4 Surprises I Had While Using the FitBit

Last month, I bought a Fitbit charge.  I never intended to buy one for myself but after researching the different models for a gift, I thought the FitBit sounded interesting.

I have always wondered how much running burned as well as random gym equipment, etc. I decided to purchase one for myself and see how I liked it.  I didn’t know what to expect!

Click to Tweet: Four Surprises I Learned While Using the FitBit 

Fitbit Charge with Heart Rate

First surprise: Overestimating Calorie Burn

Keep in mind; I think knowing how many calories you burn is important, but I don’t believe any athlete should focus on calorie burn. 

Occasionally I’ll supplement the AMT into my running routine.  The AMT always told me I burned between 500-600 calories per hour.  I was shocked to find my Fitbit stating I burned a whopping 131 calories.    I knew cardio machines were inaccurate, but that is a huge difference.  Do I think FitBit is perfect?  No, but I do believe it’s more accurate than machines at the gym… 

Interestingly enough I found this article about how Sara Hall only burned 1500 calories during her marathon.  I know smaller framed runners burn less, and I don’t burn 100 calories per mile.  I’m 130 pounds and 5’7.  I normally “guestimated”, I burned about 75 calories per mile and so I ate between 2500-3000 calories daily.  I don’t track it because it’s honestly too much work and I was running fine and not losing/gaining weight.

I decided to take a deeper look into my Broad Street 10 mile data.  I ran Broad Street in 1:01.59, however, since my heart rate was high, FitBit concluded my run was an additional 30 seconds longer.  For 10 miles, you would think I burned 1000 calories or in my “guestimating” 750.  In reality, I burned around 583. 

broad street calories

Second surprise: Distance I walked at work

Sometimes at work I end up walking 10,000 steps. I wouldn’t have thought I walked that far. We have two floors at several locations, and I find myself climbing steps more than I expected.

Third Surprise: My Steps/Mileage isn’t always accurate

I wore my Fitbit during the Broad Street 10 miler.  After the race, FitBit said I ran about 9 miles for the entire day.

Broad Street is a certified 10-mile course, and I had probably walked another mile beforehand.   For me, I have a shorter stride, and FitBit doesn’t always pick up on it.

I don’t think FitBit is 100% accurate in picking up steps and distances traveled.

Fourth surprise: I’m way more invested in Sleep and Heart Rate

Fitbit Charge with Heart Rate

I run with my Fitbit on and to be honest; I don’t care about steps.  I know I’ll hit 10,000 most days I run but even if I don’t…I don’t get upset or try too.  I don’t ever feel more or less motivated to get up and walk.  I didn’t purchase Fitbit to motivate me to move, I purchased it to track data and learn more about my habits.  Since buying my FitBit about a month ago, there hasn’t been a day I’ve paced around the house or walked around at night to get more steps.

I’m also far more invested in my heart rate.  I’ve always wondered what my heart rate is like while running or resting.  It’s been great data to track.

Do I like FitBit?

FitBit Charge

I do. However, it’s not data I get overly concerned or lose sleep over.  I like to know my sleep habits as well as my heart rate the most.  It’s interesting but like any technology, it’s not 100% perfect.  It’s a better picture of your overall fitness.

Disclosure: I purchased my own Fitbit and am not getting paid to review it. 

Funny Articles Related to FitBit:
19 Real and Emotional Struggles to Having a Fitbit
What it’s Actually Like to Own a FitBit 

Click to Tweet: 4 Surprises I had While Using FitBit

Questions for you:
Are you part of the Fitbit World?
Do you monitor your sleep or heart rate?


  1. Interesting. I guess the Fitbit is calculating calories based on heart rate and steps? I wonder if there is more to the equation that would not be reflected in heart rate — maybe not. I have the Garmin version and I’m not sure why I still wear it all the time. I never look at any of the data, but I like knowing it’s there if I want to!

  2. I have a Vivofit and found wondering about the same things.However, I stopped wearing it when I sleep. I feel like I need a small break from technology. But when I did sleep with it, I was flabbergasted how much I move throughout the night! Who would have thought!

    I don’t think having it has a great impact on my workouts, I workout the same, but at the very beginning, it did force me to move a bit more at work and go outside for lunch walks. Oh, and it was great to have in the latter stages of pregnancy when I was getting tired a lot. It kept me moving!

    PS. You are taller than I thought lol!

  3. I LOVE my fitbit but I’ve definitely noticed some of the same things. I was using my fitbit to track my time when I was running but then when I used the Nike+ app, I noticed the FitBit was consistently short changing me! (So I was running faster than I thought!) Still, I love tracking my steps because it motivates me to move during the day. I usually sit at a desk all day so I really have to be conscious about moving!

  4. I reviewed the fit bit a few years ago. While I don’t think the product is for me, I think it’s very interesting sometimes to see the data! it’s definitely not accurate (I don’t think any of them are) but it’s good to see on some level. I found with the fitbit that I was burning more than I thought over a full day! but yeah, distance is hardly accurate – I use mapmyrun for my runs and it varies against the step mileage tracker of my phone. I try to ignore that feature on my phone by the way. too many numbers!

