accuracy of fitbit exercise calories

jasveersingh925
jasveersingh925 Posts: 50 Member
in Health and Weight Loss
hey all,

I use a fitbit like many other people here to track how many calories I am burning a day. I like how it sync's up with MFP to let you know how many calories you've burned. I think that tracking how many steps you take provides a fairly good estimate of how much you're burning, whether it is through activity or intentional exercise. Also, I have been pretty happy with the adjustments being made to MFP day to day. It has provided amount of exercise calories to my weekly budget. In your experience, how accurate has the fitbit been for you as far as weight loss and eating these back? I only do running and walking and aim to increase my step count.

Thanks

Replies

  • Holly_Roman_Empire
    Holly_Roman_Empire Posts: 4,440 Member
    hey all,

    I use a fitbit like many other people here to track how many calories I am burning a day. I like how it sync's up with MFP to let you know how many calories you've burned. I think that tracking how many steps you take provides a fairly good estimate of how much you're burning, whether it is through activity or intentional exercise. Also, I have been pretty happy with the adjustments being made to MFP day to day. It has provided amount of exercise calories to my weekly budget. In your experience, how accurate has the fitbit been for you as far as weight loss and eating these back? I only do running and walking and aim to increase my step count.

    Thanks

    If running and walking are all your exercise, don't eat all the calories fitbit gives you. You're basically eating your TDEE, and you're only going to maintain at that rate.
  • jasveersingh925
    jasveersingh925 Posts: 50 Member
    Since MFP already has me at a 1 lb loss per week, it keeps that rate for me when Fitbit syncs up. I only consider the calorie adjustment on MFP based on my work recorded on the Fitbit, not reading from the maintenance amount the Fitbit has.

    Given this, how accurate has the device been for estimating caloric burn from the associated activity? Thanks for your help!
  • RHachicho
    RHachicho Posts: 1,115 Member
    Fitbit's accuracy is not that great. I've seen it give me bad figures quite a bit. I don't think anyone should really depend on it's calorie adjustments too much. It's probably ok if all you do is walking. For example it will give significantly more calories for a 1.5 hour walk than a 1 hour run. I think all it really does takes into account is how long you exercise and how many steps you do in that time. It's not very good at factoring in any level of intensity.
  • daveymac31
    daveymac31 Posts: 118
    It's just a pedometer.
  • TheStephil
    TheStephil Posts: 858 Member
    I have found Fitbit to be pretty accurate. I dont connect it to MFP because I don't like how it guesses your "calorie adjustments" based off how much exercise you have done so far and assumes you will continue that activity the rest of the day so the calorie adjustment is higher in the morning for me than it will be at the end of the day and I end up overeating. I've used MFP and Fitbit long enough to know what my normal calories burned is so I just set my calorie goal on MFP to reflect that.
  • TheStephil
    TheStephil Posts: 858 Member
    Fitbit's accuracy is not that great. I've seen it give me bad figures quite a bit. I don't think anyone should really depend on it's calorie adjustments too much. It's probably ok if all you do is walking. For example it will give significantly more calories for a 1.5 hour walk than a 1 hour run. I think all it really does takes into account is how long you exercise and how many steps you do in that time. It's not very good at factoring in any level of intensity.

    I have to disagree, it gives you more calories for "very active minutes" than active or moderate minutes. If you are walking then you are most likely doing moderate or sometimes active minutes but if you are running then you are doing very active minutes.

    An average person burns 100 calories for 1 mile. It doesn't matter if you run, walk, stroll, etc. that mile. If you are running, you will do more miles in the same amount of time as you would walking so you would burn more calories in that time.

    To get into more detail, Fitbit is extremely accurate for me. I decided to eat at maintenance for a month and ate as many calories as Fitbit told me I burned. I weighed all my food, did not go out to eat and prepared all my meals myself so I knew the calories. I stayed the exact same weight during that month. This was before I was doing strength training and was only walking and running so that may contribute.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Since MFP already has me at a 1 lb loss per week, it keeps that rate for me when Fitbit syncs up. I only consider the calorie adjustment on MFP based on my work recorded on the Fitbit, not reading from the maintenance amount the Fitbit has.

