Are treadmill calorie counters correct?
committomittxoxo
Posts: 339 Member
YooHoo... Question!! Maybe for all the trainers out there?!
I love to run.. especially on the treadmill. But are the 'calories lost' calculators on treadmills accurate? I always assumed they were high ballin it a bit.. but I thought my buddy Dolvett on 'Biggest Loser' said they're pretty close? I am confused.. anybody able to shine some light on this?
Thanks friends..
Cheers!
I love to run.. especially on the treadmill. But are the 'calories lost' calculators on treadmills accurate? I always assumed they were high ballin it a bit.. but I thought my buddy Dolvett on 'Biggest Loser' said they're pretty close? I am confused.. anybody able to shine some light on this?
Thanks friends..
Cheers!
0
Replies
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I run outside (a bunch), at 175 lbs, I burn ~ 125 calories per mile. If I hustle I can burn ~ 1,000 in an hour. That is my reality check. Clicking off 7:30 miles for an hour takes a decent chunk of effort. So anything that is indicating that type of burn best be at a high level of effort.
FWIW - I find the MFP database to be pretty accurate for running (but not much else)0 -
Well if you set your weight, height on the treadmill before starting, it's closer to the right number of calories burned otherwise it's quite inflated. I invested in heart rate monitor and it was such a good investment.0
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I"m not sure about the ones at the gym but the one my dad got for our home I am sure is way off, I'm sure I'm not burning 100 calories walking a mile at my normal spead exspecially when I did that every day for four years of high school.0
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Well if you set your weight, height on the treadmill before starting, it's closer to the right number of calories burned otherwise it's quite inflated.
Very true. Make sure you customize it otherwise it defaults to the average person or some random number. The treadmill at the gym (without entering myheight and weight) says I burn 320(ish) calories in 3 miles at a 10 min mile pace when in actuality I only burn about 230. HUGE difference0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
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edit-- even when you enter in your weight.. heart rate is a crucial determinant.0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
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edit-- even when you enter in your weight.. heart rate is a crucial determinant.
You could be right!! Most people dont even hold on to the sensor on the Treadmill to monitor their HR and your HR makes a differnce in calorie burn..... IMO0 -
Thanks guys!
Thank you for clearing that up.. got stuck in a little debate with my loving mother.. turns out we were both sort of right. I'll take the credit for it though. lol.
Cheers!
:drinker:0 -
So if the treadmill has a hear-rate analyzer that you grab onto, is it still inflating the calories burned?
I spent an hour on the treadmill doing moderate-pace walking and fooling around with different inclines - mostly a gentle grade - and it said I burned about 225 calories and walked roughly two miles. I used the heart rate monitor for most of the walk. I think that sounds mostly right. But I don't want to get too reliant on what it says if it's just telling me I burned more than I actually did!0 -
So if the treadmill has a hear-rate analyzer that you grab onto, is it still inflating the calories burned?
I spent an hour on the treadmill doing moderate-pace walking and fooling around with different inclines - mostly a gentle grade - and it said I burned about 225 calories and walked roughly two miles. I used the heart rate monitor for most of the walk. I think that sounds mostly right. But I don't want to get too reliant on what it says if it's just telling me I burned more than I actually did!
Well, I highly, highly doubt the treadmill takes into account heart rate when estimating calorie expenditure. Some inidviduals do not test their HR at all, some once, and some keep tabs on it during the entirety of their workout. I just dont think the machines have the algorithms to complete the calculations. I would still highly recommend getting a HR monitor. It is really a small investment for what is provides. Feel free to message me for more questions! 0 -
I did a comparision with the treadmill calorie counter and my FT4. The treadmill was way off. I even set my weight, and age on the treadmil. The whole time I have been using the machines calorie counters I thought I was burning up some calories, but come to find out I was SO WRONG! How depressing! that explains alot. I ordered the FITBIT soon I am going to have this down to a science.
