Fitbit estimate too high?

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miratps
miratps Posts: 141 Member
edited December 2016 in Fitness and Exercise
For background, I am male, 26 and weigh 125 lbs. I use Fitbit Blaze too

So I tend to exercise and walk A LOT, I'm talking hours in the day, been recently hitting 30k, 40k and even 50k steps on the regular (not that my legs are thanking me). But when I go for a dedicated walk I set it to exercise mode for walk and off I go no doubt with the usual buzzing that it lost connection to my phone for the millionth time.

Normally I always trusted the figure but because I never ate anywhere near the calorie number Fitbit gave me, I always kind of ignored the figure to a degree even though it's synced to my MFP - my intake goal was usually done on that. But now I want to maintain more healthily without doing a stupid amount of exercise on top of the walking. Problem is, I looked at my most recent walk which was 3 hours in duration and supposidly 9 miles (very leasurely I know, I just finished at the gym and previous days were hurting!) and it said I burnt over 1000 cals. Now this normally would make me think, fantastic but I typed my stats into another few websites, including MFP and Map My Run and they both say I would have only burnt half that.

Why is the FitBit overestimating so much? Am I missing something?
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Replies

  • Tacklewasher
    Tacklewasher Posts: 7,122 Member
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    Is it separating out the 3 hours of BMR from the exercise? That may account for some of the difference.

    3mph on the treadmill for me is ~150 cals for 25 mins. So that would be ~1,000 for 3 hours of walking, but I'm a lot heavier than you are (280) so I doubt it is right for you. I base my numbers off a chest strap I wear on the treadmill.
  • janicelo1971
    janicelo1971 Posts: 823 Member
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    Yes, i dont count it at all:( i just track and use it to motivate me to get 10 or 15,000 steps...whatever your goal is...sadly i dont think its accurate to do much else...but that is just me.
  • nutmegoreo
    nutmegoreo Posts: 15,532 Member
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    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?
  • janicelo1971
    janicelo1971 Posts: 823 Member
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    Great idea :)
    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

  • miratps
    miratps Posts: 141 Member
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    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

    Trying to maintain unsuccessfully. As I want to now do it mostly through diet like a 'normal' person, not go crazy with exercise. I know that sounds weird but I am not training for anything, nor do I want to, I just want to stay at a weight
  • nutmegoreo
    nutmegoreo Posts: 15,532 Member
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    miratps wrote: »
    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

    Trying to maintain unsuccessfully. As I want to now do it mostly through diet like a 'normal' person, not go crazy with exercise. I know that sounds weird but I am not training for anything, nor do I want to, I just want to stay at a weight

    You sound frustrated. How much are you eating each day, and what is happening with your weight?
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
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    miratps wrote: »

    Why is the FitBit overestimating so much? Am I missing something?

    As far as I'm aware, when you put fitbit HR devices in exercise mode they prioritise the HTML over the step counter for their calorie estimations. When HR is low then the accuracy of the relationship with calorie expenditure is very low. When you're walking so slowly then your HR would barely be registering above sedentary, so the calorie estimation will be significantly over.

    You should only be getting 350-400 cals for that walk.
  • miratps
    miratps Posts: 141 Member
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    miratps wrote: »

    Why is the FitBit overestimating so much? Am I missing something?

    As far as I'm aware, when you put fitbit HR devices in exercise mode they prioritise the HTML over the step counter for their calorie estimations. When HR is low then the accuracy of the relationship with calorie expenditure is very low. When you're walking so slowly then your HR would barely be registering above sedentary, so the calorie estimation will be significantly over.

    You should only be getting 350-400 cals for that walk.

    Thanks, but my walk was what, 3MPH or so? That number now feels low but safe than sorry. So should I not set it to exercise mode and just 'go' even if I do a run etc.?
  • miratps
    miratps Posts: 141 Member
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    nutmegoreo wrote: »
    miratps wrote: »
    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

    Trying to maintain unsuccessfully. As I want to now do it mostly through diet like a 'normal' person, not go crazy with exercise. I know that sounds weird but I am not training for anything, nor do I want to, I just want to stay at a weight

    You sound frustrated. How much are you eating each day, and what is happening with your weight?

