Body Media VS Polar

parkermegan
parkermegan Posts: 167
in Fitness and Exercise
Why is my calorie burn SO different? My Polar today was 504 and BM was 397. I know that I can't expect perfection but, that is a big difference.

Replies

  • jacksonpt
    jacksonpt Posts: 10,413 Member
    Um, because they are fundamentally different in how they work.
  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
    That's not actually a big difference, especially considering neither device actually measures calories.
  • parkermegan
    parkermegan Posts: 167
    What do you mean neither measures calories? A polar HRM is designed to show you your calorie burn....a BM is designed to show you how many calories you burn/eat a day? That makes no sense.

    Does anyone have a helpful response?
  • SmartAlec03211988
    SmartAlec03211988 Posts: 1,896 Member
    Trust the BodyMedia.

    Been using mine faithfully for over a year and it works.

    Anything that measures calories is simply an estimate, nothing will be exact, but it can give you a good idea how many you do and enable you to adjust accordingly.
  • Mr_Knight
    Mr_Knight Posts: 9,532 Member
    What do you mean neither measures calories? A polar HRM is designed to show you your calorie burn....a BM is designed to show you how many calories you burn/eat a day? That makes no sense.

    No, an HRM is designed to detect and track your heart rate. That's it. Using that heart rate, a bunch of math using a bunch of generalized assumptions is used to *guess* at your calorie burn. How accurate that guess is depends on how well you and your activity fit the assumptions.

    Again, neither device actually measures calories or anything to do with calories - they are like the blindfolded man trying to figure out the shape of an elephant using only his hands.
    Does anyone have a helpful response?

    What's with the attitude?
  • parkermegan
    parkermegan Posts: 167
    I do realize it's an estimate but, I am just curious as to how they measure since the difference is so great. I tend to think the chest strap with the polar would be a more accurate measurement??
  • jacksonpt
    jacksonpt Posts: 10,413 Member
    What do you mean neither measures calories? A polar HRM is designed to show you your calorie burn....a BM is designed to show you how many calories you burn/eat a day? That makes no sense.

    No, an HRM is designed to detect and track your heart rate. That's it. Using that heart rate, a bunch of math using a bunch of generalized assumptions is used to *guess* at your calorie burn. How accurate that guess is depends on how well you and your activity fit the assumptions.

    Again, neither device actually measures calories or anything to do with calories - they are like the blindfolded man trying to figure out the shape of an elephant using only his hands.
    Does anyone have a helpful response?

    What's with the attitude?

    Agreed on all accounts.
  • kikicooks
    kikicooks Posts: 1,079 Member
    I really don't know the science about it but I tend to go with what my BMF says over my HRM if they differ, HRM is usually the higher one. Many times they are actually pretty close but some exercise do read different from the 2, about 100 calories. Overall, on an average, the numbers I get from my BMF seem to be fairly accurate(after seeing gains and losses that made sense compared to what I burned/consumed) but I do know it's not 100% accurate, it's just a good guide for me.
  • SJCon
    SJCon Posts: 224
    Again, neither device actually measures calories or anything to do with calories - they are like the blindfolded man trying to figure out the shape of an elephant using only his hands.

    Actually the better analogy considering how much study and science have been done on each of these devices would be "a blindfolded man trying to ensure the shape of an elephant using only his hands after caring, tending and studying them for a decade without a blindfold The initial response to say they don't count calories although true appears to have merely been Toll Bait..

    To address the question, each day our body differs on how it handles stress (exercise) based on a large number of variables. You may have noticed your heart rate is generally higher on some days than others and may be harder to keep in the "Fat Burning" zone. The BM has the temperature and galvanic sensors to base the calories burn estimate on and the HRM uses only the heart rate. They will only match by coincidence and are often very close BUT not always. I have found that the BM tends to be more conservative and I would go with that. JMO

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