Maybe you could borrow someone's Heart Rate Monitor and give it a try. Check it out yourself. Best of luck to you! :drinker:0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
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edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.0 -
I just take whatever the treadmill tells me I've burnt and cut it into half or less, cause I assume it is wrong0
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So if the treadmill has a hear-rate analyzer that you grab onto, is it still inflating the calories burned?
I spent an hour on the treadmill doing moderate-pace walking and fooling around with different inclines - mostly a gentle grade - and it said I burned about 225 calories and walked roughly two miles. I used the heart rate monitor for most of the walk. I think that sounds mostly right. But I don't want to get too reliant on what it says if it's just telling me I burned more than I actually did!
Unless you hold on to the handrails, and as long as you can enter your weight, the calorie estimates on treadmills should be very accurate for walking--more accurate than an HRM. Running is a little different on a treadmill, because there is no wind resistance and more of a "bounding" action of the cushioned deck. So the calorie number are probably off by about 15% (too high).0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
I don't understand...0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
Heart Rate is INCREDIBLY relevant. Someone who is in great shape will not burn as many calories doing the same activity (walking) as someone in poor shape (Given they are same weight).. Heart rate, however, solves this problem. Don't get me wrong, weight does figure in.. but it is critically necessary to determine how hard your heart is working to estimate how many calories you are burning.0 -
If you can not put your weight in then it will not be correct, the average tread mill is set for a 150 pound male0
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It's important to realize that both treadmill calorie counts and HRM calorie counts are estimates, and should be treated as such. Wayyyy to much emphasis is put into HRMs on this site, as if their calorie readings are the gospel.
Heart rate is not the only factor that determines calorie loss. Several other factors determine how much energy you burn during an exercise. You could have the same heart rate on two different exercises but burn very different calorie counts, but the HRM will not account for that.
As one of the other posters said, how many calories your body burns while walking/running is pretty well established, so a properly calibrated treadmill should be pretty accurate in that regard. I would love to see a study where HRM and treadmill estimates are compared to the actual number of calories burned, and to see which is more accurate. My money would be on the treadmill.
HRMs are useful for activities that aren't in controlled environment. It's the only way to get a decent estimate for your Zumba class. But machine estimates on exercises that are done at a consistent pace are fairly accurate.
Also, as a sidenote, I don't believe the Heart Rate monitor on machines actually affects the calorie count. I think it's just for informational purposes only.0 -
It's important to realize that both treadmill calorie counts and HRM calorie counts are estimates, and should be treated as such. Wayyyy to much emphasis is put into HRMs on this site, as if their calorie readings are the gospel.
Heart rate is not the only factor that determines calorie loss. Several other factors determine how much energy you burn during an exercise. You could have the same heart rate on two different exercises but burn very different calorie counts, but the HRM will not account for that.
As one of the other posters said, how many calories your body burns while walking/running is pretty well established, so a properly calibrated treadmill should be pretty accurate in that regard. I would love to see a study where HRM and treadmill estimates are compared to the actual number of calories burned, and to see which is more accurate. My money would be on the treadmill.
HRMs are useful for activities that aren't in controlled environment. It's the only way to get a decent estimate for your Zumba class. But machine estimates on exercises that are done at a consistent pace are fairly accurate.
Also, as a sidenote, I don't believe the Heart Rate monitor on machines actually affects the calorie count. I think it's just for informational purposes only.
Seriously? A "controlled" environment has nothing to do with it. Clealy, HR isn't the only variable.. however, Heart Rate Monitors, which take your weight and gender into account are typically 90-95 percent accurate. Treadmills are a "one size fits all" device. They do not take into account your Heart Rate- which means they do not take into your account your fitness level. Really shocked that this is even debatable.0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
Heart Rate is INCREDIBLY relevant. Someone who is in great shape will not burn as many calories doing the same activity (walking) as someone in poor shape (Given they are same weight).. Heart rate, however, solves this problem. Don't get me wrong, weight does figure in.. but it is critically necessary to determine how hard your heart is working to estimate how many calories you are burning.
