Using HRM to calculate TDEE

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isazzzz
isazzzz Posts: 95
in Fitness and Exercise
I do not have a fitbit and do not intend to get one anytime soon so I was just wondering if I can use my Polar for a day just to see how much my body actually burns a day.. I've been reading forums about how online TDEEI calculators are highly inaccurate.

My stats
5"1
44.5 kgs

Replies

  • Helloitsdan
    Helloitsdan Posts: 5,564 Member
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    Wear it for a week and on the food notes in your diary, log the burn.
    So if you burn 3k today log it!

    what I do is check my Fitbit at about 12pm every day.
    I take the number of calories burned, lets say 1190, and divide it by 12.
    In theory if I maintain that pace for the majority of the day...1190/12=99.16

    99.16x12=1189...1189+1190=2379.
    If cutting calories I would want to eat about 1800-1900.
    I dont eat till after 2pm daily so that means I could then set up my diary and maintain my cut.
    =D
  • love4fitnesslove4food_wechange
    love4fitnesslove4food_wechange Posts: 6,897 Member
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    Well I'd hope you aren't trying to lose and being 5'1 and 98 pounds you could stand to gain a few pounds--so I'd recommend eating the same number of calories daily for 3 weeks--say 1900--and weigh yourself before you begin and after (3 consecutive days each time) and average the weights before and after. Then compare. If you're within a pound of your start weight then continue eating that amount--if you're not then adjust as needed. This will be more precise than any other method if you're diligent about logging and calculating your intake--you also need to maintain a certain activity level for the information to be useful.
  • dad106
    dad106 Posts: 4,868 Member
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    HRM's are not meant to be worn at rest.. So any number you do get will be highly inaccurate and should be disregarded.

    If you really want to figure out what you burn in a day, then you need either a fitbit or a body media fit.
  • sarahkatara
    sarahkatara Posts: 826 Member
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    HRM's are not meant to be worn at rest.. So any number you do get will be highly inaccurate and should be disregarded.

    If you really want to figure out what you burn in a day, then you need either a fitbit or a body media fit.

    100% true. I tried it for one day and while i was sitting at my desk my heart rate would "shoot up" to 260 BPM. it's only meant to be worn during higher intensity movements. Also, there are accurate TDEE calculators, if you're willing to take the time to use them correctly. This one is accurate and easy: http://www.health-calc.com/diet/energy-expenditure-advanced
  • MoveTheMountain
    MoveTheMountain Posts: 764
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    I do not have a fitbit and do not intend to get one anytime soon so I was just wondering if I can use my Polar for a day just to see how much my body actually burns a day.. I've been reading forums about how online TDEEI calculators are highly inaccurate.

    My stats
    5"1
    44.5 kgs

    I just did this last week. Seemed to more or less line up with my BMR from an online calculator (within +/-150 calories, I think). One thing that was amazing was just how low my metabolim gets during the workday from sitting at a computer. I actually graphed is across the day, over an 8-hour period, and it just kept going lower and lower.
  • MoveTheMountain
    MoveTheMountain Posts: 764
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    HRM's are not meant to be worn at rest.. So any number you do get will be highly inaccurate and should be disregarded.

    If you really want to figure out what you burn in a day, then you need either a fitbit or a body media fit.

    100% true. I tried it for one day and while i was sitting at my desk my heart rate would "shoot up" to 260 BPM. it's only meant to be worn during higher intensity movements. Also, there are accurate TDEE calculators, if you're willing to take the time to use them correctly. This one is accurate and easy: http://www.health-calc.com/diet/energy-expenditure-advanced

    I'm not sure I agree with either of these... My Polar actually has a 'fitness test' that is designed specifically to be engaged while you're sitting or lying down. What do you base your conclusion on that HRMs are 'highly inaccurate and should be disregarded' while worn at rest? Your heart beat is your heart beat, and if it's measuring your heart rate, then that should be as accurate as any other conditions under which it's measuring your heart beat.

    (If your HR shot up to 260 sporadically, I would suggest that something might be wrong with either your HRM or your HR...)
  • mcarter99
    mcarter99 Posts: 1,666 Member
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    It measures your heart rate while at rest but the calorie calculations are usually designed to work for elevated heart rates, not resting.

    It'd be an easy thing to test. Wear it in bed at night and check your calorie burn in the morning. You should know a rough estimate of what you burn from TDEE calculators.

    The best way to calc your own TDEE is log every calorie you take in for a month and compare your beginning weight to your end weight. Even a HRM at elevated HR is just an estimate based on averages amongst the population.
  • dad106
    dad106 Posts: 4,868 Member
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    HRM's are not meant to be worn at rest.. So any number you do get will be highly inaccurate and should be disregarded.

    If you really want to figure out what you burn in a day, then you need either a fitbit or a body media fit.

    100% true. I tried it for one day and while i was sitting at my desk my heart rate would "shoot up" to 260 BPM. it's only meant to be worn during higher intensity movements. Also, there are accurate TDEE calculators, if you're willing to take the time to use them correctly. This one is accurate and easy: http://www.health-calc.com/diet/energy-expenditure-advanced

    I'm not sure I agree with either of these... My Polar actually has a 'fitness test' that is designed specifically to be engaged while you're sitting or lying down. What do you base your conclusion on that HRMs are 'highly inaccurate and should be disregarded' while worn at rest? Your heart beat is your heart beat, and if it's measuring your heart rate, then that should be as accurate as any other conditions under which it's measuring your heart beat.