  5. I’ve had a fitbit flex for over 2 years now. It doesnt track my heart rate and I am considering upgrading pretty soon. However since I had it with my last job where I drove to work and bately moved and have since changed jobs that involves walking to the train and more getting up during the day it has been interesting to see the step differences. Even though not 100% accurate, it does encourage me to move more. I love seeing my sleep patterns as well. I cant wait to upgrade and see how my heart rate is through my activities.

  6. I love my Fitbit HR, but I take everything was a grain of salt. For example, I use it mostly for steps and sleep. I don’t use it for mileage or floors. I also like using it for comparison purposes, so I can see one day over the next if I’m more active or not active. And while I know its not entirely accurate, I do like using it for heart rate monitoring. I’m supposed to somewhat watch my heart rate while running and pregnant, so I like to take a look at that every so often.

  7. I’m sure some other commenters have already pointed this out but the FitBit can definitely be inaccurate. And, as far as “counting” steps, it actually goes by wrist movement. Yep. So say, when I’m grocery shopping my Garmin vivoactive will tell me to MOVE because, even though I’m obviously walking all over the store, I have both hands on the shopping cart, not moving. I have also achieved my step goal while driving since I’m moving my hands on the wheel, etc. Crazy.
    You have to just take that stuff with a grain of salt. However, for tracking my swim, run and bike, my Garmin vivoactive is SPOT ON!! 🙂

  8. I’ve found similar – I’ve tried both Fitbit and Misfit, though the lower end models without HR. Both varied a good amount in terms of steps/distance. Just last week I got a Garmin Vivoactive so I’ll be curious to see how I like that over time. I mostly got it for running and swimming, but have actually been wearing it all day so far, for the steps. Sadly, I am one of those desk-job people who ends the day with a paltry 3k in steps most days, and have to go home and hoof it out to get a decent number of step in! Wish I had a more active job.

  9. I just got a garmin that has a step counter. I think it way overestimates the steps. I was sitting down and it calculated i walked 50 steps. um, no, no i didn’t. i got the watch for the garmin/running/swimming/biking calculating distance and pace aspect not for the steps. although i did find it interesting at first to see. my friend has the same watch and he asked “so how many steps are you walking?” he wants to get into a competition and i am NOT playing that game. i just said “i’d rather not say” and left it at that. i think it gets dangerous and not fun when it becomes a comparison thing. i’m just so not into that.

  10. Charm City Run just got us the new garmin vivoactive HR for a staff competition and I spent all weekend playing with it. I’m not sure how accurate some things are, but it’s definitely interesting to see that some things are overestimated. I try not to get too wrapped up in the numbers, but I do find it interesting.

  11. I always like reading about people’s experiences with these fitness trackers. I got a FitBit a while back as a way to track my steps since I work from home and it can be hard to get those steps in daily, and I used it for a little while but the novelty kind of wore off and I haven’t used it in months. I did like the sleep tracking though, and it definitely encouraged me to move a little bit more.

  12. I have the Fitbit Charge HR and I love it! I agree, the distance of my runs is never accurate and neither is pace. The data about sleep is so interesting to me and same with heart rate. I’ve had it for almost a year and am still such a fan of it.

  13. Hi Hollie,
    My fitbit always says I ran a shorter distance than I do too, and it’s usually about a mile off. I would say it encourages me to move more on rest days, but those are few and far between. Even though it’s inaccurate, I do like wearing it.

  14. I love my fitbit. I don’t get overly concerned with the numbers because some days I will have 30k steps and some days I get to like 7500. It all evens out. What I really like it for is sleep tracking. Its so interesting to see how much I was tossing and turning or resting peacefully at night. My fitbit tells me that I’m short on miles too. If I do a 5 mile run, it might tell me I have 4.85 miles for the entire day, so I do believe that’s off some. Calorie burn is depressing. It’s amazing how off the cardio machines are. I used to assume I was burning about 100 cals every 10 min on the elliptical but in reality, I burn maybe 175 in 30 minutes. Maybe!

  15. Like you, I don’t find wearing my FitBit will make me more likely to pace around my house. I generally walk to and from work, and walk or run at lunch or after work, so for the most part, I’ll hit my step goal.
    I find the HR data really interesting, especially after running Dopey when it took 3 weeks for my heart rate to settle at my normal resting rate. It just shows even though I felt recovered, my body wasn’t.

    1. That’s really interesting Ange, thanks for sharing. That does sound like a lot of walking!

  16. So interesting. I don’t own one, and have wondered if it would make me too focused on getting steps in but I’m glad to hear it didn’t have that effect for you. The calories is crazy! Like you, I assumed mine is much less than 100/mile but I wouldn’t have thought it was that few.