    I am eating a lot more now, before I refused to go 1500 but now I am easily hitting over 2k and even throwing in finishing share size bags if sweets, although need to stop that soon.

    I am frustrated though, too much confusion about what I should or should not trust
  • nutmegoreo
    nutmegoreo Posts: 15,532 Member
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    miratps wrote: »
    nutmegoreo wrote: »
    miratps wrote: »
    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

    Trying to maintain unsuccessfully. As I want to now do it mostly through diet like a 'normal' person, not go crazy with exercise. I know that sounds weird but I am not training for anything, nor do I want to, I just want to stay at a weight

    You sound frustrated. How much are you eating each day, and what is happening with your weight?

    I am eating a lot more now, before I refused to go 1500 but now I am easily hitting over 2k and even throwing in finishing share size bags if sweets, although need to stop that soon.

    I am frustrated though, too much confusion about what I should or should not trust

    Trust your experiences, as far as calorie burns are concerned. It is hard to wrap your mind around some of this. If you are still losing at the 2000 (and with your activity levels, I would think that you likely are) then you can start scaling back the amount of walking you are doing. See how it goes.

    To be honest, I'm a little concerned that you feel like you have to restrict your calories so much and it almost sounds like you feel bad for eating a treat. You are a young guy, who is walking a lot. You should be able to eat quite well. As for the sweets, there is nothing wrong with fitting in a treat within an otherwise balanced diet. Now that you are eating more, it is easier for you to hit your nutritional needs. Once your nutrition is met, you get no bonus points for excess, so have a treat.

    How much weight did you lose? Over what period of time? I know these questions may seem unrelated, but they are very relevant in so far as your emotional approach to your weight loss. What are your goals? Are you wanting a particular physique?
  • miratps
    miratps Posts: 141 Member
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    nutmegoreo wrote: »
    miratps wrote: »
    nutmegoreo wrote: »
    miratps wrote: »
    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

    Trying to maintain unsuccessfully. As I want to now do it mostly through diet like a 'normal' person, not go crazy with exercise. I know that sounds weird but I am not training for anything, nor do I want to, I just want to stay at a weight

    You sound frustrated. How much are you eating each day, and what is happening with your weight?

    I am eating a lot more now, before I refused to go 1500 but now I am easily hitting over 2k and even throwing in finishing share size bags if sweets, although need to stop that soon.

    I am frustrated though, too much confusion about what I should or should not trust

    Trust your experiences, as far as calorie burns are concerned. It is hard to wrap your mind around some of this. If you are still losing at the 2000 (and with your activity levels, I would think that you likely are) then you can start scaling back the amount of walking you are doing. See how it goes.

    To be honest, I'm a little concerned that you feel like you have to restrict your calories so much and it almost sounds like you feel bad for eating a treat. You are a young guy, who is walking a lot. You should be able to eat quite well. As for the sweets, there is nothing wrong with fitting in a treat within an otherwise balanced diet. Now that you are eating more, it is easier for you to hit your nutritional needs. Once your nutrition is met, you get no bonus points for excess, so have a treat.

    How much weight did you lose? Over what period of time? I know these questions may seem unrelated, but they are very relevant in so far as your emotional approach to your weight loss. What are your goals? Are you wanting a particular physique?

    I lost over 35kg since March. My goal now is just to maintain the weight, no real fitness goals. In terms of physique, just a slim face and body but I know when I wake up each morning I look like I've added a whole load of weight so get paranoid and think I need to exercise like crazy again
  • nutmegoreo
    nutmegoreo Posts: 15,532 Member
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    miratps wrote: »
    nutmegoreo wrote: »
    miratps wrote: »
    nutmegoreo wrote: »
    miratps wrote: »
    nutmegoreo wrote: »
    I find my FitBit tends to ender estimate by about 200 calories per day. Trial and error is the best way to know for sure. Experiment with eating a portion of it back, see what happens, and adjust accordingly. They are computers and cannot possibly be 100% accurate for everyone. At 125 lbs are you trying to gain/maintain?

