POLAR HRM vs MFP

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lahlie
lahlie Posts: 149 Member
in Fitness and Exercise
Ok. I need to clarification/reassurance/introspect into my measuring my calorie use during exercise. I have the Polar FT7 HRM, and it is set to my body. I went for a walk, pushing my twins in a stroller (80lbs between the two of them) for 3 miles....about 55 minutes. My HRM said I burned 626 calories. Now, MFP, shows that just walking for that amount of time at a leisurely pace, that I only burned 302 calories. I know it doesnt take into account my pushing a stroller, but what should I log? I have always never thought twice about trusting my Polar HRM, but now, I am not so sure....
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Replies

  • gemiwing
    gemiwing Posts: 1,525 Member
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    Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.
  • tinana_RN
    tinana_RN Posts: 541 Member
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    Log from your HRM. I push a stroller and use my HRM when I walk with the kids, I always take the HRM number over MFP.
  • erickirb
    erickirb Posts: 12,293 Member
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    how high was your HR?
  • Le_Joy
    Le_Joy Posts: 593 Member
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    I'd go with HRM over MFP, takes more of your personal info into account.
  • erickirb
    erickirb Posts: 12,293 Member
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    Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.

    The HRM does not know how hard she worked either, it uses HR to estimate intensity, but if you normally have a high HR, then your HRM will over estimate your burn as your HR does not accurately reflect the actual intensity.
  • harlanJEN
    harlanJEN Posts: 1,089 Member
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    HRM. Is connected to YOU .. MFP isn't : )
  • mellabyte
    mellabyte Posts: 193 Member
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    HRM all the way. :) MFP, I think, are general baseline estimates.
  • heddylyn
    heddylyn Posts: 173 Member
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    HRM definitely. MFP is just an estimate based on the average person (which is usually considered 150 pounds). You'll burn more or less depending on your weight and actual heart rate.
  • htolen
    htolen Posts: 28
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    I have the opposite problem; I don't have an HRM (yet!), but when I go to the gym and use the elliptical trainer, the machine will say that I burn about 660 calories for an hour-long workout. When I come home and log into MFP, if I plug in 60 minutes of elliptical training, MFP says I burn almost 900 calories. I always adjust the minutes that I enter on MFP to match the calories that the machine says I burned, because I think MFP numbers are very generalized and don't necessarily take into account the speed and intensity of my workouts whereas the machine at the gym does. I think. So I agree with what everyone else is saying: adjust the minutes or the intensity (instead of "slow pace," or "walking dog" pace, go for more intense walking) so that the MFP database logs what your HRM says you actually burned.

    I can't wait to get one of those HRMs...they are so cool!

    Good job on the exercising, too! :-)
  • SheehyCFC
    SheehyCFC Posts: 529 Member
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    Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.
    The HRM does not know how hard she worked either, it uses HR to estimate intensity, but if you normally have a high HR, then your HRM will over estimate your burn as your HR does not accurately reflect the actual intensity.
    His question about HR above will give a good indication... (what's your resting HR as well?). I would trust the HRM but not to a fault. Also realize that you need to subtract out your BMR calories from that... so if it was 1 hour of exercise, that is likely ~100 calories less you should be counting.

    **EDIT for clarity
  • ashreynolds09
    ashreynolds09 Posts: 257 Member
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    I have the exact same HRM and I always just override what MFP says and use what my HRM tells me. The HRM uses your heart rate to determine your calories burned. Your heart rate changes with your intensity levels. MFP just goes off of basic numbers...your current weight, age, and height --- (really, I have no idea I'm just assuming that it uses these) and what the average person with those stats would burn.
  • Hodar
    Hodar Posts: 338 Member
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    Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.
    No HRM knows how hard you worked. It 'assumes' your rest heart-rate is 'x' and then uses a table to look up instantaneous heart-rates over the 'x' value to calculate a total caloric burn. This is like looking at how may RPM's your engine is running, and predicting how fast you are driving and what direction. You simply do not have enough data to make this prediction. Are you sitting in your driveway with a fast idle? Are you spinning on ice? Are you flying downhill?

