Why do I not burn as much?

Nathalia2009
Nathalia2009 Posts: 75 Member
in Fitness and Exercise
I do 1 hour kick boxing classes. They are pretty intense. I have a polar HRM. When I started working out about 6 months ago it would tell me I was burning anywhere between 650-710 calories. The instructor states everyone should burn 500-700 in her class. I used my HRM this past week and it only showed me to burn 450 calories. I am going at it hard. The class is still very intense. Since i started I have lost about 34ish pounds. This may be a dumb questions but....as you loose weight do you not burn as many calories ? Or do you think there is something wrong with my HRM?

Replies

  • asdowe13
    asdowe13 Posts: 1,951 Member
    As you lose weight you will burn fewer calories.

    As you strengthen your heart and body you will burn fewr calories.
  • 4legsRbetterthan2
    4legsRbetterthan2 Posts: 19,590 MFP Moderator
    As you lose weight you will burn fewer calories.

    As you strengthen your heart and body you will burn fewr calories.

    yup yup
  • xcalygrl
    xcalygrl Posts: 1,897 Member
    As you lose weight you will burn fewer calories.

    As you strengthen your heart and body you will burn fewr calories.

    Agree with this.

    Side note: if you are adding muscle, you will burn more calories at rest even if you don't see it on your HRM.
  • Nathalia2009
    Nathalia2009 Posts: 75 Member
    Thank you ! I liked seeing 650 on my HRM lol...but I guess it is a good sign that I a not =)
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    As you lose weight you will burn fewer calories.

    As you strengthen your heart and body you will burn fewr calories.

    Not exactly.

    As you lose weight, you will burn fewer calories, yes. You have less mass to move, so it requires less energy.

    But, fitness level does not affect calories burned. It will affect the reading on your HRM unless you are able to adjust for VO2 max, but that does not mean it is correct.

    Azdak also gives a great explanation here
    http://www.myfitnesspal.com/topics/show/1318788-relationship-between-weight-fitness-hr-cals-burned

    A few great blog on the topic
    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
  • asdowe13
    asdowe13 Posts: 1,951 Member
    Thank you ! I liked seeing 650 on my HRM lol...but I guess it is a good sign that I a not =)

    Getting Healthy is awesome!
  • brianpperkins
    brianpperkins Posts: 6,124 Member
    Thank you ! I liked seeing 650 on my HRM lol...but I guess it is a good sign that I a not =)

    What you saw on your HRM was skewed to begin with. HRMs are pretty good at estimating calories burned for specific steady state cardio activities like running, cycling, etc. They are not programmed for, nor are they accurate at estimating calories for kickboxing, Zumba, intervals, etc.
  • asdowe13
    asdowe13 Posts: 1,951 Member
    All calories burned are estimates.

    HRM offer the best estimate IMO - they may not be programmed but they will still give a best guess.
  • sijomial
    sijomial Posts: 19,809 Member
    As you lose weight you will burn fewer calories.
    True
    As you strengthen your heart and body you will burn fewer calories.
    False. Your HRM may tell you that but it doesn't mean it's true.
    Side note: if you are adding muscle, you will burn more calories at rest even if you don't see it on your HRM.
    True but the effect is insignificant.

    Good news is you are getting fitter.
  • erickirb
    erickirb Posts: 12,294 Member
    I would guess is that as you became more fit your HR does not get as high for as long, that's a good thing (stronger heart), and if you weigh less you will burn less as you are moving less mass.
  • asdowe13
    asdowe13 Posts: 1,951 Member
    As you strengthen your heart and body you will burn fewer calories.
    False. Your HRM may tell you that but it doesn't mean it's true.

    Any references on this? Not saying you are wrong, I probably am, Just looking to learn more
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    As you strengthen your heart and body you will burn fewer calories.
    False. Your HRM may tell you that but it doesn't mean it's true.

    Any references on this? Not saying you are wrong, I probably am, Just looking to learn more

    I posted two links above that get into a more detailed explanation.
  • asdowe13
    asdowe13 Posts: 1,951 Member
    As you strengthen your heart and body you will burn fewer calories.
    False. Your HRM may tell you that but it doesn't mean it's true.

    Any references on this? Not saying you are wrong, I probably am, Just looking to learn more

    I posted two links above that get into a more detailed explanation.

    I read them, but looking for more facts - studies!
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    As you strengthen your heart and body you will burn fewer calories.
    False. Your HRM may tell you that but it doesn't mean it's true.

    Any references on this? Not saying you are wrong, I probably am, Just looking to learn more

    I posted two links above that get into a more detailed explanation.

    I read them, but looking for more facts - studies!

    Heybales references a study here
    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn

    And a few other are referenced here
    http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is.

    ETA -
    Both of this guys have provided references in the past, that was just a quick search for them. You could probably even PM them for more info.
  • iplayoutside19
    iplayoutside19 Posts: 2,304 Member
    A calorie is a unit of energy.

    The more weight there is to move...the more calories (energy) are required to move that weight.
  • kaotik26
    kaotik26 Posts: 590 Member
    Your getting into better cardiovascular shape, so your heart rate is going to be lower at it's peak thus, less calories. That's pretty awesome actually that you have worked hard enough for your heart to be responding to it! Nice work!!
  • asdowe13
    asdowe13 Posts: 1,951 Member
    As you strengthen your heart and body you will burn fewer calories.
    False. Your HRM may tell you that but it doesn't mean it's true.

    Any references on this? Not saying you are wrong, I probably am, Just looking to learn more

    I posted two links above that get into a more detailed explanation.

    I read them, but looking for more facts - studies!

    Heybales references a study here
    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn

    And a few other are referenced here
    http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is.

    ETA -
    Both of this guys have provided references in the past, that was just a quick search for them. You could probably even PM them for more info.

    Thanks for the added info!
  • _Terrapin_
    _Terrapin_ Posts: 4,301 Member
    bump. . .unreal.
  • brianpperkins
    brianpperkins Posts: 6,124 Member
    All calories burned are estimates.

    HRM offer the best estimate IMO - they may not be programmed but they will still give a best guess.

    My bathroom scale isn't programmed to estimate my car's speed which is why I don't use it for that purpose.
  • asdowe13
    asdowe13 Posts: 1,951 Member
    All calories burned are estimates.

    HRM offer the best estimate IMO - they may not be programmed but they will still give a best guess.

    My bathroom scale isn't programmed to estimate my car's speed which is why I don't use it for that purpose.

    Wow that is a stupid comparison! Thanks for your useless insight!
  • brianpperkins
    brianpperkins Posts: 6,124 Member
    All calories burned are estimates.

    HRM offer the best estimate IMO - they may not be programmed but they will still give a best guess.

    My bathroom scale isn't programmed to estimate my car's speed which is why I don't use it for that purpose.

    Wow that is a stupid comparison! Thanks for your useless insight!

    For what the usual complaints are it is spot on .. using a tool incapable of providing the desired measurement then sniveling online about it. If people would simply take a few minutes and understand what a HRM can and can't do before buying one things get simple. Calling operator error a "best guess" is absolutely laughable. It's no wonder why useless diet pills, fad devices, and unhealthy diets make so much money ... ignorant buyers who then rationalize their purchase after the fact which does not make up for the lack of research done before hand.
  • meshashesha2012
    meshashesha2012 Posts: 8,329 Member
    hrm base your calorie burn on your heart rate using a formula so it's not really that accurate a measure of how much effort you actually putting in to get stuff done.

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