Fit Bands or HRM

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  • jim180155
    jim180155 Posts: 769 Member
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    I see, so basically what you're saying is that there is no direct correlation between your heart rate and calorie burn. I get the science stuff. A calorie is a unit of energy (of heat), and the work to move an object of mass is uniform.

    So essentially if you took the same 230lb people.. Both of the same height. But one is 12% BMI and conditioned for running,.. and the other 33% and in no condition to speak of,.. Started them at a line and told them both to run a specified distance and a specified speed (so they're running side by side).. You will concede that the 33% guy's heart is going to be thumping faster than the other guy's when they cross the finish line.. But he's burned no more calories than the other guy even though his heart rate didn't even get into cardio range..

    Do I have that right?

    Yes, you have that right.

    How about this: Two guys have to push a load on a four wheel cart up a hill. The load for both guys is 1,000 pounds. Both guys weigh the same and are of identical height. Both guys are wearing the same type of shoes. Both carts are the same with handles at the same height. The only difference is that the first guy is pushing a cart loaded with a 1,000 pound block of solid steel while the second guy is pushing a 1,000 pound blob of Jello.

    Both guys will burn identical calories getting their carts up the hill.
  • ryangassxx
    ryangassxx Posts: 12
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    I'll be honest I'm just having a very difficult time drawing the parallels. Intuitively, everything that I know about exercise is saying that none of that makes any sense. I could very well be completely wrong, but I just can't reconcile what you're saying. And don't get me wrong I completely get what you're saying. I just think there must be some critical element that isn't being accounted for in your analogies, and I suspect it's the point of where you're measuring energy.. Calories are burning heat units. I believe a less conditioned man will generate more units of heat to do the same work externally. Measuring the external work is going to be uniform. This is why we don't simply use "reps" as a standard measurement of how much of a workout you've gotten, and it's why someone who works out will gradually increase rep counts over time as they become more conditioned. If what you're saying is true, why would anyone ever increase workout reps over time if the exercise benefit of doing the same reps stays consistent? They're just moving energy right?
  • heybales
    heybales Posts: 18,842 Member
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    I see, so basically what you're saying is that there is no direct correlation between your heart rate and calorie burn. I get the science stuff. A calorie is a unit of energy (of heat), and the work to move an object of mass is uniform.

    So essentially if you took the same 230lb people.. Both of the same height. But one is 12% BMI and conditioned for running,.. and the other 33% and in no condition to speak of,.. Started them at a line and told them both to run a specified distance and a specified speed (so they're running side by side).. You will concede that the 33% guy's heart is going to be thumping faster than the other guy's when they cross the finish line.. But he's burned no more calories than the other guy even though his heart rate didn't even get into cardio range..

    Do I have that right?

    There is no direct correlation - there is a lose association. Which is the best your get outside wearing a backpack air bag and face mask to collect what you breath, and measure it later.

    Now - my whole discussions above were about running and walking, those formula's are more accurate than HRM's.
    Formula's for cycle-ergometers are more accurate too, if you use cadence, and watts, ect, and are sitting.
    Rowing on machine is equally good, watts known, and pull rate, ect.

    But almost everything else, even ellipticals with so many variables, have no valid formula's. All that stuff is going to be best with HRM.

    Your example of running is correct. And the high HR guy is burning probably almost total carbs, so he'd run out faster. Fit guy is burning much more fat and carbs and could go longer.

    Now as you mention on HR thumping along at 2 very different levels. Here's why the cheaper HRM's including Polar lose out on accuracy. They all need a VO2max stat to even estimate calorie burn. But some don't have a visible stat, they estimate it.

    So the cheaper ones calculate your BMI (height and weight) and see where it is in range of good to bad (age and gender). Now you know why they need those stats. Age is also use for 220-age = HRmax (another big assumption).

    So your 2 guys with same everything, but one more fit and muscular.
    His HR is low. HRM sees perhaps bad BMI, so assumes bad fitness and VO2max, so low HR means low calorie burn.

    Other guy with high HR, HRM figures high HR means higher calorie burn.

    So a HRM on both would be very different figures. But get a HRM with tested VO2max stats in them, and they'd be about the same.

    And it's much faster to get fit than lose weight. So all these folks with cheaper Polar's that get fit faster than they lose weight, are actually getting under-reported calorie burns. Except the inaccuracy may have that even out. Difficult to know.

    Page 2 of this topic, my post on results testing 2 Polar's, one with no VO2max stat, one with it, compared to an actual VO2max test.
    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn
  • ryangassxx
    ryangassxx Posts: 12
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    I see, so basically what you're saying is that there is no direct correlation between your heart rate and calorie burn. I get the science stuff. A calorie is a unit of energy (of heat), and the work to move an object of mass is uniform.

    So essentially if you took the same 230lb people.. Both of the same height. But one is 12% BMI and conditioned for running,.. and the other 33% and in no condition to speak of,.. Started them at a line and told them both to run a specified distance and a specified speed (so they're running side by side).. You will concede that the 33% guy's heart is going to be thumping faster than the other guy's when they cross the finish line.. But he's burned no more calories than the other guy even though his heart rate didn't even get into cardio range..

    Do I have that right?

    There is no direct correlation - there is a lose association. Which is the best your get outside wearing a backpack air bag and face mask to collect what you breath, and measure it later.

    Now - my whole discussions above were about running and walking, those formula's are more accurate than HRM's.
    Formula's for cycle-ergometers are more accurate too, if you use cadence, and watts, ect, and are sitting.
    Rowing on machine is equally good, watts known, and pull rate, ect.