    1. I’ve found the slower I run, the more I burn per mile. Races I actually burn less which was so surprising!

  17. I find any tool that uses only heart rate to calculate calorie burn seriously underestimates it. I rarely look at my Garmin’s calorie burn, because my body has a way of telling me what I need to eat and I don’t gain or lose weight, but it says I burned close to 800 calories during a ten mile training run and that sounds about right in terms of how much I refueled. The FitBit does look cool, though, and it must be nice to have such easy access to your heart rate all day!

  18. I work from home so it definitely helps get me to move around but on run/workout days I know i’ll hit my 10K regardless. I love the sleep tracker. I’m almost obsessed with it! I’d rather know my sleep patterns than anything else. I used it once for a long run so I wouldn’t have to fuss with other contraptions and it was so woefully inaccurate on mileage that I simply don’t ever use it for that, which is irritating. Overall I really like it though.

  19. Sounds like a great tool for you. It’s always interesting to hear about why people buy them– lots of different reasons. I got mine as a gift and it doesn’t have the HRM, but like you, I care most about my HRM and sleep. The Sleep is really interesting, but I don’t know HR. That’s truly awesome that you walk so much at work. You’re lucky to have a job where you aren’t sitting all day long!

  20. I have the charge hr and have found with running the faster I am going the less accurate it is with the distance. I had a garmin vivofit and the bf gifted me this because I really wanted wrist HR. I love tracking hr data.
    I like the AMT for recovery/cross training as well and my hr barely gets to 110 but the machine is cranking out a calorie burn. I have known for a long time that is inaccurate but scares me to think some people do think it is!

  21. i recently switched from fitbit to jawbone for technical reasons but liked the sleep and heartrate tech the best. watching my sleep (more indepth with jawbone) really lead me to understand why i would be so tired the next day or things like that. thats really surprising about your calorie burn…seems a little off to me but i guess its all relative.

  22. I have the Garmin VivoActive, which has some of the same features as the FitBit, and agree with you on the step counter being off. One day I sat down to fold laundry, and turns out… it was logging my arms moving to fold laundry as steps. I think it’s a good way to be aware of your fitness activities like you mentioned, but it’s definitely not foolproof.

  23. I would love to see and analyze sleep data. I’m totally a high maintenance sleeper (at least eight hours per night to function), but I wonder what percentage of those hours is high quality/REM cycle or whatever it’s called.

  24. I liked my Fitbit when it worked. The sleep data was interesting but it always said I was awake whenever I would roll over. It’s not perfect but it was interesting.

  25. I have a fitbit flex that i brought back in January and I’m thinking about upgrading to the charge hr to have something to measure my heat rate. I was also surprised with the amount of steps I take a day more so since I thought I took a lot more then I actually do.

  26. I have both the Charge & the HR. The charge makes me feel more like a hero in that the numbers are slightly inflated over the HR. I am a creature of habit in that I do a lot of the same things the same way because of my commute and I find I track my progress by where I am. I love the Heart Rate feature though when I had my back problems last year and my resting heart rate skyrocketed, I switched back to the Charge so as not to be depressed. I do find it interesting to watch my resting HR climb during the week when I am in the office and then plummet by Sunday morning.

    1. That’s interesting. I haven’t tracked my heart rate by the week yet. I think I might do that next.

  27. Oooooh I’m fascinated with the sleep tracking and heart rate tracking! I’d love to know how my body ticks in those areas. Hmmmm…

  28. I don’t have a fitbit, but I have an apple watch, and I get so annoyed when it tells me to “move” after I’ve just done a hard workout or a run. NO, Apple Watch, the farthest I’m moving is to get some ice cream.

  29. thanks for sharing! i love having a fitbit for motivation, it definitely is a little off as far as steps but still gets you moving! its great how it tracks sleep patterns!

  30. I’ve had my FitBit for almost 2 years and I was obsessed with the step counter when I first got it. Now I mainly use it for checking the time and watching my sleep habits. I want to start working out more seriously so I’ll probably focus more on the calorie counts.

    1. It’s actually a really simple watch too. I was surprised, I like it for that feature as well!

  31. I have a Fitbit and I like it a lot to track hear rate and calorie burn. I agree it’s not 100% accurate but it gives a good idea of your activity for the day.

  32. I just got a jawbone U3 for my birthday (it looks more like a bracelet) and I have to agree
    1) doesnt pick up all the steps but I have it synced with my phone so it gets those
    2) so invested in my sleep and heart rate.

    for the past few weeks i have been holding myself accountable to get 10k steps now I want to even more.

  33. I love my fitbit. I find that it keeps me accountable for being active, especially when I’m doing a challenge with someone. I like the sleep and heart rate data too. I especially am interested in the heart rate data to see how well I recover. Someone above mentioned it taking them several weeks to recover from Dopey, its true – and it tracks it! I don’t know that the mileage ever claims to be very accurate. It doesn’t have a GPS in it (at least the Charge HR doesn’t – I think the Surge does), but I’ve found its close enough for government work 🙂

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