No it is not. A fit person running 6.0 mph will burn the same number of calories as a lower fit person of the same weight running at 6.0 mph. It will feel easier for the more fit person, but that's because their maximum fitness level is higher, and so the cost of running 6.0 mph represents a smaller percentage of their maximum. But the energy cost of running is essentially the same (about 10 METs), no matter who is doing it.
The only time heart rate is relevant is when someone is performing an activity that has different movements and intensities and therefore does not have a fixed energy cost. The only reason you need heart rate in that case is because that really is the only performance variable you have available. Even then, it is a very indirect way of estimating calories and has a fairly large error factor.
Simple aerobic activities such as walking, running, cycle ergometry (stationary bike that can measure watts or power meter on a road bike), stairclimbing--these have been researched in detail and there are well-established metabolic equations developed by the American College of Sports Medicine to predict oxygen uptake (and thus calories burned) at various intensity levels. None of these equations use heart rate as a variable--nor do they use fitness level.
The reason why so many people emphasize heart rate to estimate calories is that the use (and misuse) of HRMs has become so ingrained in the popular fitness culture. Yet very few people understand how these devices work, the underlying physiological processes behind the algorithms, or their limitations. As a result, people continuously make faulty assumptions about the nature of exercise based on the information they get from their HRMs. Even many personal trainers--who should know better--make these faulty assumptions and thus validate the misinformation.
I have written several blogs on the subject. This one is the most germane, and has links to the original one that contains the most basic information:
http://www.myfitnesspal.com/blog/Azdak/view/calories-burned-during-exercise-it-s-the-intensity-not-the-heart-rate-that-counts-265240 -
It's important to realize that both treadmill calorie counts and HRM calorie counts are estimates, and should be treated as such. Wayyyy to much emphasis is put into HRMs on this site, as if their calorie readings are the gospel.
Heart rate is not the only factor that determines calorie loss. Several other factors determine how much energy you burn during an exercise. You could have the same heart rate on two different exercises but burn very different calorie counts, but the HRM will not account for that.
As one of the other posters said, how many calories your body burns while walking/running is pretty well established, so a properly calibrated treadmill should be pretty accurate in that regard. I would love to see a study where HRM and treadmill estimates are compared to the actual number of calories burned, and to see which is more accurate. My money would be on the treadmill.
HRMs are useful for activities that aren't in controlled environment. It's the only way to get a decent estimate for your Zumba class. But machine estimates on exercises that are done at a consistent pace are fairly accurate.
Also, as a sidenote, I don't believe the Heart Rate monitor on machines actually affects the calorie count. I think it's just for informational purposes only.
I have seen a few studies that tried to compare HRM readings with actual measured oxygen uptake, but there are not that many out there. To be honest, it's not really seen as a serious subject among exercise physiologists. They see HRM calorie counts more as toys than anything else.0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
I don't understand...
Your calorie expenditure depends on how much oxygen your body uses. During aerobic activity, the need for oxygen increases, therefore the heart beats faster to deliver more blood to the working tissues so that oxygen can be extracted.
For simple aerobic movements, such as walking or running, there is a relatively fixed energy cost for any workout intensity. For example, walking at 3.0 mph on level ground requires about 10.5 ml of oxygen per kg of body wt per minute (ml/kg/min). Unless you are really short or really tall or really obese, that energy cost of 10.5 ml/kg/min is the same for everyone. For walking 4.0 mph, the cost is about 14 ml/kg/min, running 6.0 mph is about 35 ml/kg/min, and so on. We burn a fixed number of calories for every milliliter of O2 consumed, so knowing the energy cost makes it simple to estimate calorie burn with good accuracy.
