HRM says I burn twice the calories as online conversion?

kbarnick
kbarnick Posts: 36
in Fitness and Exercise
I just started using a heart rate monitor while working out, but am noticing a very large difference in the calories burned calculated by the HRM (it's a timex), and if I look up the conversion online (http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx).

For instance, today I did a game based dance workout. MFP usually calculates around 375 calories for a 50 min. workout, the online conversion I am using is telling me 475 calories, and my HRM is giving me 800! I'm not asking for an exact science here, but that number seams so much higher, it's hard for me to accept it as the calculation I should use. I have been using the online conversion (it takes amount of time+ weight+age+average HR).

Has anyone else had this large difference? What calculation do you use?

Replies

  • martinh78
    martinh78 Posts: 601
    I guess the obvious one is to check you've inputted the details in you HRM correctly. Ie your weight in kgs, not lbs for example?
  • kbarnick
    kbarnick Posts: 36
    Yeah, I just double checked that, it is set to Ibs, and so is everything else I am using.
  • martinh78
    martinh78 Posts: 601
    Not sure then. Seems odd the HRM would be so much higher tahn the online calc, especially if you are inputting your average heart rate from the HRM. They should be the same, or close I would have thought. Sorry, no idea.
  • numsquat
    numsquat Posts: 133
    Results depend on the formulas used by the manufacturer. I have a Timex and Polar and both gave different results with same data entered on both and used at the same time. Used an online calculator and got a third result.

    What I ended up doing is picking the one that gave me consistent data for the results I'm looking for, which ended up being a online calculator (and it's not the MFP calculations). With my calorie intake goals and results combined with the exercise calories I have been maintaining easily and consistently in my 5lb range. Nothing is totally accurate but this works for me.
  • BobSassafrass
    BobSassafrass Posts: 85 Member
    I have a Timex HRM that is almost always 100% off from what MFP and other online calcs say. From what I've read, the HRM usually uses a formula based on average people and average heart rates. But not every workout you do is strictly cardio and of course most of us do not have average bodies.

    So unless you spent a lot of money on a Polar or some other fancy brand of HRM, I wouldn't use the calorie count as gospel. MFP numbers seem to be much closer to reality in my opinion and I use them exclusively. Use the HRM to understand what zone your in, like making sure youre in a good heart rate zone to be burning calories and not too high to be unsafe.

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