged as asleep over 55 mins before I actually was. As a test I was watching my awake/ asleep times for the past few nights. When I actually have to physically get up out of bed to do something like close a window or tell a dog to go to their "safe place" (the puppies are still a nightmare!) Fitbit acknowledges I am awake. On one particular night/ morning I was woken up 5 times. Once I had to get out of bed to close a window. The other times I had to verbally correct a dog but stayed in bed. One time it took me an hour and 15 mins at least to get back to sleep. The others maybe 15 mins to half an hour. I know it was actually longer but that was the last time I noticed at the clock. Fitbit told me I had woken once (the time I got out of bed and the other times I was "restless" for about a minute. I was in bed for 9 hrs and 16 mins. According to Fitbit I had a blissful 9hrs and 8 mins slumber with a bit of restlessness. With my eyes on a clock I had at most 6 hours and 15 mins sleep. As I mentioned I do not flail my arms around when awake in bed so it picked up nothing. I will not be using the sleep function anymore but I dearly wish I could turn that damn stopwatch into an activity tracker so I could hit it when I take off at an agility course or a frisbee long distance event and track the time of that properly while I'm running around like a fool! In those situations the stopwatch would be great, even to track my course times. It would be lovely on the website to disable this as a useless sleep tracker and use it for something that we be of benefit to me! Also the tracker resets at midnight every night. I am never in bed by midnight as I have to work with companies from abroad and am often awake till 5am here. Pity you can't set your own day set at your bedtime.... Maybe I should have just bought a more basic pedometer!

    Anyway, enough of that. I didn't buy it as a sleep tracker (luckily) but if any of you are basing your decision for purchase on this function then really don't!!! I am a bit sad because I was quite taken with the idea of the function. Other than that for day to day doggy stuff for doggy people then it's great. It also helps me track my 12 year old doggy lady and her fitness as she does what I do so I can keep her going on her "elderly lady fitness"!
  • luckydays27
    luckydays27 Posts: 552 Member
    You can use the sleep feature to track timed activities. Just push the button when you start and end. Go to the fitbit site and categorize that activity.

    I dont use the sleep feature anymore either. I am a great sleeper and always have been. I know that I go to sleep in 10 mins or less (usually less than 5) and will sleep soundly for the night.

    Some people call it a glorified pedometer and I can see their point but the syncing feature and estimating cals burned for the day makes this thing the bomb for me.

    *****my one month update with using the One****
    I love my fitbit. I still wear it everyday and would imediately go buy another should I ever lose it or it breaks. I still use my HRM for fitness as I do circuit training, weight training and some cycling so the fitbit cant really measure these activities well.

    I have found that I am far more sedentary than I ever thought most days so having the One sync with MFP has really helped me keep my cals to eat in check.

    I started with the One around May 10th at 193 lbs. Its been about 6 weeks and I am at 185. That's 8 lbs in 6 weeks and I could not be happier. I am eating more which, IMHO, has been the key to my weight loss so far.

    I have been so happy with it that I bought my fiance and my sister one.

    My only tip is that for women who wear this, to avoid the fitbit falling out of the case, wear it clipped to your bra in the center but wear the fitbit display is actually between your bra and your skin. The thing cant fall out since its wedged in there. For guys, my finance wears his on the waste band of his underwear also facing in so the display is touching his skin.
  • lewkowicz
    lewkowicz Posts: 1
    LOVE this very thorough review - I just received the One yesterday and then decided to look at the reviews (backwards, yes, but that's how I live my life!). You did a great job of conducting a mini-research project, comparing the results, and offering hypotheses as to why the One and Flex gave different data. I would prefer to underestimate than overestimate my activity levels, and I loved your data. Makes me feel great that I bought the One (I was also surprised with the sleep feature - I've been having sleep issues lately, and it's giving great details).

    Thank you.
  • Dlacenere
    Dlacenere Posts: 198 Member
    Wow, awesome comparison - thanks! I have used a one since October and for Mother's Day my husband got me a flex. I wore them both for two days and found the same thing, the flex gave me more steps than the one and thus a higher calorie burn even when I counted my steps, the one was correct and the flex was high, so I returned the flex and still am in love with fitbit one.
  • BobOki
    BobOki Posts: 245 Member
    Not going to go through all the posts, but please keep in mind there are multiple settings, including sensitivity you can set on the flex, please try them and review again!
    Great review btw.