Calories burned ? over 400lbs

AshleighFTM
AshleighFTM Posts: 18 Member
edited September 29 in Fitness and Exercise
I trust my HRM is accurate... but sometimes I wonder. Everything {charts, any website, mfp included} that estimates calories burned always has a much much much higher estimate then what is actually burned. {for someone of my weight}

My friend has a bodybugg and she walked with me this morning, we walked at the same pace, distance, time, etc. I burned 601 for 90 minutes and she burned 780. (She is 160 and 5'6". I am 410 and 6') I didn't look into her average HR for the walk, mine was 148.

Does anyone have experience with accuracy of HRMs over 400lbs? Should/does it matter? To be honest, it doesn't really matter, but I am very curious.

Oh I have a Polar ft7 and yes its programed to my specifics.

Replies

  • dracobaby82
    dracobaby82 Posts: 380 Member
    I would think that it is accurate... the only thing to remember is as you lose weight, you need to put it into your HRM... after I had lost like 20 pounds I realized I had it set at my starting weight, so once I changed it... I burned less calories lol
  • pauljsolie
    pauljsolie Posts: 1,024 Member
    The FT7 is a very good HRM. You can't compare yourself with someone smaller. She might be fueling more muscle than you. On the other hand, you are probably burning way more calories from your BMR than she is. Trust your HRM, it has your exact specifications in it and will not steer you wrong. Great burn, keep it up.
  • SeasideOasis
    SeasideOasis Posts: 1,057 Member
    In general, the more muscle you have the better 'burn' you get, per my doctor. This could account for the difference.

    HRMs, if used with a chest strap, are pretty darn accurate, though not perfect.
  • funkyspunky871
    funkyspunky871 Posts: 1,675 Member
    That does sound VERY peculiar. I would have probably expected someone of your height to burn 1000+ calories with 90 minutes of walking...

    Have you looked on the polar website for more information about HRMs and heavier customers? HRM's a typically accurate -- but I think your's might have issues. I'm not sure if it had something to do with your weight, but it sounds likely that it might.
  • AshleighFTM
    AshleighFTM Posts: 18 Member
    I would think that it is accurate... the only thing to remember is as you lose weight, you need to put it into your HRM... after I had lost like 20 pounds I realized I had it set at my starting weight, so once I changed it... I burned less calories lol

    LOL.. thanks for the reminder, I haven't updated it since my last weight in, but I doubt the three pounds makes that much a difference.
  • Blackthorne99
    Blackthorne99 Posts: 250 Member
    Years ago, when I was on a medical fast, the nutritionist who was guiding our progress talked about the 'calories burned' charts that we see. In most cases, they are designed for someone who is 150lbs, so a rule of thumb estimate for calories burned is (Your weight / 150 lbs ) x Calories burned on the chart. For easy figuring, let's say you were 300lbs. That would make your ratio an even 2.0 so you would be estimated as burning twice what the charts figure.

    Calories burned, in its simplest form, is how much energy it takes to move a specific amount of mass through space. The adjustments are made based on a) how much mass you are ACTUALLY moving (vs. what the charts estimate) and b) how far through space you are moving it.

    What I loved about her explanation was that she stated that CRAWLING a mile burned the same amount of calories as walking slowly and running as hard as you could - because you're still moving the same amount of mass the same distance. The difference between them was the SPEED at which you burned those calories. If you took 20 hours to crawl that mile, you burned the same 100 calories that someone did walking 3mph. They just burned it in 20 minutes, not 20 hours, thus leaving them TIME to burn additional calories.

    Now basal metabolism is different based on body fat percentage, but actual calories burned for exercise is not dependent on how much or how little muscle mass you have. That only affects how hard it feels for you - not whether or not you're burning more calories. Thus the reason why things that just make your heart race (like scary movies and sex) are not nearly as high calorie burners as climbing stairs.
  • AshleighFTM
    AshleighFTM Posts: 18 Member
    That does sound VERY peculiar. I would have probably expected someone of your height to burn 1000+ calories with 90 minutes of walking...

    Have you looked on the polar website for more information about HRMs and heavier customers? HRM's a typically accurate -- but I think your's might have issues. I'm not sure if it had something to do with your weight, but it sounds likely that it might.

    Thats around what most sites estimate. Even when I am elliptical or arc training... I would expect some huge burn but 30 minutes earns me roughly 300. I also burn about 160 doing 30DS. {seems like a normal burn for an average person}

    I will look into it more on there website. Thanks!
  • Azdak
    Azdak Posts: 8,281 Member
    I trust my HRM is accurate... but sometimes I wonder. Everything {charts, any website, mfp included} that estimates calories burned always has a much much much higher estimate then what is actually burned. {for someone of my weight}

    My friend has a bodybugg and she walked with me this morning, we walked at the same pace, distance, time, etc. I burned 601 for 90 minutes and she burned 780. (She is 160 and 5'6". I am 410 and 6') I didn't look into her average HR for the walk, mine was 148.

    Does anyone have experience with accuracy of HRMs over 400lbs? Should/does it matter? To be honest, it doesn't really matter, but I am very curious.