    But almost everything else, even ellipticals with so many variables, have no valid formula's. All that stuff is going to be best with HRM.

    Your example of running is correct. And the high HR guy is burning probably almost total carbs, so he'd run out faster. Fit guy is burning much more fat and carbs and could go longer.

    Now as you mention on HR thumping along at 2 very different levels. Here's why the cheaper HRM's including Polar lose out on accuracy. They all need a VO2max stat to even estimate calorie burn. But some don't have a visible stat, they estimate it.

    So the cheaper ones calculate your BMI (height and weight) and see where it is in range of good to bad (age and gender). Now you know why they need those stats. Age is also use for 220-age = HRmax (another big assumption).

    So your 2 guys with same everything, but one more fit and muscular.
    His HR is low. HRM sees perhaps bad BMI, so assumes bad fitness and VO2max, so low HR means low calorie burn.

    Other guy with high HR, HRM figures high HR means higher calorie burn.

    So a HRM on both would be very different figures. But get a HRM with tested VO2max stats in them, and they'd be about the same.

    And it's much faster to get fit than lose weight. So all these folks with cheaper Polar's that get fit faster than they lose weight, are actually getting under-reported calorie burns. Except the inaccuracy may have that even out. Difficult to know.

    Page 2 of this topic, my post on results testing 2 Polar's, one with no VO2max stat, one with it, compared to an actual VO2max test.
    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn

    Alright I concede, solely because you seem to know what you're talking about :P , I'm just having a difficult time wrapping my head around it. It was always my impression that heart rate was a direct indicator to the amount of work your body was doing, and at the very least a HRM had some means of sampling your biology in order to form something to predicate it's calorie burn calculations on. Motion sensing devices have no means of biology sampling. But evidently there is some very high level technical stuff at play that I am not aware of that goes way over my head, and that's good enough for me.

    Go science!
  • heybales
    heybales Posts: 18,842 Member
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    I'll be honest I'm just having a very difficult time drawing the parallels. Intuitively, everything that I know about exercise is saying that none of that makes any sense. I could very well be completely wrong, but I just can't reconcile what you're saying. And don't get me wrong I completely get what you're saying. I just think there must be some critical element that isn't being accounted for in your analogies, and I suspect it's the point of where you're measuring energy.. Calories are burning heat units. I believe a less conditioned man will generate more units of heat to do the same work externally. Measuring the external work is going to be uniform. This is why we don't simply use "reps" as a standard measurement of how much of a workout you've gotten, and it's why someone who works out will gradually increase rep counts over time as they become more conditioned. If what you're saying is true, why would anyone ever increase workout reps over time if the exercise benefit of doing the same reps stays consistent? They're just moving energy right?

    Did you read the study in the prior link about running and walking calorie burn. Go read the details of the study for the weight ranges and gender and age. All over the board.

    So for reps then, equal weight, same length of arms so same lever being applied.
    Strong man can do 20 lbs easy, barely engaging his muscles to do curls.
    Weak man can barely do it, producing a lot of heat of effort and total muscle engagement.

    Same energy used to accomplish by both men.

    When you start diverging is the variable in real life. Like even those formula for walking/running calorie burns. Notice level.
    Up to certain incline still good.
    But get too steep, now personal differences make it a different effort and different burn.
    Like longer stride than normal up a hill means more effort to lift that weight higher, shorter stride means less energy. Shoot, shorter legs trying to lop along outside comfort zone is more energy.

    And even the HR example, with same VO2max tested, so same fitness level. One may have genetically lower HRmax and one higher, so their HR at same given level could be very different, and yet burning same calories.
    Some have diesel hearts, some Honda hearts.
  • heybales
    heybales Posts: 18,842 Member
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    Page 2 of this topic, my post on results testing 2 Polar's, one with no VO2max stat, one with it, compared to an actual VO2max test.
    http://www.myfitnesspal.com/topics/show/773451-is-my-hrm-giving-me-incorrect-calorie-burn

    Alright I concede, solely because you seem to know what you're talking about :P , I'm just having a difficult time wrapping my head around it. It was always my impression that heart rate was a direct indicator to the amount of work your body was doing, and at the very least a HRM had some means of sampling your biology in order to form something to predicate it's calorie burn calculations on. Motion sensing devices have no means of biology sampling. But evidently there is some very high level technical stuff at play that I am not aware of that goes way over my head, and that's good enough for me.

    Go science!

    Read the first post of above topic before going to page 2.
    It talks about all the other reasons your HR can be inflated and nothing about your current workload.

    So you could run exact same run, 2 days in a row. And be dehydrated the 2nd run, and HR is inflated by 5-10 bpm.
    Does that mean more effort that resulted in bigger calorie burn?
    No, bigger effort by heart to move thick blood around to get the oxygen it needs, yes. But not because you needed more oxygen.

    Or had double-expresso with energy drink prior to workout, and HR is inflated by 10-15 bpm. Same effort as day before. Heart isn't beating faster because body needs more oxygen because of bigger calorie burn - it's hopped up because of drugs basically.

    If you want to read up more on the science beyond my posts, here's another.
    http://www.myfitnesspal.com/topics/show/1044313-this-is-why-hrms-have-limited-use-for-tracking-calories
  • ryangassxx
    ryangassxx Posts: 12
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    I'll dive into it when I have more time.

    I'm sold though on what you're saying.

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