    Given this, how accurate has the device been for estimating caloric burn from the associated activity? Thanks for your help!
    You are using it correctly. (Which is half the battle. :laugh: )

    I lost 35 lbs. with it in 2010. My deficit implied I'd lose around 35 lbs. So it was either really accurate for me or its error was equal and opposite my food logging error. :smile: I've lost 15+ this year. I think my deficit and my weekly loss rate imply it's still accurate for me, but I haven't done the math lately to check.
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    I think its pretty accurate for me. Though I do try to leave an extra 100-200 calories 'extra' to account for estimation errors. My goal deficit is 250. Generally I eat 1600-1800, and Fitbit shows me burning a total of 2000-2100.
  • jasveersingh925
    jasveersingh925 Posts: 50 Member
    Fitbit's accuracy is not that great. I've seen it give me bad figures quite a bit. I don't think anyone should really depend on it's calorie adjustments too much. It's probably ok if all you do is walking. For example it will give significantly more calories for a 1.5 hour walk than a 1 hour run. I think all it really does takes into account is how long you exercise and how many steps you do in that time. It's not very good at factoring in any level of intensity.

    I have to disagree, it gives you more calories for "very active minutes" than active or moderate minutes. If you are walking then you are most likely doing moderate or sometimes active minutes but if you are running then you are doing very active minutes.

    An average person burns 100 calories for 1 mile. It doesn't matter if you run, walk, stroll, etc. that mile. If you are running, you will do more miles in the same amount of time as you would walking so you would burn more calories in that time.

    To get into more detail, Fitbit is extremely accurate for me. I decided to eat at maintenance for a month and ate as many calories as Fitbit told me I burned. I weighed all my food, did not go out to eat and prepared all my meals myself so I knew the calories. I stayed the exact same weight during that month. This was before I was doing strength training and was only walking and running so that may contribute.

    I agree with you. You will certainly burn more calories running in the same amount of time spent walking, but that doesn't spell inaccuracy. If anything, it is a good thing because the device is underestimating your caloric burn if it is not giving full credit for running 1 hour vs. walking 1 and a half hours. But I don't think it does that; it has been pretty consistent for me.
  • Followingsea
    Followingsea Posts: 407 Member
    I have found Fitbit + MFP to be incredibly on point for me.
  • csuhar
    csuhar Posts: 779 Member
    It's generally been accurate enough for my purposes. But I will say I don't even bother to try and use it for anything other than measuring walking/running related expenditures. I will often log those exercise calories at a time when I know the fitbit isn't recording to keep my weight-lifting work and my foot work calories separate and avoid double-dipping.
  • malibu927
    malibu927 Posts: 17,562 Member
    hey all,

    I use a fitbit like many other people here to track how many calories I am burning a day. I like how it sync's up with MFP to let you know how many calories you've burned. I think that tracking how many steps you take provides a fairly good estimate of how much you're burning, whether it is through activity or intentional exercise. Also, I have been pretty happy with the adjustments being made to MFP day to day. It has provided amount of exercise calories to my weekly budget. In your experience, how accurate has the fitbit been for you as far as weight loss and eating these back? I only do running and walking and aim to increase my step count.

    Thanks

    If running and walking are all your exercise, don't eat all the calories fitbit gives you. You're basically eating your TDEE, and you're only going to maintain at that rate.

    If you set Fitbit accurately (i.e. to the same deficit/activity level as MFP) it will give you a similar amount of calories.

    OP, my Fitbit is pretty accurate as well. I use it mainly to judge how active I am at work (in retail) and see if I need to make an adjustment to my food log or walk a bit more after I get home. Sometimes I eat all the calories back, sometimes I don't.
  • jasveersingh925
    jasveersingh925 Posts: 50 Member
    If you set Fitbit accurately (i.e. to the same deficit/activity level as MFP) it will give you a similar amount of calories.

    OP, my Fitbit is pretty accurate as well. I use it mainly to judge how active I am at work (in retail) and see if I need to make an adjustment to my food log or walk a bit more after I get home. Sometimes I eat all the calories back, sometimes I don't.

    Yes, I have been not eating the calories back and saving them in case I have meals I can't count accurately once in a while.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    ...it will give significantly more calories for a 1.5 hour walk than a 1 hour run. I think all it really does takes into account is how long you exercise and how many steps you do in that time. It's not very good at factoring in any level of intensity.
    Mine gives way more calories per minute for running. It uses a tri-axis accelerometer to know how much you're moving in three planes and how much impact you're generating. Your steps count isn't even used as part of your calorie estimate. That's based entirely on your BMR and the METs value of the activity it senses you're doing.

