Discrepancy in Calories Burned

miabrown66
miabrown66 Posts: 70
edited September 23 in Fitness and Exercise
Does anybody know why there is such a large discrepancy between what a piece of exercise equipment/heart rate monitor shows for calories burned versus what is in the MFP database? I recently got a Polar HRM and the difference on my HRM and MFP is pretty drastic. For 60 minutes on MFP for cycling it shows 900+ calories burned vs. 317 for the HRM? Seems like a pretty big gap. I am using my HRM stats but just wondered about this. Thanks,

Replies

  • MoM2LayLa09
    MoM2LayLa09 Posts: 152
    wow... i don't know anything about it but am curious to know. i'm saving up for a hrm right now but i wonder how far off my 30 min aerobics is : /
  • MissLadyInWaiting
    MissLadyInWaiting Posts: 152
    MFP might assume that your heart rate is higher then it actually it, or that it thinks you are going faster then you really are. just go with the HRM, and even if the HRM is wrong and MFP is right you would rather be under-estimating your calories burned then over-estimating.
  • kgasser
    kgasser Posts: 333 Member
    C
  • BobbyDaniel
    BobbyDaniel Posts: 1,459 Member
    I noticed that when I got my HRM and I have noticed better results by using the HRM; the MFP numbers are more generic while your HRM is based on the calories you burn based on your HR.
  • RUNN3Rmom
    RUNN3Rmom Posts: 441
    I also wonder the same thing. I have a Polar too and today I burned 389 while doing running, elliptical and some light weights for one set and if I had logged cardio for an hour on MFP I would have had twice as much.

    I try to go by my HRM but man, it would be nice to burn 600 calories, LOL!
  • Micki_Berthelot
    Micki_Berthelot Posts: 4
    I'm glad you all brought this topic up and cleared it up too. One of my co-workers and I were discussing the amount of calories MFP charts as burned by exercise and it seemed way off to me. I've been using the heart rate monitor at the gym on the trainer prior to using MFP- I was using Livestrong before and had the same problem with it.


    url=http://www.myfitnesspal.com/weight-loss-ticker]4751542.png[/url]
    Created by MyFitnessPal.com - Nutrition Facts For Foods
  • jadedjade24
    jadedjade24 Posts: 127
    MFP gives an estimate of the calories burned, but since the website doesnt know how hard you were working it cant give you an honest reading.

    The HRM give you a more acurate reading because it factors in age/weight/HR/Gender so the readings are more correct.
  • USCErin
    USCErin Posts: 6
    Sounds like I better get a heart rate monitor. Today I did 20 minutes on a recumbent bike at the gym and at the end it said I'd only burned about 100 calories even though I was pedaling at a speed over 20mph! The HRM on the bike was not working.

    MFP said I burned 300, but that seemed high. I try to underestimate my exercise calories, just in case!

    Thanks for bringing up this topic!
  • chrisdavey
    chrisdavey Posts: 9,834 Member
    Even HRM's can differ. Azdak made a post a while back about the different formulas they use. To be on the safe side, just use the lowest number (if you are trying to lose weight).
  • miabrown66
    miabrown66 Posts: 70
    Thanks all. I have been using the lowest number. I don't like it, but I do! LOL!
  • Azdak
    Azdak Posts: 8,281 Member
    The more imprecise the intensity "categories" and descriptions are, the more variability you will see in calorie estimates.

    I have never used the MFP databases, but I looked at them enough to know that they suffer from the same shortcomings as all workout/activity databases.

    If you look up "Cycling, medium" what does that mean? It could mean 20 different things to 20 different people. Now if you could put in "Cycyling, stationary, 150 watts" you could calculate a calorie number that was pretty close, but most people do not have access to that level of precision.

    Simple, linear, steady-state activities such as walking and running will be pretty accurate. These activities have well-validated equations to predict energy expenditure and the movements do not have that much variability.

    Cross trainers (ellipticals) are VERY inaccurate because there is no common movement design. Every cross trainer movement is a little different. For real accuracy, a database would have to have developed specific algorithms for every make and model of cross trainer out there. Which is something even most of the manufacturers don't do.

    Group class activities will vary widely as well, depending on movement skill, fitness level, structure of the class, etc. No database can give anything more than just a vague estimate of calories burned during group class activities.

    HRMs can be very useful in some situations, not so much in others. I am not going into all the detail in this post, but suffice to say that HRM calorie counts are not a "gold standard" and you need to take the time and effort to learn how to set them up properly and the conditions under which they are accurate (and those that they aren't).
This discussion has been closed.

Categories