Discrepency between HRM and mfp calories burned. WHY SO BIG?

Smurfette1987
Smurfette1987 Posts: 110 Member
in Fitness and Exercise
Hi :)

I can understand the calorie burn calculators on here being different to what you actually burn, it's an estimate after all. But (and forgive me if I'm the 10,000000th person to make this thread) how can they be SOOOO FARRR off my HRM?
For example if I do an hour of Taekwon-do and use my HRM I burn around 300 cals GROSS, ( I haven't saved up for a net cals HRM YET:) and that figure is excluding a 20 minute warm up that I wouldn't log. That's HIIT bag work and shadow sparring etc, so I'm working pretty hard and often going above 90% MHR (not ideal I know). Now I am a midget (hence my username) but 300 cals seemed pretty disheartening when I first got my HRM, as MFP tells me I burn 700 or so!
Now that I've had the monitor for a while I've seen how far off MFP is in every activity and I just accept that I burn much less. I still find it confusing, is everyones numbers so far off? If so, why?

Replies

  • sushiadct
    sushiadct Posts: 4
    HRM is the most accurate.... your size and mass has a lot to do with how many calories you intake as well as how much you burn. MFP is just a guess...... my wife works out just as hard as me sometimes.... but burns half the calories because of her mass... Don't think too much into it.. but if you have a HRM with a strap.. go with those figures... it's not going to get get more accurate then that.
  • sushiadct
    sushiadct Posts: 4
    I forgot to mention the intensity is huge as well.
  • FionaAnne22
    FionaAnne22 Posts: 178 Member
    I just posted pretty much this exact thread, there is a really big difference in my burn too...hundreds! No idea why mfp's estimates are so high! Also, I'm 215 pounds so I'm really confused as to how I'm burning so *"little" in comparison to what I thought I was!
  • KenSmith108
    KenSmith108 Posts: 1,967 Member
    I just posted pretty much this exact thread, there is a really big difference in my burn too...hundreds! No idea why mfp's estimates are so high! Also, I'm 215 pounds so I'm really confused as to how I'm burning so *"little" in comparison to what I thought I was!
    Funny, I find MFP hundreds low compaired to my HRM, but fairly close to the treadmill's #s if I have the incline up a little.
  • eksproductions
    eksproductions Posts: 138 Member
    Easy answer is to go with your HRM, for me the numbers here have just been placeholders. I add in the correct amount when I wear my HRM, and when I don't, I don't worry about it. As long as I am working out daily I'm happy, and the numbers turn out not to be as important as doing the physical activity itself.
  • JoAnn73
    JoAnn73 Posts: 161 Member
    HRM are the best and most accurate. APPs LIKE Endomando, MFP and other over est by at least 20%. Since i've purchased my HRM i would compare and its always over est. Invest in a HRM if possible.
  • kikicooks
    kikicooks Posts: 1,079 Member
    MFP is a general estimate. Every body is so different with so many factors to consider so there is no way it could know each individual's calorie burn.
  • DocMarr
    DocMarr Posts: 132 Member
    Fiona, have you made sure that you've set your HRM with your correct weight, height etc? That makes a difference. I seem to find that my HRM always gives me a bigger burn than MFP or my Fitbit would for exercising. I've often wondered if it's because I have a large 'heart rate reserve', which means my heart beat has a wide range from 48 resting to 181 peak during workout (and I can still breath quite easily even at 181). Another friend I have says even when she's working flat out she never gets above 165. I wondered if people have a smaller heart range then perhaps their burn is smaller? Maybe someone who knows more about it can enlighten us :)
  • samblanken
    samblanken Posts: 369 Member
    I find that MFP overestimates burn quite a bit. If I work on the treadmill and the machine says I burned 300 cals, when I go to enter my time and pace into MFP it will come up with something almost double. Hence why I am reluctant to eat back exercise calories.
  • enzamatic
    enzamatic Posts: 12 Member
    Just curious, I too don't want to "eat back" exercise calories because I more consider them bonus. So...do you just ignore the "calories left" for the day and just try to make your goal calories match your consumed? I was surprised, having used "DailyBurn" in the past, that there wasn't an option to exclude exercise calories from the goal calories. I'm just going to eyeball it the way I described above.
  • agthorn
    agthorn Posts: 1,844 Member
    Fiona, have you made sure that you've set your HRM with your correct weight, height etc? That makes a difference. I seem to find that my HRM always gives me a bigger burn than MFP or my Fitbit would for exercising. I've often wondered if it's because I have a large 'heart rate reserve', which means my heart beat has a wide range from 48 resting to 181 peak during workout (and I can still breath quite easily even at 181). Another friend I have says even when she's working flat out she never gets above 165. I wondered if people have a smaller heart range then perhaps their burn is smaller? Maybe someone who knows more about it can enlighten us :)
    The '220-age' for maximum HR is just a general average for the population; an individual can have a maxHR that is up to 30 beats higher or lower than their predicted value. So doing a maxHR test on a treadmill, while it sucks, provides valuable information. Also, a good HRM should account for vO2max, or your aerobic fitness. If Lance Armstrong and I are riding bikes at the same speed, his HR is going to be lower than mine even though we're doing the same amount of work. Many Polar HRMs will use this number to adjust your calorie burn.