    If you're on a bike or under resistance, forget it-- it doesn't detect that.
  • RHachicho
    RHachicho Posts: 1,115 Member
    well i dunno i do a 1 hour walk and get a 600 cal adjustment and then the next day I do a 5km run and get a 333 calorie adjustment. these where done early in the day. Maybe it's just the flex that isn't that accurate. Or maybe I hit mine on something ... who knows.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    It's hard to judge workout calories from the Fitbit adjustment because the adjustment takes all your activity across the day into account. The day of the walk, were you just up and about a lot more than the other day? If you go to the Fitbit site you can view your walk and run separately and see how many calories each burned.

    Though they admit the Flex is less accurate than the torso-worn models, overall.
  • satisfyingmyinnerfatkid
    satisfyingmyinnerfatkid Posts: 43 Member
    After buying Fitbit Flex and then a Fit Bit Zip I have determined that Fit Bit sucks! lol Fitbit is a gloried pedometer. If you want a accurate calorie counting device: BodyMedia. It is equipt with skin sensors that are pretty darn accurate. I burn anywhere from 2000 to 2600 calories a day (daily life and intentional exercise together). Only problem is the also stupidly inaccurate calorie counting device which is also ONLY a glorfied pedometer called Jawbone UP bought out Bodymedia so that it could kill competition.

    The thing is... if you are well into the obese category (I'm talking like morbidly obese .. me at 5 ft. 3 and 258 pounds) chances are you are not an active person and walking either hurts or is boring and running.. forget about it lol

    You need something exciting to convince you exercise or movement in general is fun and worth it like Just Dance, a bike ride, swimming. All stuff Fitbit cannot accurately track.

    All you'll wind up doing is being depressed that your already active skinny friends who wear Fitbit get 10,000 steps a day meanwhile you got 5,000 to 8,000 steps a day not by being lazy (because that produces only 1,000 to 3,000 steps) but by working your butt off doing fun workouts Fitbit cannot count.

    YEAH lol
  • redwoodkestrel
    redwoodkestrel Posts: 339 Member
    I find my Fitbit to be accurate enough - certainly more accurate than MFP's calorie adjustments. As long as most of your exercise is through step-based activities, the Fitbit should work out fine. It:
    - knows your age, height, and weight
    - knows the activity level you're set at, and gives you calories based on that (or takes away calories if you're not living up to your activity level!)
    - knows your stride length (one you input it)
    - knows how many steps you take AND how fast you took them - so it DOES take intensity into account
    - knows when during your workout you sped up or slowed down, making it more accurate than the average that MFP gives you

    Plus I love all the charts and graphs and whatnot that Fitbit gives you. I've lost ~75 lbs since January with my Fitbit and counting calories on MFP, so it works GREAT with me. I also find it's good motivation - I ALWAYS get my 10K steps in, usually 20K.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    Jawbone UP bought out Bodymedia so that it could kill competition.
    Maybe Jawbone bought Body Media because they thought it was a desirable niche, how Body Media stuck some skin sensors on an accelerometer and people thought it did something valuable enough to pay a monthly fee for.
  • mlh37214
    mlh37214 Posts: 517 Member
    Going to admit that I have only glanced at other responses: My experience: when I was consistent with recording my calories and working out, my Fitbit seemed to be pretty accurate - I almost alway ate the calories it gave me for my exercise and still lost. With that said, I would make sure that you've put in your height/weight/measurements to make it as accurate as possible. Also, I was sure to log my workout times accurately b/c it would then change the fitbit adjustment (lower) and add workout calories. So maybe, it wasn't the fitbit that was so accurate, but more my logging. I never really compared what the Fitbit gives me vs what MFP gives me with logging. Just getting back on the wagon and may need to check that out. Food for thought.
  • jasveersingh925
    jasveersingh925 Posts: 50 Member
    Many great responses here, much appreciated. I've tried the Fitbit with activities besides running and walking... more recently, jumping rope. I find that it counts the steps that I am jumping but since the activity is so taxing and intense compared to walking, you can only bet that it is underestimating calories burned (the same might be the case for running as well). I think that its usefulness is partly due to the fact that counting calories burned is not an exact science, plus if the device is ALWAYS underestimating and you are going by that, you can't really go wrong.
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    Anything you use is simply going to be an estimate...if it were me, I'd spend some time and compare the burns my device was giving me to other sources and estimate conservatively. That's pretty much what I used to do with my HRM...eventually I figured out that if I knocked off around 20% or so of what my HRM said, I had a relatively accurate, but conservative number.

    I also used factors of 5-10...with 5 calories per minute being basically a walk in the park and 10 calories per minute being an all out, bust my *kitten*, can't talk or think or do anything but focus on my workout kind of intensity level. Most cardiovascular workouts for me are around an 8.

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