Overestimating Exercise Calories?

Duck_Puddle

To estimate calories, you must know the actual intensity of the workload being performed (NOT the heart rate--the actual workload itself).

Some exercise activities--treadmill walking, for example--are simple, the actual workload is relatively easy to accurately measure, and the equations that estimate calories are also accurate. So, if you can input an actual speed and elevation into MFP, those calories should be accurate.

If an activity -- say stationary cycling--is listed, but with only general categories of intensity to choose from (easy, medium, hard), obviously, the estimates will be less accurate, since there is no exact definition of what they mean.

Lastly, many of the occupational and recreational activities listed in the database derive their energy estimates from general tables of activities, the accuracy of which range from OK to "random guess".

For more information on how activity database calories are derived, follow this link:

http://www.myfitnesspal.com/blog/Azdak/view/estimating-calories-activity-databases-198041

So I'm asking a totally legit question here-not trying to argue (as I read your profile and you clearly know your stuff).

I understand the concept of workload (I think) and that an accurate measure of the workload is the basis for the energy expenditure estimates (based on actual measurements in labs and such). My question is doesn't the amount of energy required to perform a certain workload vary based on fitness level (at least to some degree)? Won't a person without the aerobic capacity to perform a certain activity consume more energy to do it than a person who has the aerobic capacity to perform an activity o much greater intensity?


Perhaps I am swayed by personal experience. But when I started all this, I worked up a sweat walking a 25 minute mile. I now feel that a 22 minute mile is marginally more challenging than sitting in a chair. My HR reflects that fitness gain-and whatever hocus pocus my Garmin uses to calculate calories burned also reflects a lower number (I haven't change the weight or anything else-I really don't use it for calorie counting anyway). The workload is the same, but the amount of energy I am using to perform that activity is substantially lower (or so it seems). Doesn't that factor into calories burned or is it just aerobic fitness?

palmerar

Don't get too caught up in the numbers....everything is really just an estimate.

Azdak

To estimate calories, you must know the actual intensity of the workload being performed (NOT the heart rate--the actual workload itself).

Some exercise activities--treadmill walking, for example--are simple, the actual workload is relatively easy to accurately measure, and the equations that estimate calories are also accurate. So, if you can input an actual speed and elevation into MFP, those calories should be accurate.

If an activity -- say stationary cycling--is listed, but with only general categories of intensity to choose from (easy, medium, hard), obviously, the estimates will be less accurate, since there is no exact definition of what they mean.

Lastly, many of the occupational and recreational activities listed in the database derive their energy estimates from general tables of activities, the accuracy of which range from OK to "random guess".

For more information on how activity database calories are derived, follow this link:

http://www.myfitnesspal.com/blog/Azdak/view/estimating-calories-activity-databases-198041

So I'm asking a totally legit question here-not trying to argue (as I read your profile and you clearly know your stuff).

I understand the concept of workload (I think) and that an accurate measure of the workload is the basis for the energy expenditure estimates (based on actual measurements in labs and such). My question is doesn't the amount of energy required to perform a certain workload vary based on fitness level (at least to some degree)? Won't a person without the aerobic capacity to perform a certain activity consume more energy to do it than a person who has the aerobic capacity to perform an activity o much greater intensity?


Perhaps I am swayed by personal experience. But when I started all this, I worked up a sweat walking a 25 minute mile. I now feel that a 22 minute mile is marginally more challenging than sitting in a chair. My HR reflects that fitness gain-and whatever hocus pocus my Garmin uses to calculate calories burned also reflects a lower number (I haven't change the weight or anything else-I really don't use it for calorie counting anyway). The workload is the same, but the amount of energy I am using to perform that activity is substantially lower (or so it seems). Doesn't that factor into calories burned or is it just aerobic fitness?

Not really. HRMs have conditioned everyone to think of this backwards. We mistakenly accept the HRM numbers as the "standard" and judge everything based on how they relate to those numbers.

In general (and yes there are some variances, but not that significant), for simple, structured activities such as walking, running, elliptical, stairs, etc --activities that don't require high levels of coordination or motor skills--the aerobic cost of the activity is relatively fixed and is not dependent on fitness level--or age, height, or gender, for that matter.

I often use the example of running at 6 mph (10:00 mile) because the numbers are easy. The aerobic cost of running at that speed (level ground, no wind) is 10 METs (a MET is a measure of oxygen uptake). That cost of 10 METs is the same no matter who is doing the running--me, you, my stepson, an Olympic athlete, etc). It is the same for the same person after they have been running for 12 months. It is a relatively fixed cost.