    (If your HR shot up to 260 sporadically, I would suggest that something might be wrong with either your HRM or your HR...)

    Your fitness test is to figure out your VO2Max so estimated calorie burns are more accurate during exercise.. but that does not mean that they are meant to be worn all day.

    The formulas HRM's use to estimate calories burned is designed around when your heart rate is raised during exercise.. Not when you are just lying around watching TV. Also HRM's are only designed to be used during steady state cardio(IE walking, running, etc) and not during strength training, circuit training, etc.

    HRM's when used correctly(IE steady state cardio) are only 80% accurate... and used in any other condition, other then what they were designed for makes them inaccurate.
  • MoveTheMountain
    MoveTheMountain Posts: 764
    Options
    HRM's are not meant to be worn at rest.. So any number you do get will be highly inaccurate and should be disregarded.

    If you really want to figure out what you burn in a day, then you need either a fitbit or a body media fit.

    100% true. I tried it for one day and while i was sitting at my desk my heart rate would "shoot up" to 260 BPM. it's only meant to be worn during higher intensity movements. Also, there are accurate TDEE calculators, if you're willing to take the time to use them correctly. This one is accurate and easy: http://www.health-calc.com/diet/energy-expenditure-advanced

    I'm not sure I agree with either of these... My Polar actually has a 'fitness test' that is designed specifically to be engaged while you're sitting or lying down. What do you base your conclusion on that HRMs are 'highly inaccurate and should be disregarded' while worn at rest? Your heart beat is your heart beat, and if it's measuring your heart rate, then that should be as accurate as any other conditions under which it's measuring your heart beat.

    (If your HR shot up to 260 sporadically, I would suggest that something might be wrong with either your HRM or your HR...)

    Your fitness test is to figure out your VO2Max so estimated calorie burns are more accurate during exercise.. but that does not mean that they are meant to be worn all day.

    The formulas HRM's use to estimate calories burned is designed around when your heart rate is raised during exercise.. Not when you are just lying around watching TV. Also HRM's are only designed to be used during steady state cardio(IE walking, running, etc) and not during strength training, circuit training, etc.

    HRM's when used correctly(IE steady state cardio) are only 80% accurate... and used in any other condition, other then what they were designed for makes them inaccurate.

    Sorry, but your middle paragraph is only restating what you said earlier... what's the cutoff for when activity becomes exercise? How is that calculated off your base heart rate? I've heard this stuff before, but no one is ever able to offer anything specific about why the algorythm is faulty at lower heart rates and more accurate at higher heart rates - what's the mechanism that allows it to be accurate at higher heart rates, and what's the threshold between inaccuracy and accuracy?
  • dad106
    dad106 Posts: 4,868 Member
    Options
    HRM's are not meant to be worn at rest.. So any number you do get will be highly inaccurate and should be disregarded.

    If you really want to figure out what you burn in a day, then you need either a fitbit or a body media fit.

    100% true. I tried it for one day and while i was sitting at my desk my heart rate would "shoot up" to 260 BPM. it's only meant to be worn during higher intensity movements. Also, there are accurate TDEE calculators, if you're willing to take the time to use them correctly. This one is accurate and easy: http://www.health-calc.com/diet/energy-expenditure-advanced

    I'm not sure I agree with either of these... My Polar actually has a 'fitness test' that is designed specifically to be engaged while you're sitting or lying down. What do you base your conclusion on that HRMs are 'highly inaccurate and should be disregarded' while worn at rest? Your heart beat is your heart beat, and if it's measuring your heart rate, then that should be as accurate as any other conditions under which it's measuring your heart beat.

    (If your HR shot up to 260 sporadically, I would suggest that something might be wrong with either your HRM or your HR...)

    Your fitness test is to figure out your VO2Max so estimated calorie burns are more accurate during exercise.. but that does not mean that they are meant to be worn all day.

    The formulas HRM's use to estimate calories burned is designed around when your heart rate is raised during exercise.. Not when you are just lying around watching TV. Also HRM's are only designed to be used during steady state cardio(IE walking, running, etc) and not during strength training, circuit training, etc.

    HRM's when used correctly(IE steady state cardio) are only 80% accurate... and used in any other condition, other then what they were designed for makes them inaccurate.

    Sorry, but your middle paragraph is only restating what you said earlier... what's the cutoff for when activity becomes exercise? How is that calculated off your base heart rate? I've heard this stuff before, but no one is ever able to offer anything specific about why the algorythm is faulty at lower heart rates and more accurate at higher heart rates - what's the mechanism that allows it to be accurate at higher heart rates, and what's the threshold between inaccuracy and accuracy?

    It's faulty at lower heart rates because the algorithm used is made for an elevated heart rate like you would find during exercise... It's not made for a heart rate that you would find while resting.

    When you exercise, the HRM takes your max heat rate and what heart rate you are working at and then turns that into a percentage of max heart rate(60,70,80,90,100) of max heart rate. It then takes that percentage and uses other factors like age, weight, height and gender and to estimate calories burned.

    Unless you have a really low max heart rate, it's not going to fall into any of the percentages stated above.. and hence why it would be inaccurate.

    Read those two links.. he explains it best.

    http://www.myfitnesspal.com/blog/Azdak?month=201112
    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
  • Martina_Who
    Martina_Who Posts: 172 Member
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    Things for asking this and all the replies!
    I was wondering this too!
    Must save up for a fitbit now!

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