You'll note that I haven't mentioned heart rate yet. That's because if we know the oxygen cost of the activity, then heart rate is irrelevant. Walking and running are simple activities--they have been well researched and the oxygen cost (and therefore the calories burn) of any combination and speed and elevation can be easily estimated using established equations. So, we don't need heart rate, or gender, or fitness level or anything else except weight (heavier bodies burn more calories than lighter ones).
Where heart rate becomes necessary is when we perform aerobic exercise movements that are not simple, not continuous, or do not have consistent established movements common to all individuals. For these activities, there are no established equations for estimating oxygen uptake.
However, during steady-state aerobic exercise, there is a consistent relationship between heart rate and oxygen uptake. Changes in oxygen uptake are accompanied by predictable changes in heart rate. For example we know that a heart rate of 70% of one's maximum heart rate corresponds to about 57% of maximal oxygen uptake (VO2max). If we know that a persons max heart rate is 180 beats/min and their VO2max is 40 ml/kg/min and they are working at a heart rate of 126 (70% of maximum), it means their oxygen uptake is about 23 ml/kg/min (57% of the VO2max of 40). From that 23 ml/kg/min, we can estimate calorie expenditure.
That, in essence, is how HRMs work. They develop algorithms based on the relationship of heart rate to oxygen uptake and then validate them by comparing the predicted calorie burn from the HRM to the actual measured calorie burn for the same activity. The nature of math is such (and I can't explain it any better because I am not a math expert) and including more variables--height, gender, age, along with weight--increases the accuracy of the HRM's algorithms, so that's why they include these extra variables.
Right away, you can see two things that will affect the accuracy of HRM calorie estimates: if you are estimating maximum heart rate and you are estimating maximum oxygen uptake, then overall accuracy of the HRM will be affected. Not everyone is able to get these numbers, which is why HRMs are probably only about 80% accurate under the best of conditions.
You can also see that if your VO2 max increases over time with training, but the HRM settings aren't updated, you will see a decrease in your calorie numbers. That's because your heart rate has decreased for the same workload--it has decreased because your maximum has INCREASED--now the work level (that 14 ml/kg/min example from before) represents a lower percentage of your maximum. The display suggests you are burning fewer calories, but in fact it's just your setup information that is outdated.
Lastly, HRM algorithms are only accurate when an increase in heart rate is accompanied by an increase in oxygen uptake--i.e. during steady-state cardio exercise.
Any condition or activity that causes heart rate to increase WITHOUT and increase in oxygen uptake will result in a bogus calorie number. That is why HRMs calorie readings for activities such as weight lifting and bikram yoga are useless--heart rate increases, but oxygen uptake does not. The HRM doesn 't know the difference.
Hopefully this helps--you can go to my profile and my blogs and find several articles that address these issues.0 -
Deleted because the post above was more coherent.0
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It depends, the treadmill at the gym says only about half that my HRM says, and I go with the HRM.. but you cannot enter your weight in.
A HRM is your best bet imho. 0 -
the treadmill for always says that I have burnt more than I actually have, Honestly the best option is to get a HRM and there are many cheap options out there. the best bang for your buck is the Polar ft40
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bump0
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Azdak, do you have any comments of LifeFitness ellipticals (or any ellipticals)? With a treadmill, you can set your speed and incline and then change either the speed or the incline manually as you go along. But with the LifeFitness elliptical, it seem that you need a heart rate because the machine will vary the resistance to maintain your heart rate at a certain (narrow) range. This means that the resistance changes constantly. Do you think the calories count of ellpiticals are accurate?0
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My calorie counter on my Pro-Form Performance 600 is actually pretty darn close, as compared to my Heart Rate Monitor. But it must be luck since the treadmill does not know how much I weigh...0
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No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
I don't understand...
Your calorie expenditure depends on how much oxygen your body uses. During aerobic activity, the need for oxygen increases, therefore the heart beats faster to deliver more blood to the working tissues so that oxygen can be extracted.