The difference in perception is that the fixed cost of an aerobic activity will become a LOWER percentage of your maximum over time and with training. The cost is the same (10 METs), but if your aerobic maximum increases over time with training, it will now be a lower percentage of the max, and thus it will feel easier and your heart rate for running at that speed will be lower.

Your heart rate range is relatively fixed as well. When you train and increase your fitness level, your VO2 max (aerobic fitness) increases but your HR max (maximum heart rate does not). So when you start training, your VO2max might be 12 METs and HRmax is 180. With training, you might increase your VO2max to 15 METs, but HRmax will still be 180. The increase in VO2 max basically "resets" your heart rate/oxygen uptake "scale".

So where before, running 6.0 mph (i.e. working at 10 METs) might have represented 83% of your max and resulted in a heart rate of 160, now working at 10 METs now represents 67% of your maximum and result in a heart rate of 140. (Or, to look at it another way, now you can run 7 mph before you reach a heart rate of 160).

The reason why the HRM shows a lower calorie burn is that the HRM doesn't know your actual workload. And often the HRMs do not know your VO2 max. So the HRM is assuming (in this case) that your VO2 max is still 12 METs and the lower heart rate means you are working at a lower absolute intensity.

Hopefully, I have explained it well enough that you realize that the lower calorie burn on your HRM is due to the fact that your HRM settings have become outdated, NOT because you are burning fewer calories.

(Of course, if you have lost weight, then, yes, you will burn fewer calories at any given workload. From a weight loss standpoint, that should be offset somewhat by the fact that you can now run faster or exercise at a higher workload).

Hope that provides more background.

And BTW, please don't ever hesitate to ask a question--or even to argue. I keep my credentials in the background because I really don't want people to feel I am unapproachable. A good question--or even a good argument--can often make for a constructive and positive exchange. And---I don't know everything, so I am always happy to hear new information.

Duck_Puddle

To estimate calories, you must know the actual intensity of the workload being performed (NOT the heart rate--the actual workload itself).

Some exercise activities--treadmill walking, for example--are simple, the actual workload is relatively easy to accurately measure, and the equations that estimate calories are also accurate. So, if you can input an actual speed and elevation into MFP, those calories should be accurate.

If an activity -- say stationary cycling--is listed, but with only general categories of intensity to choose from (easy, medium, hard), obviously, the estimates will be less accurate, since there is no exact definition of what they mean.

Lastly, many of the occupational and recreational activities listed in the database derive their energy estimates from general tables of activities, the accuracy of which range from OK to "random guess".

For more information on how activity database calories are derived, follow this link:

http://www.myfitnesspal.com/blog/Azdak/view/estimating-calories-activity-databases-198041

So I'm asking a totally legit question here-not trying to argue (as I read your profile and you clearly know your stuff).

I understand the concept of workload (I think) and that an accurate measure of the workload is the basis for the energy expenditure estimates (based on actual measurements in labs and such). My question is doesn't the amount of energy required to perform a certain workload vary based on fitness level (at least to some degree)? Won't a person without the aerobic capacity to perform a certain activity consume more energy to do it than a person who has the aerobic capacity to perform an activity o much greater intensity?


Perhaps I am swayed by personal experience. But when I started all this, I worked up a sweat walking a 25 minute mile. I now feel that a 22 minute mile is marginally more challenging than sitting in a chair. My HR reflects that fitness gain-and whatever hocus pocus my Garmin uses to calculate calories burned also reflects a lower number (I haven't change the weight or anything else-I really don't use it for calorie counting anyway). The workload is the same, but the amount of energy I am using to perform that activity is substantially lower (or so it seems). Doesn't that factor into calories burned or is it just aerobic fitness?

Not really. HRMs have conditioned everyone to think of this backwards. We mistakenly accept the HRM numbers as the "standard" and judge everything based on how they relate to those numbers.

In general (and yes there are some variances, but not that significant), for simple, structured activities such as walking, running, elliptical, stairs, etc --activities that don't require high levels of coordination or motor skills--the aerobic cost of the activity is relatively fixed and is not dependent on fitness level--or age, height, or gender, for that matter.

I often use the example of running at 6 mph (10:00 mile) because the numbers are easy. The aerobic cost of running at that speed (level ground, no wind) is 10 METs (a MET is a measure of oxygen uptake). That cost of 10 METs is the same no matter who is doing the running--me, you, my stepson, an Olympic athlete, etc). It is the same for the same person after they have been running for 12 months. It is a relatively fixed cost.