    Trying to maintain unsuccessfully. As I want to now do it mostly through diet like a 'normal' person, not go crazy with exercise. I know that sounds weird but I am not training for anything, nor do I want to, I just want to stay at a weight

    You sound frustrated. How much are you eating each day, and what is happening with your weight?

    I am eating a lot more now, before I refused to go 1500 but now I am easily hitting over 2k and even throwing in finishing share size bags if sweets, although need to stop that soon.

    I am frustrated though, too much confusion about what I should or should not trust

    Trust your experiences, as far as calorie burns are concerned. It is hard to wrap your mind around some of this. If you are still losing at the 2000 (and with your activity levels, I would think that you likely are) then you can start scaling back the amount of walking you are doing. See how it goes.

    To be honest, I'm a little concerned that you feel like you have to restrict your calories so much and it almost sounds like you feel bad for eating a treat. You are a young guy, who is walking a lot. You should be able to eat quite well. As for the sweets, there is nothing wrong with fitting in a treat within an otherwise balanced diet. Now that you are eating more, it is easier for you to hit your nutritional needs. Once your nutrition is met, you get no bonus points for excess, so have a treat.

    How much weight did you lose? Over what period of time? I know these questions may seem unrelated, but they are very relevant in so far as your emotional approach to your weight loss. What are your goals? Are you wanting a particular physique?

    I lost over 35kg since March. My goal now is just to maintain the weight, no real fitness goals. In terms of physique, just a slim face and body but I know when I wake up each morning I look like I've added a whole load of weight so get paranoid and think I need to exercise like crazy again

    That's a fair amount of weight, and at a pretty fast rate. Sounds more like your brain hasn't caught up with the changes in your body. That could take some time yet. In the meantime trust the numbers on your scale and fitbit. If these thoughts are pervasive (sounds like they might be), it would be worth considering seeing a professional (counselor) to help you during this time. I realize you might scoff at that suggestion, but it is worth thinking about. Particularly because you seem to be a bit overwhelmed by this right now. Congratulations on reaching your weight goal. I wish you all the best in making it sustainable and finding a way to not drive yourself nuts in doing so.
  • Christine_72
    Christine_72 Posts: 16,049 Member
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    miratps wrote: »

    Why is the FitBit overestimating so much? Am I missing something?

    As far as I'm aware, when you put fitbit HR devices in exercise mode they prioritise the HTML over the step counter for their calorie estimations. When HR is low then the accuracy of the relationship with calorie expenditure is very low. When you're walking so slowly then your HR would barely be registering above sedentary, so the calorie estimation will be significantly over.

    You should only be getting 350-400 cals for that walk.

    Wouldnt the calorie burn be significantly under if his HR is barely registering above sedentary?
  • Gallowmere1984
    Gallowmere1984 Posts: 6,626 Member
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    I had to set my Blaze to think I am a 5'2" 85 year old man (really 5'10" and 32) in order to get it to stop giving me stupid high burns that resulted in my gaining 2 lbs./ week, when it was set to lose 1. Fortunately, I was in a bulking phase anyway, and was more testing it's accuracy.
  • Cylphin60
    Cylphin60 Posts: 863 Member
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    I went with a lower end fitbit (charge 2) precisely because of all the confusion I've seen over calorie burn. My solution so far is keeping it really simple. I use mfp to track calories and the fitbit for steps/HR/sleep.

    I add my time for any given exercise accurately in mfp, but I'm restricting (mostly) myself to eating back only 50% or less of the calories burned.

