HRM overestimating?

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kelleybean1
kelleybean1 Posts: 312 Member
in Health and Weight Loss
I did my a.m. workout eight training (P90X arms and shoulders) took 50 min and my HRM says I burned 517 calories. Does this seem high to anyone else? I was working by butt off but that sure is a big burn! Opinions? I'm female, 53 yrs old, 5'[5" and 147 lbs.

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  • rhapsodygirl
    rhapsodygirl Posts: 23
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    What kind of HRM do you have? I have a PolarFT7 and when I walk at a fast pace on my treadmill for 70 minutes, it says I burn 538 calories. I'm 56 years old, 5ft.4 at 105 pounds. So, I would say that yours is pretty accurate.
  • aquarabbit
    aquarabbit Posts: 1,622 Member
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    I have a Polar too and find that it's accurate even though it seems high. I'm doing Body Revolution and when I hit over 300 in 30 minutes I didn't believe it. I found other sites that had records of a few people's calorie burns and while mine was high (I was also heavier than the people I found), it was still within that range. So I believed it after that.
  • MallorieGreiner
    MallorieGreiner Posts: 135 Member
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    I have a Polar FT4...I'd say HRM are pretty accurate. HRMs take your height, weight, age, and heart rate in order to calculate your calories burned...that combo makes for a good reading.
  • thekcpiper
    thekcpiper Posts: 12
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    I did my a.m. workout eight training (P90X arms and shoulders) took 50 min and my HRM says I burned 517 calories. Does this seem high to anyone else? I was working by butt off but that sure is a big burn! Opinions? I'm female, 53 yrs old, 5'[5" and 147 lbs.

    This translates to 10.34 kcal/min or roughly 2L/min of O2 (for the average person). Based on your age, weight and gender your BMR is about 1350 per day. The average person consumes 3.5 mL/min/kg of O2, which makes your resting consumption 0.233 L/min (roughly 1.17 kcal/min rest * 1440 min/day = 1680 BMR, so your resting O2 consumption is closer to 2.81 mL/min/kg, it varies - mine is 3.1). 2L/min would be 8.55 METS, which is the equivalent of running 4.9 - 5.0 mph on a treadmill with no incline. If you have an average VO2 for a 53/F (32.5 mL/kg/min or 2.171 L/min @ 147 lbs) and if I had to guess your HR during the exercise I'd say it was close to 92% MHR (167) or around 153 bpm +/- 5 bpm. If this is the range on your device then the count is probably accurate.

    Since I'm not familiar with your HR device, that's why I have the +/- , some devices record more accurately than others. But IMO, 517 kcal in 50 min for your age, weight and gender sounds reasonable.
  • kelleybean1
    kelleybean1 Posts: 312 Member
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    LOL, kcpiper, you totally lost me on that first paragraph!! I have a Polar FT7, btw. I guess I'll start eating then if it's accurate! Thanks!
  • thekcpiper
    thekcpiper Posts: 12
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    LOL, kcpiper, you totally lost me on that first paragraph!! I have a Polar FT7, btw. I guess I'll start eating then if it's accurate! Thanks!

    It should be close. Do you know your average HR for that exercise session? More info than you probably needed, but I always like to show my work LOL.

    Also, to account for food labeling inaccuracies and/or possible over-reporting of calories burned, I typically eat back only 2/3 of my exercise calories.

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