    And if your HRM doesn't have a chest strap, don't bother - it's not going to provide any more accurate information than the website estimates.
  • agthorn
    agthorn Posts: 1,844 Member
    Just curious, I too don't want to "eat back" exercise calories because I more consider them bonus. So...do you just ignore the "calories left" for the day and just try to make your goal calories match your consumed? I was surprised, having used "DailyBurn" in the past, that there wasn't an option to exclude exercise calories from the goal calories. I'm just going to eyeball it the way I described above.
    If you don't want to use the base+exercise method, then set your calories to maintenance and let your exercise create your deficit. But this only works if you are consistent with your exercise.
  • Dave198lbs
    Dave198lbs Posts: 8,810 Member
    I've seen how far off MFP is in every activity and I just accept that I burn much less. I still find it confusing, is everyones numbers so far off? If so, why?

    It's a conspiracy. MFP gives you a high number for calories burned then tells you to eat them or else you go into starvation mode.

    So you eat all false those exercise calories and cannot lose weight. This makes you stay here longer and see all the ads that many more times.

    It's genius. They are winning. How many posts do you see that say..."I'm doing everything right and still can't lose weight"?
  • SheilaBradshaw
    SheilaBradshaw Posts: 141
    Fiona, have you made sure that you've set your HRM with your correct weight, height etc? That makes a difference. I seem to find that my HRM always gives me a bigger burn than MFP or my Fitbit would for exercising. I've often wondered if it's because I have a large 'heart rate reserve', which means my heart beat has a wide range from 48 resting to 181 peak during workout (and I can still breath quite easily even at 181). Another friend I have says even when she's working flat out she never gets above 165. I wondered if people have a smaller heart range then perhaps their burn is smaller? Maybe someone who knows more about it can enlighten us :)

    The difference in what your HRM shows and what your FitBit shows is because the FitBit cannot track your heart rate so does not recognize that you are upping your intensity, therefore burning more calories.
  • DocMarr
    DocMarr Posts: 132 Member
    Fiona, have you made sure that you've set your HRM with your correct weight, height etc? That makes a difference. I seem to find that my HRM always gives me a bigger burn than MFP or my Fitbit would for exercising. I've often wondered if it's because I have a large 'heart rate reserve', which means my heart beat has a wide range from 48 resting to 181 peak during workout (and I can still breath quite easily even at 181). Another friend I have says even when she's working flat out she never gets above 165. I wondered if people have a smaller heart range then perhaps their burn is smaller? Maybe someone who knows more about it can enlighten us :)
    The '220-age' for maximum HR is just a general average for the population; an individual can have a maxHR that is up to 30 beats higher or lower than their predicted value. So doing a maxHR test on a treadmill, while it sucks, provides valuable information. Also, a good HRM should account for vO2max, or your aerobic fitness. If Lance Armstrong and I are riding bikes at the same speed, his HR is going to be lower than mine even though we're doing the same amount of work. Many Polar HRMs will use this number to adjust your calorie burn.

    And if your HRM doesn't have a chest strap, don't bother - it's not going to provide any more accurate information than the website estimates.

    Thanks for what you said although, if I'm honest, a lot of it went over my head. ( v02max? Lance Armstrong? - not heard of him, although I'm assuming he's a famous athlete person from the context) My hrm does have a chest strap (it's not a Polar). If my heart beats 30 beats higher or lower than average for my age group, does that make a difference to how many calories are burnt? (that was my actual question). I wouldn't know how or where to go about getting a maxHR test on a treadmill and I'm not sure why it might be worth doing? I really just use my hrm and fitbit to give me a bit more info about what I burn in the day but in the end it is only a guide to my fitness and calorie burn. It doesn't feature too heavily in my decision making about what I eat.
  • YoungerNextYear59937
    YoungerNextYear59937 Posts: 90 Member
    Love my FT7
  • meerkat70
    meerkat70 Posts: 4,605 Member
    HRM are the best and most accurate. APPs LIKE Endomando, MFP and other over est by at least 20%. Since i've purchased my HRM i would compare and its always over est. Invest in a HRM if possible.