    I haven't had the fitbit for long, but as long as I keep it simple we'll do good together. No mental gymnastics for me lol. If I start to gain weight, then I'll just double check my logging accuracy and probably cut back a bit if required, because occasionally the extra slice of pizza just kind of crawls onto my plate.
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
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    miratps wrote: »

    Why is the FitBit overestimating so much? Am I missing something?

    As far as I'm aware, when you put fitbit HR devices in exercise mode they prioritise the HTML over the step counter for their calorie estimations. When HR is low then the accuracy of the relationship with calorie expenditure is very low. When you're walking so slowly then your HR would barely be registering above sedentary, so the calorie estimation will be significantly over.

    You should only be getting 350-400 cals for that walk.

    Wouldnt the calorie burn be significantly under if his HR is barely registering above sedentary?

    No, the algorithms significantly overestimate if they're too low, below the cardiac threshold, and too high, above the lactate threshold. Essentially they overcompensate for the proportion of HR elevation as a result of low intensity exercise as it's difficult to determine what's a result of the activity and what's not.
  • Christine_72
    Christine_72 Posts: 16,049 Member
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    miratps wrote: »

    Why is the FitBit overestimating so much? Am I missing something?

    As far as I'm aware, when you put fitbit HR devices in exercise mode they prioritise the HTML over the step counter for their calorie estimations. When HR is low then the accuracy of the relationship with calorie expenditure is very low. When you're walking so slowly then your HR would barely be registering above sedentary, so the calorie estimation will be significantly over.

    You should only be getting 350-400 cals for that walk.

    Wouldnt the calorie burn be significantly under if his HR is barely registering above sedentary?

    No, the algorithms significantly overestimate if they're too low, below the cardiac threshold, and too high, above the lactate threshold. Essentially they overcompensate for the proportion of HR elevation as a result of low intensity exercise as it's difficult to determine what's a result of the activity and what's not.

    Ah ok :smile: I've always stayed away from HR monitor devices, I have the fitbit Alta. But lately I've been thinking about upgrading to the charge 2, and whenever i get close to making a firm decision a post such as your pops up lol My only exercise is walking, and i doubt my heart rate rises a lot, so once again I'm thinking a HR monitor device would be a waste of time and especially $$$ for me. The Charge 2 is $269 here.
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
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    Ah ok :smile: I've always stayed away from HR monitor devices, I have the fitbit Alta. But lately I've been thinking about upgrading to the charge 2, and whenever i get close to making a firm decision a post such as your pops up lol My only exercise is walking, and i doubt my heart rate rises a lot, so once again I'm thinking a HR monitor device would be a waste of time and especially $$$ for me. The Charge 2 is $269 here.

    I have a Garmin VivoSmart HR, which Garmin gave me as a replacement for a VivoSmart. I don't think I'd have gone for it otherwise. The main useful data point is my Resting Heart Rate, but it can also broadcast on ANT+ to my Forerunner, Edge and Virb devices, so it can avoid faffing about with a chest strap.

    Personally I don't think most people benefit from HR data collection.

  • ChelzFit
    ChelzFit Posts: 292 Member
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    I have the Charge HR2 and I have noticed that if I don't set mine in exercise mode it overestimates a ton. For the last few days I have just done 40 minute walks completing a total of 2 miles. Looking at my Fitbit I noticed it stated that during my walk my heart rate maxed to 168 and I burned 498 calories. That is way off! For my weight/height I burned only around 200 cals if less. It will even note that I did the elliptical. Now on my workout days when I actually set my HR to a run or workout I notice that the calorie burn is the same as my Polar Heart Rate watch. I didn't have these issues with my original charge so I don't know why it is overestimating with just walking.
  • ForecasterJason
    ForecasterJason Posts: 2,577 Member
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    I'm about the same size and have a Fitbit One. It seems to me that the more exercise I do, the more it overestimates calories burned. I have determined this to be a result of it overestimating the METs when I'm exercising, as it'll often label my activity as "intense" when it's really more like moderate intensity.