Heart Rate Monitor accuracy

disturbed_s
disturbed_s Posts: 40 Member
in Fitness and Exercise
So I've been using my machines 'Calories' burned function when adding my exercise to my diary and this is usually anywhere between 200 and 500 depending on how long etc obviously. Well yesterday I bought myself a HRM (chest strap and watch) and after today's workout it tells me I burned 925 cals as opposed to 600 from machine. Now I'm assuming a HRM would be a lot more accurate than a machine as it takes into account my age, weight, sex etc but, since logging I have not lost much weight at all and going by my effort could it be something to do with the difference? Hope this makes some sort of sense. Thanks

Replies

  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
    There are 8 billion threads on this...

    I just don't have the energy anymore.
  • IsaackGMOON
    IsaackGMOON Posts: 3,358 Member
    Here's what I've found.

    Machines: under compensate
    MFP: over/under compensates
    HRM: pretty darn close

    But of course, this is open to debate, there's about 200000000000000000000000000000000 threads on this topic.
  • rileysowner
    rileysowner Posts: 8,329 Member
    Is it set up properly. Age, Height, Weight, and Sex are all necessary and need to be correct. There are often other settings that will make it ever more accurate depending on the HRM manufacturer. If if does not have all the ones listed at the start, it will be less accurate. For example if it has Age, Height, Weight, but not Sex then it would not be accurate since men generally burn more calories than women because of their higher muscle mass.

    This may help http://www.myfitnesspal.com/topics/show/429688-new-hrm-how-to-make-the-calorie-estimate-more-accurate
  • _whatsherface
    _whatsherface Posts: 1,235 Member
    Today my cardio machine said I burned 769. My HRM said 520. HRM is more accurate. I'm surprised your machine gave you less calories then your HRM. For me, it's always been the other way around.
  • disturbed_s
    disturbed_s Posts: 40 Member
    Ok thanks, since I haven't been here long and new to this I'll go look for the millions of other threads thanks for the advice :)
  • Kevalicious99
    Kevalicious99 Posts: 1,131 Member
    This is a topic that many many people get wrong here (and the answers often reflect that) ... they are not as precise as people think they are. They seem to have a magical aura here at MFP.

    A HRM can only do ONE thing .. measure your heart rate. People always forget this major part of the equation.

    The rest is a mathematical calculation some programmer developed. Guess what .. the calorie burn is an estimate at best. They may be very out.

    For example ...
    I walked for 3 hours and my Polar HRM said I burned 1998 calories, guess what .. didn't happen. It way overestimated.

    You should probably use about 60% of the number that your HRM gives you if you are eating any of those calories back.
  • BrianSharpe
    BrianSharpe Posts: 9,248 Member
    Actually many heart rate monitors are wildly inaccurate as the algorithms used correlate heart rate to caloric expenditure and the relationship is not linear.

    Two people of equal weight will burn approximately the same amount of energy to sun a given distance irrespective of the fact that one may be fitter than the other - it's physics, mass over distance, yet many HRMs would estimate a much higher caloric burn for the out of shape person with the higher heart rate.

    What type a machine were you on and for how long?
  • 34blast
    34blast Posts: 166 Member
    As mentioned before, if you enter all the weight, age, height etc, the estimates should be close from the machines, heart monitor, and MFP. Also, make sure you have your heart rate up 60% or greater. Mine are all within 10% of each other. MPF, Polar FT-7, and cardio machines.

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