MyFitness Pal Calories Burned vs. Heart-Rate Calories Burned

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mdalton1987
mdalton1987 Posts: 4
in Health and Weight Loss
Hello,

I have read on here that My Fitness Pal isn't very accurate when taking into account the amount of calories burned during exercise (which I can see why), so I started calculating my heart rate. I wrote my heart rate down a few times throughout my workout, and then I took the average heart rate of that. I put it into a calculator I found online, and this calculator is telling me I am burning about 100 calories more than My Fitness Pal states (I am doing the insanity workout).

Which should I trust, or what should I put down in my exercise log?


Thanks for all the help I receive!!!

Replies

  • DericktheHutt
    DericktheHutt Posts: 4
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    MFP can't know how hard you actually worked so it takes what it considers an average. For example: two people riding their bikes. they are the same weight and height. They are going the same speed and in the same gear. BUT, one is in better cardiovascular shape. He is not working as hard as his friend to go that speed. His heart rate might only be 130 and his friend might be pushing 150. Calories burnt will be drastically different for the two. But like I said, MFP can't know this so it estimates based on what it thinks the average person will burn. How it decides what an average person is? I don't know.

    On the other hand, recording your HR a few times and averaging (Are you taking your pulse manually or do you have a simple HRM?) is that you might be taking it when more often at its peak ( or at its low) which will skew your average.

    I also made a horrible discovery about online calculators recently. Most of them are using a formula for women with a horrible typo in it. They have a "-" before the weight modifier when it should be a "+". So as you increase the weight of the woman, all else being equal, it reports them burning less calories! The men's is fine though. I was going to do a whole new topic discussing this when I found your post.

    The formulas are:
    Male: ((-55.0969 + (0.6309 x HR) + (0.1988 x W) + (0.2017 x A))/4.184) x T
    Female: ((-20.4022 + (0.4472 x HR) + (0.1263 x W) + (0.074 x A))/4.184) x T

    HR = Heart rate (in beats/minute)
    W = Weight (in kilograms) to convert pounds to kilograms divide by 2.2
    A = Age (in years)
    T = Exercise duration time (in minutes)

    The first three sites I found on Google had the error (stopped looking after that). The third site actually had the correct formula posted on the webpage, but used the erroneous one in their calculator. The one android app I found also had the error. I did find a Livestrong post with the correct formula, so all is not lost.

    Women will burn less calories as men at the same age, weight and HR. The gap will increase as HR and weight increase. I believe its because women (generally) have a higher max heart rate.
  • ohhman10
    ohhman10 Posts: 40
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    Get a heart rate monitor!

    I burn about 500-600 calories within an hour on my heart rate monitor... But if I plug that exact same thing into MFP it's like 200 less.

    HRM IS THE WAY TO GO! ;)
  • FionaAnne22
    FionaAnne22 Posts: 178 Member
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    I find generally mfp overestimates my calories burned substantially.. for example, this says for 30 minutes on the elliptical I'd burn over 400 but my hrm says it's only 160, quite a big difference! Moral of the story, get a hrm :)
  • sissiluv
    sissiluv Posts: 2,205 Member
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    I definitely go by heart rate. Even though I don't have a monitor, I can count my BPM by myself like a big girl, then I jump on a calculator site and plug it in to see how many cals I burned since I cannot math.

    The only pain is adjusting the time you spent exercising to match your cals burned via BPM in MFP.
  • mdalton1987
    mdalton1987 Posts: 4
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    Thank you everyone!!!
  • sskkg
    sskkg Posts: 7 Member
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    MFP can't know how hard you actually worked so it takes what it considers an average. For example: two people riding their bikes. they are the same weight and height. They are going the same speed and in the same gear. BUT, one is in better cardiovascular shape. He is not working as hard as his friend to go that speed. His heart rate might only be 130 and his friend might be pushing 150. Calories burnt will be drastically different for the two. But like I said, MFP can't know this so it estimates based on what it thinks the average person will burn. How it decides what an average person is? I don't know.

    On the other hand, recording your HR a few times and averaging (Are you taking your pulse manually or do you have a simple HRM?) is that you might be taking it when more often at its peak ( or at its low) which will skew your average.

    I also made a horrible discovery about online calculators recently. Most of them are using a formula for women with a horrible typo in it. They have a "-" before the weight modifier when it should be a "+". So as you increase the weight of the woman, all else being equal, it reports them burning less calories! The men's is fine though. I was going to do a whole new topic discussing this when I found your post.

    The formulas are:
    Male: ((-55.0969 + (0.6309 x HR) + (0.1988 x W) + (0.2017 x A))/4.184) x T
    Female: ((-20.4022 + (0.4472 x HR) + (0.1263 x W) + (0.074 x A))/4.184) x T

    HR = Heart rate (in beats/minute)
    W = Weight (in kilograms) to convert pounds to kilograms divide by 2.2
    A = Age (in years)
    T = Exercise duration time (in minutes)

    The first three sites I found on Google had the error (stopped looking after that). The third site actually had the correct formula posted on the webpage, but used the erroneous one in their calculator. The one android app I found also had the error. I did find a Livestrong post with the correct formula, so all is not lost.

    Women will burn less calories as men at the same age, weight and HR. The gap will increase as HR and weight increase. I believe its because women (generally) have a higher max heart rate.


    I found the same errors on the apps I downloaded for my iphone. But I finally found one that seems accurate. I think it's called calocalc by Jaz Games. It also matches the results I get when using the heart rate based calorie burn calculator I found on this website: http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

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