The difference in perception is that the fixed cost of an aerobic activity will become a LOWER percentage of your maximum over time and with training. The cost is the same (10 METs), but if your aerobic maximum increases over time with training, it will now be a lower percentage of the max, and thus it will feel easier and your heart rate for running at that speed will be lower.

Your heart rate range is relatively fixed as well. When you train and increase your fitness level, your VO2 max (aerobic fitness) increases but your HR max (maximum heart rate does not). So when you start training, your VO2max might be 12 METs and HRmax is 180. With training, you might increase your VO2max to 15 METs, but HRmax will still be 180. The increase in VO2 max basically "resets" your heart rate/oxygen uptake "scale".

So where before, running 6.0 mph (i.e. working at 10 METs) might have represented 83% of your max and resulted in a heart rate of 160, now working at 10 METs now represents 67% of your maximum and result in a heart rate of 140. (Or, to look at it another way, now you can run 7 mph before you reach a heart rate of 160).

The reason why the HRM shows a lower calorie burn is that the HRM doesn't know your actual workload. And often the HRMs do not know your VO2 max. So the HRM is assuming (in this case) that your VO2 max is still 12 METs and the lower heart rate means you are working at a lower absolute intensity.

Hopefully, I have explained it well enough that you realize that the lower calorie burn on your HRM is due to the fact that your HRM settings have become outdated, NOT because you are burning fewer calories.

(Of course, if you have lost weight, then, yes, you will burn fewer calories at any given workload. From a weight loss standpoint, that should be offset somewhat by the fact that you can now run faster or exercise at a higher workload).

Hope that provides more background.

And BTW, please don't ever hesitate to ask a question--or even to argue. I keep my credentials in the background because I really don't want people to feel I am unapproachable. A good question--or even a good argument--can often make for a constructive and positive exchange. And---I don't know everything, so I am always happy to hear new information.

Thank you-that makes perfect sense and answers all my "follow up" questions. I'm not terribly worried about the calories burned myself (to some degree but all I do is run and since 87 calculators and mfp all say pretty much the same thing-I'm really calling it a wash). Your info explains everything (including why my fancy garmin does what it does). I've just seen you mention the workload a few times recently and I was curious about the rest. Makes perfect sense now-thank you!

jacksonpt

Not really. HRMs have conditioned everyone to think of this backwards. We mistakenly accept the HRM numbers as the "standard" and judge everything based on how they relate to those numbers.

In general (and yes there are some variances, but not that significant), for simple, structured activities such as walking, running, elliptical, stairs, etc --activities that don't require high levels of coordination or motor skills--the aerobic cost of the activity is relatively fixed and is not dependent on fitness level--or age, height, or gender, for that matter.

I often use the example of running at 6 mph (10:00 mile) because the numbers are easy. The aerobic cost of running at that speed (level ground, no wind) is 10 METs (a MET is a measure of oxygen uptake). That cost of 10 METs is the same no matter who is doing the running--me, you, my stepson, an Olympic athlete, etc). It is the same for the same person after they have been running for 12 months. It is a relatively fixed cost.

The difference in perception is that the fixed cost of an aerobic activity will become a LOWER percentage of your maximum over time and with training. The cost is the same (10 METs), but if your aerobic maximum increases over time with training, it will now be a lower percentage of the max, and thus it will feel easier and your heart rate for running at that speed will be lower.

Your heart rate range is relatively fixed as well. When you train and increase your fitness level, your VO2 max (aerobic fitness) increases but your HR max (maximum heart rate does not). So when you start training, your VO2max might be 12 METs and HRmax is 180. With training, you might increase your VO2max to 15 METs, but HRmax will still be 180. The increase in VO2 max basically "resets" your heart rate/oxygen uptake "scale".

So where before, running 6.0 mph (i.e. working at 10 METs) might have represented 83% of your max and resulted in a heart rate of 160, now working at 10 METs now represents 67% of your maximum and result in a heart rate of 140. (Or, to look at it another way, now you can run 7 mph before you reach a heart rate of 160).

The reason why the HRM shows a lower calorie burn is that the HRM doesn't know your actual workload. And often the HRMs do not know your VO2 max. So the HRM is assuming (in this case) that your VO2 max is still 12 METs and the lower heart rate means you are working at a lower absolute intensity.

Hopefully, I have explained it well enough that you realize that the lower calorie burn on your HRM is due to the fact that your HRM settings have become outdated, NOT because you are burning fewer calories.

(Of course, if you have lost weight, then, yes, you will burn fewer calories at any given workload. From a weight loss standpoint, that should be offset somewhat by the fact that you can now run faster or exercise at a higher workload).

Hope that provides more background.