    My rest HR is 46 bpm, my wife has a rest HR of 88. I have to bust my butt to get it up to 108, my wife needs merely to walk across the street to get the mail. To say that our caloric burns are comparable based solely upon our HR is a bit of an exaggeration.

    To get an accurate caloric reading, the HRM would need to know YOUR average rest heart rate, you rate of conversion of O2 to CO2, your weight, the distance you are travelling, the speed at which you are travelling (we tend to 'jump' when we run, vs a smooth transaction when we walk). the starting and ending elevations, your age, fitness and gender - and that's just off the top of my head. A marathon runner will burn far less calories in a 1.5 mile jog than I will, simply because his body is tuned to this sort of thing - while mine is not.

    Everything we use is a 'best guess' - it's simply making due with lots of "Rules of Thumb".
  • gemiwing
    gemiwing Posts: 1,525 Member
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    OK you pedantic people you-

    How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.
  • JaySpice
    JaySpice Posts: 326 Member
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    OK you pedantic people you-

    How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.

    OMG! Yes! I mean dang, It may be off a bit but not by 300+ calories.
  • lahlie
    lahlie Posts: 149 Member
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    avg HR 182
    Max HR 197

    RHR usually in the high 70s low 80s
  • JaySpice
    JaySpice Posts: 326 Member
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    My rest HR is 46 bpm, my wife has a rest HR of 88. I have to bust my butt to get it up to 108, my wife needs merely to walk across the street to get the mail. To say that our caloric burns are comparable based solely upon our HR is a bit of an exaggeration.

    But doesn't the HRM take your resting HR in consideration? When I set up my HRM I put in my height and weight and allathat so when I start a work out it's close to my resting HR (if I haven't been running around the house looking for the dang thing). So if your resting HR is 46 then the HRM should know how hard you are working to get your HR up to 108...right?
  • lahlie
    lahlie Posts: 149 Member
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    Polar wins. MFP doesn't know how hard YOU worked to push- just an average for speed.
    The HRM does not know how hard she worked either, it uses HR to estimate intensity, but if you normally have a high HR, then your HRM will over estimate your burn as your HR does not accurately reflect the actual intensity.
    His question about HR above will give a good indication... (what's your resting HR as well?). I would trust the HRM but not to a fault. Also realize that you need to subtract out your BMR calories from that... so if it was 1 hour of exercise, that is likely ~100 calories less you should be counting.

    **EDIT for clarity

    on this particular workout
    avg HR 182
    max HR 197

    RHR usually in high 70s/low 80s
  • SheehyCFC
    SheehyCFC Posts: 529 Member
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    avg HR 182
    Max HR 197
    RHR usually in the high 70s low 80s
    That is EXTREMELY high HR... how hard were you struggling? Have you done this before and gotten those readings? If you weren't gasping for air nearly the whole time, I think something may be off...

    **EDIT - you just said you "walked" so I don't see how those numbers are possible. I would go by MFP in this case. Also, make sure the electrodes are properly positioned to get the most accurate reading possible
    OK you pedantic people you-

    How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.
    umm... in this case it could be that much considering she is seeing a HR that high (and it is more likely in the 140-150 range) for an entire HOUR
  • Meg_78
    Meg_78 Posts: 998 Member
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    Polar wins hands down, MFP estimates so low for me, almost by half sometimes.
  • lahlie
    lahlie Posts: 149 Member
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    avg HR 182
    Max HR 197
    RHR usually in the high 70s low 80s
    That is EXTREMELY high HR... how hard were you struggling? Have you done this before and gotten those readings? If you weren't gasping for air nearly the whole time, I think something may be off...

    **EDIT - you just said you "walked" so I don't see how those numbers are possible. I would go by MFP in this case. Also, make sure the electrodes are properly positioned to get the most accurate reading possible
    OK you pedantic people you-

    How off is a HRM normally? Enough to give an extra 200 cal burn? 300? 500? Fill me in.
    umm... in this case it could be that much considering she is seeing a HR that high (and it is more likely in the 140-150 range) for an entire HOUR

    No....I am in THAT bad of shape.... :/ Yes, I was huffing and puffing pretty much the whole time.

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