    Oh I have a Polar ft7 and yes its programed to my specifics.

    What was your walking pace? It sounds to me like both your devices are off.

    According the the established energy prediction equations, you were walking at 2.0 mph and she was walking at around 5 mph.

    The equations can be a little off when you start getting up to heavier weights. That is because the energy costs of breathing and general locomotion are higher - normally these are not included in energy estimates.

    The best general way to estimate calories with walking (up to 4.0 mph) is just to multiply walking speed in miles per hour times your body weight in kg. That will give you calories per hour and you can multiply that by the total hours (or fraction of an hour) that you walk. That should be close enough.

    What is important and awesome is that you are walking for 90 minutes.
  • Azdak
    Azdak Posts: 8,281 Member
    Years ago, when I was on a medical fast, the nutritionist who was guiding our progress talked about the 'calories burned' charts that we see. In most cases, they are designed for someone who is 150lbs, so a rule of thumb estimate for calories burned is (Your weight / 150 lbs ) x Calories burned on the chart. For easy figuring, let's say you were 300lbs. That would make your ratio an even 2.0 so you would be estimated as burning twice what the charts figure.

    Calories burned, in its simplest form, is how much energy it takes to move a specific amount of mass through space. The adjustments are made based on a) how much mass you are ACTUALLY moving (vs. what the charts estimate) and b) how far through space you are moving it.

    What I loved about her explanation was that she stated that CRAWLING a mile burned the same amount of calories as walking slowly and running as hard as you could - because you're still moving the same amount of mass the same distance. The difference between them was the SPEED at which you burned those calories. If you took 20 hours to crawl that mile, you burned the same 100 calories that someone did walking 3mph. They just burned it in 20 minutes, not 20 hours, thus leaving them TIME to burn additional calories.

    Now basal metabolism is different based on body fat percentage, but actual calories burned for exercise is not dependent on how much or how little muscle mass you have. That only affects how hard it feels for you - not whether or not you're burning more calories. Thus the reason why things that just make your heart race (like scary movies and sex) are not nearly as high calorie burners as climbing stairs.

    The modality you use to cover a distance does make a difference in calories burned. It's true that walking a mile burns a similar number of calories per mile no matter how fast you walk, and running burns the same calories per mile no matter how fast you run (steady state), but running a mile will burn significantly more calories than walking a mile.
  • cmriverside
    cmriverside Posts: 34,451 Member
    ^^ Azdak knows his stuff, so I would try his way.


    I found that the Polar really wasn't all that much help when I had a lot to lose. Like Azdak says, the important thing is that you walked for 90 minutes. WELL DONE!!

    I would not worry so much about exact numbers if I were you, just walk.

    When you get closer to your goal weight, the Polar will be more helpful, as you will be in better fitness shape, cardiovascularly, and you will have a harder time losing weight. Right now, any exercise is beneficial, and it will be helping you get healthy - which is super important right now for you.

    Great job!
  • glittersoul
    glittersoul Posts: 666 Member
    I had the exact same problem with my FT7 and had to return it to amazon.

    http://www.myfitnesspal.com/topics/show/182246-low-calorie-burn-w-hrm
  • AshleighFTM
    AshleighFTM Posts: 18 Member
    What was your walking pace? It sounds to me like both your devices are off.

    According the the established energy prediction equations, you were walking at 2.0 mph and she was walking at around 5 mph.

    The equations can be a little off when you start getting up to heavier weights. That is because the energy costs of breathing and general locomotion are higher - normally these are not included in energy estimates.

    The best general way to estimate calories with walking (up to 4.0 mph) is just to multiply walking speed in miles per hour times your body weight in kg. That will give you calories per hour and you can multiply that by the total hours (or fraction of an hour) that you walk. That should be close enough.

    What is important and awesome is that you are walking for 90 minutes.

    Thanks Azdak!

    We walked 5.42 miles. If my math is correct roughly 3.61mph. I will still utilize my HRM but also give your equation a try.
  • Blackthorne99
    Blackthorne99 Posts: 250 Member

    The modality you use to cover a distance does make a difference in calories burned. It's true that walking a mile burns a similar number of calories per mile no matter how fast you walk, and running burns the same calories per mile no matter how fast you run (steady state), but running a mile will burn significantly more calories than walking a mile.

    Explain your reasoning, please. If you are moving 150lbs through space, why would running burn more than walking if you are traveling the same distance?

    If you look at most 'calories burned' charts, walking 3mph burns about 300 calories per hour (100 calories per mile) and running burns about 600 calories per hour (6mph pace) which is again 100 calories per mile.
  • Azdak
    Azdak Posts: 8,281 Member

    The modality you use to cover a distance does make a difference in calories burned. It's true that walking a mile burns a similar number of calories per mile no matter how fast you walk, and running burns the same calories per mile no matter how fast you run (steady state), but running a mile will burn significantly more calories than walking a mile.

    Explain your reasoning, please. If you are moving 150lbs through space, why would running burn more than walking if you are traveling the same distance?

    If you look at most 'calories burned' charts, walking 3mph burns about 300 calories per hour (100 calories per mile) and running burns about 600 calories per hour (6mph pace) which is again 100 calories per mile.