For simple aerobic movements, such as walking or running, there is a relatively fixed energy cost for any workout intensity. For example, walking at 3.0 mph on level ground requires about 10.5 ml of oxygen per kg of body wt per minute (ml/kg/min). Unless you are really short or really tall or really obese, that energy cost of 10.5 ml/kg/min is the same for everyone. For walking 4.0 mph, the cost is about 14 ml/kg/min, running 6.0 mph is about 35 ml/kg/min, and so on. We burn a fixed number of calories for every milliliter of O2 consumed, so knowing the energy cost makes it simple to estimate calorie burn with good accuracy.
You'll note that I haven't mentioned heart rate yet. That's because if we know the oxygen cost of the activity, then heart rate is irrelevant. Walking and running are simple activities--they have been well researched and the oxygen cost (and therefore the calories burn) of any combination and speed and elevation can be easily estimated using established equations. So, we don't need heart rate, or gender, or fitness level or anything else except weight (heavier bodies burn more calories than lighter ones).
Where heart rate becomes necessary is when we perform aerobic exercise movements that are not simple, not continuous, or do not have consistent established movements common to all individuals. For these activities, there are no established equations for estimating oxygen uptake.
However, during steady-state aerobic exercise, there is a consistent relationship between heart rate and oxygen uptake. Changes in oxygen uptake are accompanied by predictable changes in heart rate. For example we know that a heart rate of 70% of one's maximum heart rate corresponds to about 57% of maximal oxygen uptake (VO2max). If we know that a persons max heart rate is 180 beats/min and their VO2max is 40 ml/kg/min and they are working at a heart rate of 126 (70% of maximum), it means their oxygen uptake is about 23 ml/kg/min (57% of the VO2max of 40). From that 23 ml/kg/min, we can estimate calorie expenditure.
That, in essence, is how HRMs work. They develop algorithms based on the relationship of heart rate to oxygen uptake and then validate them by comparing the predicted calorie burn from the HRM to the actual measured calorie burn for the same activity. The nature of math is such (and I can't explain it any better because I am not a math expert) and including more variables--height, gender, age, along with weight--increases the accuracy of the HRM's algorithms, so that's why they include these extra variables.
Right away, you can see two things that will affect the accuracy of HRM calorie estimates: if you are estimating maximum heart rate and you are estimating maximum oxygen uptake, then overall accuracy of the HRM will be affected. Not everyone is able to get these numbers, which is why HRMs are probably only about 80% accurate under the best of conditions.
You can also see that if your VO2 max increases over time with training, but the HRM settings aren't updated, you will see a decrease in your calorie numbers. That's because your heart rate has decreased for the same workload--it has decreased because your maximum has INCREASED--now the work level (that 14 ml/kg/min example from before) represents a lower percentage of your maximum. The display suggests you are burning fewer calories, but in fact it's just your setup information that is outdated.
Lastly, HRM algorithms are only accurate when an increase in heart rate is accompanied by an increase in oxygen uptake--i.e. during steady-state cardio exercise.
Any condition or activity that causes heart rate to increase WITHOUT and increase in oxygen uptake will result in a bogus calorie number. That is why HRMs calorie readings for activities such as weight lifting and bikram yoga are useless--heart rate increases, but oxygen uptake does not. The HRM doesn 't know the difference.
Hopefully this helps--you can go to my profile and my blogs and find several articles that address these issues.
Adzak,
You seem to be really knowledgable on this issue. Its still hard me me to understand how more variables (heart rate, weight, height, gender-). Wouldn't be better than less..
Anyways,
How would you recommend more accurately measure calorie expenditure for a well conditioned female Athlete. Are there any better devices. For example- I do 2 rounds on the heavy bag- 2 minutes spinning for 30 minutes- and I am measuring using my Polar- (Clearly these are not machines that have calorie readings, anyways). Is there anything better than the Polar HRM?:0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
I don't understand...
