Fitbit and calories burned

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keziak1
keziak1 Posts: 204 Member
in Health and Weight Loss
Anyone use Fitbit? I think the number of calories they claims are burned by exercise have to be off, perhaps really off. Does anyone know if this is the case?

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  • jessicapk
    jessicapk Posts: 574 Member
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    I've been tracking my Fitbit calories burned and comparing to my calories I eat each day. I use a spreadsheet that calculates my deficit and theoretical loss based on that deficit. I certainly don't think the Fitbit is overestimating. If anything, it's underestimating my calorie burn. My real weight loss is currently twice as much as my theoretical weight loss, which says I'm either burning more or eating less. I weigh everything I eat so I tend to lean towards burning more. Of course, walking is one of my main forms of exercise, so that could play a huge part in it since the Fitbit focuses on steps.
  • Lib_B
    Lib_B Posts: 446 Member
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    I don't trust it because unless you have the one that measures heart rate, it's just estimating. If you need to know exercise calories burned, I'd recommend an HRM. I mostly use my FitBit for tracking steps and sleep. I've noticed the amount of sleep I get impacts the number of calories and quality of food I eat the next day - with more sleep equating to better choices. I would trust their calculations as an estimation, but I would never eat back exercise calories earned on my FitBit...
  • 4legsRbetterthan2
    4legsRbetterthan2 Posts: 19,590 MFP Moderator
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    keziak1 wrote: »
    Anyone use Fitbit? I think the number of calories they claims are burned by exercise have to be off, perhaps really off. Does anyone know if this is the case?

    Why do you think this?

    Mine seems to be pretty accurate unless its super windy (fitbit one) which screws with the "stair climbed" calculation.

  • ElleMuffin
    ElleMuffin Posts: 7 Member
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    I agree with PP. Last year I lost almost 50 pounds in 6 months using my fitbitflex + myfitnesspal. I generally lost more than what both estimated as long as I weighed/measured my food and logged accurately and diligently. I think sometimes we measure/estimate poorly and derail our weightless by unconsciously over eating. If you're not seeing results, I'd check measurements 1st, then play around with your carb/fat/protein ratios. I lost fastest at 40/30/30, but I think it depends on the individual. Good luck!
  • jessicapk
    jessicapk Posts: 574 Member
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    Oddly enough, the Fitbit Flex is considered one of the more accurate calorie counters out there, with the Garmin Vivofit coming out first from my research. I've seen a few reviews with bad words for the Charge HR (and I was so excited when it came out!) and decided against it. The Flex is serving me very well so far.
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    edited March 2015
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    Seems to be right or underestimate for me. Judged by the fact that now I'm in maintenance and if I eat at or under what Fitbit shows for me - I continue to lose weight.

    Fitbit is using similar formulas to MFP and other sites to estimate calories burned. Keep in mind it is not JUST giving you calories burned for exercise, but also factoring in the calories you burn for living. Based on height, weight, etc... Though no tracker is going to be 100% accurate, it should not be too far off. Even without a HRM.

    I know when Fitbit is likely to be off for me. For example if I'm walking on the treadmill at 3.5 mph with a 5% incline, it will give me the same burn value as if I'm walking 3.5 mph on the treadmill no incline. When in reality, the incline burns more. And if I'm running in place (more steps per minute) I know from using a HRM that the burn is similar to a brisk walk. So there Fitbit overestimates.

    They're great devices for someone who uses it to motivate themself to move more. Not a magic tool for weight loss - the motivation is a necessity.

  • keziak1
    keziak1 Posts: 204 Member
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    well this is good news then. It's important to remember that they are also giving the calories burned just by living. I was suspicious since it looks like they claim more calories burned in my workouts than I expected.

    I love my Fitbit and how it gets me moving all the time so I get 10K-12K steps a day. The weight is coming off nicely!
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
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    If you have a compatible smart phone you can open the app while you're working out - and pay attention to how many calories are being burned per minute. Just watch how it changes. Might give you a better idea. For me when I'm walking a brisk pace its generally 5 per minute. Running is 6-7. That includes my BMR which is just shy of 1 calorie per minute, so walking is actually burning an extra 4, or an extra 5-6 for running.
  • Angierae75
    Angierae75 Posts: 417 Member
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    When I am consistently tracking my food, I eat back most of what my Fitbit gives me. I lost 22 pounds in 21 weeks. (I've been off the wagon for the last month, getting back on track now.)

    I've found it to be perfectly accurate for my needs.
  • Abby2205
    Abby2205 Posts: 253 Member
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    Mine (One) seems very accurate, but my only activity is walking. I analyzed my data over 14 weeks (calories burned per Fitbit and calories consumed per logging), and the total deficit was very close to actual weight loss in that period, within 2% of theoretical 3500 calories= 1 pound. It was so close that I actually considered whether I had unconsciously biased my logging to agree with the observed weight loss trend and Fitbit trend over the period. Either I am the theoretical average person, or errors in logging and Fitbit calories burned are both in the same direction. I'm happy with either.
  • lzepeda89
    lzepeda89 Posts: 33 Member
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    I think my FitBit Charge is pretty accurate when it comes to running and walking. However, I know when I do activities like Zumba and UJam it severely underestimates my calories burned. But honestly that doesn't really bother me because unless I've still been able to lose weight, also it's kinda like a crutch in case I ever go over my calorie intake.
  • JenniferInCt
    JenniferInCt Posts: 431 Member
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    StaciMarie1974 wrote: »

    I know when Fitbit is likely to be off for me. For example if I'm walking on the treadmill at 3.5 mph with a 5% incline, it will give me the same burn value as if I'm walking 3.5 mph on the treadmill no incline. When in reality, the incline burns more. And if I'm running in place (more steps per minute) I know from using a HRM that the burn is similar to a brisk walk.

    Based on the treadmills calorie burn estimate (which i know can be overestimated), my fitbit is almost the exact same burn. If off, by no more than 5cals. Even when on an incline. But the treadmill does allow me to put my weight in, so maybe thats why. The only place I've noticed my charge hr didnt seem as accurate was the distance, but that's because I haven't measured my stride length yet.
    I love my charge hr. But i also do not wat back all the calories, as i think ive found a sweet spot to stay in for now. When i first got the fitbit, it threw me off a little to have it change my mfp calories so much. I shut off negative adjustments and eat back no more than 1/2.
  • LovingLife_Erin
    LovingLife_Erin Posts: 328 Member
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    I have a flex, and I'm assuming it is pretty accurate for me as whenever I do the maths of my calories in/out, I'm usually within .5 lb of what I actually lost for the week. I've had it for a few months now so I've learned to trust it.

    For some of my workouts though, the calories calculated are actually too low compared to every other site, by a significant margin (ie: it will say I've burned 300 for an hour of aquafit but numerous other sites will have me at burning about 500. I usually split the difference and will go for around a 400 burn). Otherwise, most things are pretty accurate for me, and as I said, I typically lose what I should based on what it says I'm burning and MFP says I'm eating.
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
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    When I was losing I went with the assumption that nothing can be 100% accurate so I would typically leave calories 'on the table'. Not a massive # but something like 100-200. So instead of a 500 deficit, my Fitbit showed a 600-700 deficit.

    My treadmill does not allow user info - so it gives the calorie burn for an imaginary person with unknown stats. I wish I burned as many calories as he does. (They're high so I'm assuming its a guy.)

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