    It's not a question of "reasoning". The biomechanics of running are fundamentally different than walking. Don't know the source of your charts, but those numbers are not accurate. The physiology is simple and straightforward.

    For ease of arithmetic, let's use an 80kg (176lb) person:

    Walking 3.0 mph: Approx cals burned per hour: 240. Time to walk one mile: 20 min Cals burned per mile: 80
    Walking 4.0 mph: Approx cals burned per hour: 320. Time to walk one mile: 15 min. Cals/mile: 80

    Running 6.0 mph: Approx cals burned per hour: 800. Time to run one mile: 10 min. Cals/mile: 133
    Running 8.0 mph: Approx cals burned per hour: 1064 Time to run one mile: 7.5 min. Cals/mile: 133

    Calorie estimates are derived using the energy expenditure prediction equations published by the American College of Sports Medicine, which are the accepted standard for estimating such things.

    I know the "100 calories per mile" phrase has been around for decades--unfortunately it has never been accurate. I can only suppose it's use was started at a time when most people ran and so it wasn't considered important to make the distinction. I guess it depends on how you like to round your numbers. Theoretically, I suppose, both 80 calories per mile and 133 calories per mile could be considered "roughly 100 calories per mile", but I think it is a significant spread.
  • Blackthorne99
    Blackthorne99 Posts: 250 Member
    It's not a question of "reasoning". The biomechanics of running are fundamentally different than walking. Don't know the source of your charts, but those numbers are not accurate. The physiology is simple and straightforward.

    For ease of arithmetic, let's use an 80kg (176lb) person:

    Walking 3.0 mph: Approx cals burned per hour: 240. Time to walk one mile: 20 min Cals burned per mile: 80
    Walking 4.0 mph: Approx cals burned per hour: 320. Time to walk one mile: 15 min. Cals/mile: 80

    Running 6.0 mph: Approx cals burned per hour: 800. Time to run one mile: 10 min. Cals/mile: 133
    Running 8.0 mph: Approx cals burned per hour: 1064 Time to run one mile: 7.5 min. Cals/mile: 133

    Calorie estimates are derived using the energy expenditure prediction equations published by the American College of Sports Medicine, which are the accepted standard for estimating such things.

    I know the "100 calories per mile" phrase has been around for decades--unfortunately it has never been accurate. I can only suppose it's use was started at a time when most people ran and so it wasn't considered important to make the distinction. I guess it depends on how you like to round your numbers. Theoretically, I suppose, both 80 calories per mile and 133 calories per mile could be considered "roughly 100 calories per mile", but I think it is a significant spread.

    So what happens if you cover a mile at 5mph - does it differentiate between "fast walking" and "slow running" and if so - why? When you refer to the biomechanics of running vs. walking, what are you referring to? More arm swinging? Does running move you farther through space (because of the bouncing up and down)? Would a 176 lb person with no arms still burn 133 calories per mile?
  • Azdak
    Azdak Posts: 8,281 Member
    It's not a question of "reasoning". The biomechanics of running are fundamentally different than walking. Don't know the source of your charts, but those numbers are not accurate. The physiology is simple and straightforward.

    For ease of arithmetic, let's use an 80kg (176lb) person:

    Walking 3.0 mph: Approx cals burned per hour: 240. Time to walk one mile: 20 min Cals burned per mile: 80
    Walking 4.0 mph: Approx cals burned per hour: 320. Time to walk one mile: 15 min. Cals/mile: 80

    Running 6.0 mph: Approx cals burned per hour: 800. Time to run one mile: 10 min. Cals/mile: 133
    Running 8.0 mph: Approx cals burned per hour: 1064 Time to run one mile: 7.5 min. Cals/mile: 133

    Calorie estimates are derived using the energy expenditure prediction equations published by the American College of Sports Medicine, which are the accepted standard for estimating such things.

    I know the "100 calories per mile" phrase has been around for decades--unfortunately it has never been accurate. I can only suppose it's use was started at a time when most people ran and so it wasn't considered important to make the distinction. I guess it depends on how you like to round your numbers. Theoretically, I suppose, both 80 calories per mile and 133 calories per mile could be considered "roughly 100 calories per mile", but I think it is a significant spread.

    So what happens if you cover a mile at 5mph - does it differentiate between "fast walking" and "slow running" and if so - why? When you refer to the biomechanics of running vs. walking, what are you referring to? More arm swinging? Does running move you farther through space (because of the bouncing up and down)? Would a 176 lb person with no arms still burn 133 calories per mile?

    The definition of "walking" vs "running" is: walking has one foot in contact with the ground at all times during the stride; running is when both feet leave the ground. The speed is irrelevant--I seriously doubt whether the presence or absence of arms has ever been explored experimentally.

    The energy estimate equations are valid for walking speeds up to 4.2 mph, and for running speeds greater than 5.0 mph. Anything outside that range does not fit the equations because, at those speeds, there are too many variations in gait style to come up with an equation that will fit everyone. So, while there is a difference in energy expenditure between walking 5.0 mph and running 5.0 mph, the walking expenditure cannot be estimated using the standard equation.
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