Your calorie expenditure depends on how much oxygen your body uses. During aerobic activity, the need for oxygen increases, therefore the heart beats faster to deliver more blood to the working tissues so that oxygen can be extracted.
For simple aerobic movements, such as walking or running, there is a relatively fixed energy cost for any workout intensity. For example, walking at 3.0 mph on level ground requires about 10.5 ml of oxygen per kg of body wt per minute (ml/kg/min). Unless you are really short or really tall or really obese, that energy cost of 10.5 ml/kg/min is the same for everyone. For walking 4.0 mph, the cost is about 14 ml/kg/min, running 6.0 mph is about 35 ml/kg/min, and so on. We burn a fixed number of calories for every milliliter of O2 consumed, so knowing the energy cost makes it simple to estimate calorie burn with good accuracy.
You'll note that I haven't mentioned heart rate yet. That's because if we know the oxygen cost of the activity, then heart rate is irrelevant. Walking and running are simple activities--they have been well researched and the oxygen cost (and therefore the calories burn) of any combination and speed and elevation can be easily estimated using established equations. So, we don't need heart rate, or gender, or fitness level or anything else except weight (heavier bodies burn more calories than lighter ones).
Where heart rate becomes necessary is when we perform aerobic exercise movements that are not simple, not continuous, or do not have consistent established movements common to all individuals. For these activities, there are no established equations for estimating oxygen uptake.
However, during steady-state aerobic exercise, there is a consistent relationship between heart rate and oxygen uptake. Changes in oxygen uptake are accompanied by predictable changes in heart rate. For example we know that a heart rate of 70% of one's maximum heart rate corresponds to about 57% of maximal oxygen uptake (VO2max). If we know that a persons max heart rate is 180 beats/min and their VO2max is 40 ml/kg/min and they are working at a heart rate of 126 (70% of maximum), it means their oxygen uptake is about 23 ml/kg/min (57% of the VO2max of 40). From that 23 ml/kg/min, we can estimate calorie expenditure.
That, in essence, is how HRMs work. They develop algorithms based on the relationship of heart rate to oxygen uptake and then validate them by comparing the predicted calorie burn from the HRM to the actual measured calorie burn for the same activity. The nature of math is such (and I can't explain it any better because I am not a math expert) and including more variables--height, gender, age, along with weight--increases the accuracy of the HRM's algorithms, so that's why they include these extra variables.
Right away, you can see two things that will affect the accuracy of HRM calorie estimates: if you are estimating maximum heart rate and you are estimating maximum oxygen uptake, then overall accuracy of the HRM will be affected. Not everyone is able to get these numbers, which is why HRMs are probably only about 80% accurate under the best of conditions.
You can also see that if your VO2 max increases over time with training, but the HRM settings aren't updated, you will see a decrease in your calorie numbers. That's because your heart rate has decreased for the same workload--it has decreased because your maximum has INCREASED--now the work level (that 14 ml/kg/min example from before) represents a lower percentage of your maximum. The display suggests you are burning fewer calories, but in fact it's just your setup information that is outdated.
Lastly, HRM algorithms are only accurate when an increase in heart rate is accompanied by an increase in oxygen uptake--i.e. during steady-state cardio exercise.
Any condition or activity that causes heart rate to increase WITHOUT and increase in oxygen uptake will result in a bogus calorie number. That is why HRMs calorie readings for activities such as weight lifting and bikram yoga are useless--heart rate increases, but oxygen uptake does not. The HRM doesn 't know the difference.
Hopefully this helps--you can go to my profile and my blogs and find several articles that address these issues.
Adzak,
You seem to be really knowledgable on this issue. Its still hard me me to understand how more variables (heart rate, weight, height, gender-). Wouldn't be better than less..