And BTW, please don't ever hesitate to ask a question--or even to argue. I keep my credentials in the background because I really don't want people to feel I am unapproachable. A good question--or even a good argument--can often make for a constructive and positive exchange. And---I don't know everything, so I am always happy to hear new information.

great stuff, as always.

dym123

When I got an HRM, I compared it to MFP and to Everyday Health, which is where I got my Turbo Fire estimates. I found MFP actually does overestimate, Everyday Health underestimated.

Edited to add: MFP & EH doesn't really take into account when you become used to a workout. Last night while doing a workout that used to kill me, but I got through it effortlessly without stopping, yeah I broke a serious sweat, but I wasn't as out of breath like I used to be.

rachaelgifford

I am never 100% accurate with my calorie counting, and my HRM is probably not 100% accurate at measuring calories burned. I figure that having a close idea is better than where I was before I started here. I personally go for the lowest calorie burned option, be it my HRM (which it usually is) or MFP, and if I am not sure about the food, I go for a higher calorie value in the option. I guess it kind of evens out. When I am closer to my goal, I will have to be more careful, but right now it is working and it is part of my life, but not controlling it :-)

cwolfman13

What you have to remember is that MFP's estimates are just some burn from some other person's workout...no body has the same burn...much depends on: 1.) intensity, 2.) your fitness level, 3.) heigh/weight/age, 4.) possible medical issues and the list goes on and on.

A HRM is a good investment if you want a more accurate calorie count and invaluable if you want to learn to train in appropriate zones to meet your goals. If you use a HRM, remember to deduct the calories based on your BMR for that period of time that would have been burned regardless of your exercise.

imhungry2012

[/quote]

Not really. HRMs have conditioned everyone to think of this backwards. We mistakenly accept the HRM numbers as the "standard" and judge everything based on how they relate to those numbers.

In general (and yes there are some variances, but not that significant), for simple, structured activities such as walking, running, elliptical, stairs, etc --activities that don't require high levels of coordination or motor skills--the aerobic cost of the activity is relatively fixed and is not dependent on fitness level--or age, height, or gender, for that matter.

I often use the example of running at 6 mph (10:00 mile) because the numbers are easy. The aerobic cost of running at that speed (level ground, no wind) is 10 METs (a MET is a measure of oxygen uptake). That cost of 10 METs is the same no matter who is doing the running--me, you, my stepson, an Olympic athlete, etc). It is the same for the same person after they have been running for 12 months. It is a relatively fixed cost.

The difference in perception is that the fixed cost of an aerobic activity will become a LOWER percentage of your maximum over time and with training. The cost is the same (10 METs), but if your aerobic maximum increases over time with training, it will now be a lower percentage of the max, and thus it will feel easier and your heart rate for running at that speed will be lower.

Your heart rate range is relatively fixed as well. When you train and increase your fitness level, your VO2 max (aerobic fitness) increases but your HR max (maximum heart rate does not). So when you start training, your VO2max might be 12 METs and HRmax is 180. With training, you might increase your VO2max to 15 METs, but HRmax will still be 180. The increase in VO2 max basically "resets" your heart rate/oxygen uptake "scale".

So where before, running 6.0 mph (i.e. working at 10 METs) might have represented 83% of your max and resulted in a heart rate of 160, now working at 10 METs now represents 67% of your maximum and result in a heart rate of 140. (Or, to look at it another way, now you can run 7 mph before you reach a heart rate of 160).

The reason why the HRM shows a lower calorie burn is that the HRM doesn't know your actual workload. And often the HRMs do not know your VO2 max. So the HRM is assuming (in this case) that your VO2 max is still 12 METs and the lower heart rate means you are working at a lower absolute intensity.

Hopefully, I have explained it well enough that you realize that the lower calorie burn on your HRM is due to the fact that your HRM settings have become outdated, NOT because you are burning fewer calories.

(Of course, if you have lost weight, then, yes, you will burn fewer calories at any given workload. From a weight loss standpoint, that should be offset somewhat by the fact that you can now run faster or exercise at a higher workload).

Hope that provides more background.

And BTW, please don't ever hesitate to ask a question--or even to argue. I keep my credentials in the background because I really don't want people to feel I am unapproachable. A good question--or even a good argument--can often make for a constructive and positive exchange. And---I don't know everything, so I am always happy to hear new information.
[/quote]

I have been trying to get this kind of info - i was wondering if as I became more fit if the same exercise (jogging 6.0 for example) for the same amount of time was burning LESS calories than it was when I was less fit, sounds like no, yay! Thanks!

eclarso

Thanks for all the info everyone! Very helpful!