HRM calorie estimate greater than machines?

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MeleahR
MeleahR Posts: 5 Member
in Fitness and Exercise
I recently bought a HRM (Polar H7 with chest strap) for a more accurate calorie count. From reading posts here, I was led to think that gym machines OVER estimate calories burned. But I'm finding the opposite to be true for me.

Here's an example from my workout today:
Female
Age: 26
Height: 5'4
Weight: 133
Average Heart Rate: 156
Duration: 55 mins

Machine read: 310 calories burned
HRM read: 520 calories burned

That's a significant difference. This keeps happening on other machines too. Has anyone had similar experiences? Should I trust the HRM?

Replies

  • bevmcarthur
    bevmcarthur Posts: 341 Member
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    i would like to know the same thing. i am thinking of buying a new HRM .
  • cwolfman13
    cwolfman13 Posts: 41,874 Member
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    For one thing, it's all an estimate. Secondly, do you have any health conditions like a high RHR, hypertension, etc...if you do then a HRM is going to be pretty much worthless for you for calorie burn...they will all be highly inflated. Also, if you are substantially out of shape, your HR is going to be higher than it would be if you were in better shape...all other things being equal, that would also inflate your burn because your high HR is just a bi-product of your physical fitness and not a very good indicator at that point to a true level of VO2 max.

    I would also add that a couple hundred calories difference really isn't that substantial...it is well within the realm of estimation error for any of this...you will never, ever, ever know exactly to the dot how many calories you are truly burning doing anything. It's all an estimate. If you're using the MFP method and eating back calories then go with the most conservative estimate...the important thing is that you're giving yourself some fuel for that additional activity and not completely depriving your body of that nutrition. If you're doing some other method like TDEE then I really don't see the point in worrying about what the calorie burn is at all.

    Ultimately, you have to make adjustment to your intake as per real world results on the scale and with measurements...
  • 12pillows
    12pillows Posts: 81 Member
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    I'm pretty confident with mine, but the differences between my HRM and the machines isn't as drastic as that.

    Obviously there is no way to know for sure how many I'm burning, but here's an example.

    I used to use the stepper machine a lot because it told me I was burning a LOT of calories using it.
    I lost weight.
    To vary up my gym routine I switched to the bike, even though it gave me a lower read on calories burnt.
    I lost more weight.

    I got a HRM and used it doing both activities for a decent amount of time. According to the HRM I burnt a bit more than the machine said on the bike, and less than the machine said on the stepper.
    Based on my experience this seems accurate.

    I'm not too focused on the numbers, cause generally I don't eat back most of my exercise calories, but it gives me confidence when I run or cycle outside that I know how much I'm doing :)

    Oh and mine's the polar FT4

    (Edit to fix typo)
  • amberj32
    amberj32 Posts: 663 Member
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    For one thing, it's all an estimate. Secondly, do you have any health conditions like a high RHR, hypertension, etc...if you do then a HRM is going to be pretty much worthless for you for calorie burn...they will all be highly inflated. Also, if you are substantially out of shape, your HR is going to be higher than it would be if you were in better shape...all other things being equal, that would also inflate your burn because your high HR is just a bi-product of your physical fitness and not a very good indicator at that point to a true level of VO2 max.

    Is this really true about having a high RHR and/or hypertension and HRM calorie burn being highly inflated? I was planning on buying a HRM but what's the point if it's not very accurate either?
  • Francl27
    Francl27 Posts: 26,372 Member
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    I haven't used my HRM on machines at the gym for a while but it was also giving me more calories than the treadmill a year ago.

    I used it today on my stationary bike though ($100 on amazon, best purchase ever) and was shocked when I realized that the calorie burn was exactly the same for both... and I never even entered my weight or anything. So weird. I guess it doesn't matter with bikes how heavy you are?
  • hermann341
    hermann341 Posts: 443 Member
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    Are your height/weight/age/sex entered into the HRM and/or machine? The default settings are typically for a 150 lb male.
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
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    For one thing, it's all an estimate. Secondly, do you have any health conditions like a high RHR, hypertension, etc...if you do then a HRM is going to be pretty much worthless for you for calorie burn...they will all be highly inflated. Also, if you are substantially out of shape, your HR is going to be higher than it would be if you were in better shape...all other things being equal, that would also inflate your burn because your high HR is just a bi-product of your physical fitness and not a very good indicator at that point to a true level of VO2 max.

    Is this really true about having a high RHR and/or hypertension and HRM calorie burn being highly inflated? I was planning on buying a HRM but what's the point if it's not very accurate either?

    Yes. The HRM assumes the higher HR is due to exertion when in this case it is not. You will get a higher burn.

    OP -
    You may want to check out this thread, it will help you test to see how accurate you HRM is and gives suggestions on better setup
    http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is

    Also

    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn


    Another good read
    http://www.myfitnesspal.com/blog/Azdak/view/the-real-facts-about-hrms-and-calories-what-you-need-to-know-before-purchasing-an-hrm-or-using-one-21472

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