Anyways,
How would you recommend more accurately measure calorie expenditure for a well conditioned female Athlete. Are there any better devices. For example- I do 2 rounds on the heavy bag- 2 minutes spinning for 30 minutes- and I am measuring using my Polar- (Clearly these are not machines that have calorie readings, anyways). Is there anything better than the Polar HRM?:
In your case, probably not. I don't mean to be too negative about Polars (I've used their products myself for 20 years). They are the best at this--the limitations are because of our physiology.
The only caveat about using HRMs for the activities you describe is that when you are doing exercise that works primarily upper body, the HRMs will tend to overestimate calories somewhat. That's because upper body work results in a higher heart rate for comparable levels of oxygen uptake than leg work. For example, if you were doing a 50 watt workload using an arm ergometer, your heart rate would be higher than doing the same 50 watt workload with your legs on a bike. Yet both would burn the same calories (since workload was the same). The HRM doesn't know the difference, so it will give you a higher reading for the arm work.
So the a Polar or Suunto HRM is still probably going to be the best bet, despite their limitations. You need to make sure they are set up properly (get as close as you can with your true maximum heart rate and VO2 max), updated when weight or fitness level changes, and then you just have to be aware that they are not precise instruments, so there will still be some trial and error involved.
The really huge discrepancies occur in the following situations: doing exercises that can result in high heart rates but little or no increase in oxygen uptake (e.g. lifting weights), or doing exercises under conditions of thermal stress (e.g. bikram yoga)--once again, heart rate increases, but oxygen uptake and calorie burn do not, or when people have naturally high heart rates, where their true max heart rate is 20+ beats above the age-predicted number and they don't change the setup.
Otherwise, HRMs will be about 80% accurate (at best) in my experience. And that's OK --I don't think it really needs to be closer than that.0 -
No, they typically majorly overestimate calories burned. I would highly recommend investing in a heart rate monitor (polar ft4) which is constantly gauging your heartrate and giving you a much, much more accurate calorie expenditure.
--
edit-- even when you enter in your weight.. heart rate is a crucial determinant.
Actually, for walking and running, the energy cost of the activity (e.g. speed and incline) is well-established and relatively easy to calculate. All you need is body weight. Heart rate is irrelevant in this case.
I don't understand...
Your calorie expenditure depends on how much oxygen your body uses. During aerobic activity, the need for oxygen increases, therefore the heart beats faster to deliver more blood to the working tissues so that oxygen can be extracted.
For simple aerobic movements, such as walking or running, there is a relatively fixed energy cost for any workout intensity. For example, walking at 3.0 mph on level ground requires about 10.5 ml of oxygen per kg of body wt per minute (ml/kg/min). Unless you are really short or really tall or really obese, that energy cost of 10.5 ml/kg/min is the same for everyone. For walking 4.0 mph, the cost is about 14 ml/kg/min, running 6.0 mph is about 35 ml/kg/min, and so on. We burn a fixed number of calories for every milliliter of O2 consumed, so knowing the energy cost makes it simple to estimate calorie burn with good accuracy.
You'll note that I haven't mentioned heart rate yet. That's because if we know the oxygen cost of the activity, then heart rate is irrelevant. Walking and running are simple activities--they have been well researched and the oxygen cost (and therefore the calories burn) of any combination and speed and elevation can be easily estimated using established equations. So, we don't need heart rate, or gender, or fitness level or anything else except weight (heavier bodies burn more calories than lighter ones).
Where heart rate becomes necessary is when we perform aerobic exercise movements that are not simple, not continuous, or do not have consistent established movements common to all individuals. For these activities, there are no established equations for estimating oxygen uptake.
However, during steady-state aerobic exercise, there is a consistent relationship between heart rate and oxygen uptake. Changes in oxygen uptake are accompanied by predictable changes in heart rate. For example we know that a heart rate of 70% of one's maximum heart rate corresponds to about 57% of maximal oxygen uptake (VO2max). If we know that a persons max heart rate is 180 beats/min and their VO2max is 40 ml/kg/min and they are working at a heart rate of 126 (70% of maximum), it means their oxygen uptake is about 23 ml/kg/min (57% of the VO2max of 40). From that 23 ml/kg/min, we can estimate calorie expenditure.