    Could I ask about the basis for this view? It's being pretty strongly asserted on this thread by several people. I wondered what the evidence base is?
  • YoungerNextYear59937
    YoungerNextYear59937 Posts: 90 Member
    Thanks for what you said although, if I'm honest, a lot of it went over my head. ( v02max? Lance Armstrong? - not heard of him, although I'm assuming he's a famous athlete person from the context) My hrm does have a chest strap (it's not a Polar). If my heart beats 30 beats higher or lower than average for my age group, does that make a difference to how many calories are burnt? (that was my actual question). I wouldn't know how or where to go about getting a maxHR test on a treadmill and I'm not sure why it might be worth doing? I really just use my hrm and fitbit to give me a bit more info about what I burn in the day but in the end it is only a guide to my fitness and calorie burn. It doesn't feature too heavily in my decision making about what I eat.




    Wow! Really?!
  • YoungerNextYear59937
    YoungerNextYear59937 Posts: 90 Member
    .
  • kjw1031
    kjw1031 Posts: 300 Member

    Funny, I find MFP hundreds low compaired to my HRM, but fairly close to the treadmill's #s if I have the incline up a little.

    Me too. Based on my level of perceived exertion and what my HRM says, I think MFP actually low-balls me.

    I average the two numbers (MFP and my HRM) and go with that.
  • jonchew
    jonchew Posts: 239 Member
    Today's workout: My HRM/Endomondo told me that I burned 1066kCal, & MFP came-in at 959kCal... today it was fairly close. When you take-into account all of the variables (at least when running), such as pace, intensity, geography (hills) and wind - the actual calories really vary from day to day, even on the same course. I think MFP does a great job at guestimating calories burned, they have very little information to go on, after all.
  • meerkat70
    meerkat70 Posts: 4,605 Member
    I've seen how far off MFP is in every activity and I just accept that I burn much less. I still find it confusing, is everyones numbers so far off? If so, why?

    It's a conspiracy. MFP gives you a high number for calories burned then tells you to eat them or else you go into starvation mode.

    So you eat all false those exercise calories and cannot lose weight. This makes you stay here longer and see all the ads that many more times.

    It's genius. They are winning. How many posts do you see that say..."I'm doing everything right and still can't lose weight"?

    And just because I'm paranoid, doesn't mean they're not watching me... :-D
  • JennafurC
    JennafurC Posts: 65 Member
    My HRM also is always much higher than MFP gives me. My typical burn for an hour of zumba is about 550 on my HRM and on MFP its less than 300. Today I did a 90 minute zumba/kickboxing class and MFP gave me 445 calories burned and my HRM was about 850.
  • Azdak
    Azdak Posts: 8,281 Member
    HRM are the best and most accurate. APPs LIKE Endomando, MFP and other over est by at least 20%. Since i've purchased my HRM i would compare and its always over est. Invest in a HRM if possible.

    Could I ask about the basis for this view? It's being pretty strongly asserted on this thread by several people. I wondered what the evidence base is?

    I believe the basis is "groupthink" -- if something is repeated enough times, people start to believe it, regardless of whether it is true or not.

    What I don't understand is why people will dismiss machines, MFP, etc without a second thought, yet accept HRM numbers without any question whatsoever. Especially since they don't know the source of the data, or underlying methodology for ANY of those sources.

    I have written about these subjects numerous times. If anyone has the time or interest to go into more detail, you can visit

    http://www.myfitnesspal.com/blog/Azdak

    and go through some of the different related articles.
  • Smurfette1987
    Smurfette1987 Posts: 110 Member
    Thanks, I will read these. I have been finding that when I wear my chest strap on the treadmill the numbers are pretty much the same as what a calorie burn calculator based on average heart rate will give me, and still higher than my watch. I think I'll just have to get a decent watch.
    As for large heart rate reserves burning more, My resting heart rate is between 55-65 and I often go up to 185 during intervals and can still talk, and running 7.5 mph constantly it's about 170, sometimes doing insanity it goes up to the 190s and then I don't love it so much. I would say that's a reasonable heart rate reserve, but I still burn 400 cals per hr (really pushing myself) according to my watch, when mfp says 800+ :(

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