That, in essence, is how HRMs work. They develop algorithms based on the relationship of heart rate to oxygen uptake and then validate them by comparing the predicted calorie burn from the HRM to the actual measured calorie burn for the same activity. The nature of math is such (and I can't explain it any better because I am not a math expert) and including more variables--height, gender, age, along with weight--increases the accuracy of the HRM's algorithms, so that's why they include these extra variables.
Right away, you can see two things that will affect the accuracy of HRM calorie estimates: if you are estimating maximum heart rate and you are estimating maximum oxygen uptake, then overall accuracy of the HRM will be affected. Not everyone is able to get these numbers, which is why HRMs are probably only about 80% accurate under the best of conditions.
You can also see that if your VO2 max increases over time with training, but the HRM settings aren't updated, you will see a decrease in your calorie numbers. That's because your heart rate has decreased for the same workload--it has decreased because your maximum has INCREASED--now the work level (that 14 ml/kg/min example from before) represents a lower percentage of your maximum. The display suggests you are burning fewer calories, but in fact it's just your setup information that is outdated.
Lastly, HRM algorithms are only accurate when an increase in heart rate is accompanied by an increase in oxygen uptake--i.e. during steady-state cardio exercise.
Any condition or activity that causes heart rate to increase WITHOUT and increase in oxygen uptake will result in a bogus calorie number. That is why HRMs calorie readings for activities such as weight lifting and bikram yoga are useless--heart rate increases, but oxygen uptake does not. The HRM doesn 't know the difference.
Hopefully this helps--you can go to my profile and my blogs and find several articles that address these issues.
Adzak,
You seem to be really knowledgable on this issue. Its still hard me me to understand how more variables (heart rate, weight, height, gender-). Wouldn't be better than less..
Anyways,
How would you recommend more accurately measure calorie expenditure for a well conditioned female Athlete. Are there any better devices. For example- I do 2 rounds on the heavy bag- 2 minutes spinning for 30 minutes- and I am measuring using my Polar- (Clearly these are not machines that have calorie readings, anyways). Is there anything better than the Polar HRM?:
In your case, probably not. I don't mean to be too negative about Polars (I've used their products myself for 20 years). They are the best at this--the limitations are because of our physiology.
The only caveat about using HRMs for the activities you describe is that when you are doing exercise that works primarily upper body, the HRMs will tend to overestimate calories somewhat. That's because upper body work results in a higher heart rate for comparable levels of oxygen uptake than leg work. For example, if you were doing a 50 watt workload using an arm ergometer, your heart rate would be higher than doing the same 50 watt workload with your legs on a bike. Yet both would burn the same calories (since workload was the same). The HRM doesn't know the difference, so it will give you a higher reading for the arm work.
So the a Polar or Suunto HRM is still probably going to be the best bet, despite their limitations. You need to make sure they are set up properly (get as close as you can with your true maximum heart rate and VO2 max), updated when weight or fitness level changes, and then you just have to be aware that they are not precise instruments, so there will still be some trial and error involved.
The really huge discrepancies occur in the following situations: doing exercises that can result in high heart rates but little or no increase in oxygen uptake (e.g. lifting weights), or doing exercises under conditions of thermal stress (e.g. bikram yoga)--once again, heart rate increases, but oxygen uptake and calorie burn do not, or when people have naturally high heart rates, where their true max heart rate is 20+ beats above the age-predicted number and they don't change the setup.
Otherwise, HRMs will be about 80% accurate (at best) in my experience. And that's OK --I don't think it really needs to be closer than that.
That works- typically I cut 100 or 200 calories off what it tells me anyways- for good measure. Thanks!0
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