Validity of Machines

saschakhan
saschakhan Posts: 4 Member
edited November 23 in Health and Weight Loss
Hi, my name is Sascha. I'm new to this site. So I I've been a runner for several years now. I've run many half and full marathons. However, after my last marathon in October, I had incredible pain in my left foot every time I ran, so I haven't been running as much. Also, I have completely gotten out of shape over the last year and a half. I'd say I've probably gained about 20-25 pounds. I seriously cannot stand being overweight (I currently weigh 188 and am 5' 11''), so I've gone back to the elliptical to try and lose weight. I've been doing elliptical for several weeks now. I use the manual option and put in my weight and age, but I'm still not sure how much I can trust the machine when it comes to calories. Every time I use the elliptical, I set it to 5 incline and 20 resistance (max for this elliptical). I usually do an hour and five minutes, in which I average 10 miles and 1400 calories, at least according to the machine. I was always of the mindset that the reason elliptical burns so many calories is because of the foot and arm motion, so I almost never take my hands off the handles except to check heart rate maybe once or twice in the 95 minute workout. I'm just wondering if anyone else has any thoughts in regards to the validity of the elliptical when it comes to calorie count. By the way, the elliptical I use is a PRECOR AMT.

Replies

  • Muscleflex79
    Muscleflex79 Posts: 1,917 Member
    I don't think 1400 calories is accurate. Especially not for an hour workout.

    this! very, very unlikely you are burning 1400 calories per hour on an elliptical!
  • mitch16
    mitch16 Posts: 2,113 Member
    I would probably halve that, if you're eating back exercise calories. Do you have a heart rate monitor? That would probably give a slightly better estimate.
  • Azdak
    Azdak Posts: 8,281 Member
    edited November 2017
    Ellipticals are notorious for inflated calorie readings. It’s because the motion is unique to each machine and companies are unwilling to do the research needed to develop reliable, machine-specific algorithms. The varied nature of the AMT, makes this problem even worse. Based on your weight and the avg person’s fitness level, your calorie burn is more likely in the 700-750 per hour range.

    PS: Using arms will not by itself increase the calorie burn—only if adding arms allows you to maintain a higher workload. The AMT works best as an arm/leg movement, so you are doing the right thing—just not for the reasons you think.
  • robertw486
    robertw486 Posts: 2,399 Member
    saschakhan wrote: »
    Hi, my name is Sascha. I'm new to this site. So I I've been a runner for several years now. I've run many half and full marathons. However, after my last marathon in October, I had incredible pain in my left foot every time I ran, so I haven't been running as much. Also, I have completely gotten out of shape over the last year and a half. I'd say I've probably gained about 20-25 pounds. I seriously cannot stand being overweight (I currently weigh 188 and am 5' 11''), so I've gone back to the elliptical to try and lose weight. I've been doing elliptical for several weeks now. I use the manual option and put in my weight and age, but I'm still not sure how much I can trust the machine when it comes to calories. Every time I use the elliptical, I set it to 5 incline and 20 resistance (max for this elliptical). I usually do an hour and five minutes, in which I average 10 miles and 1400 calories, at least according to the machine. I was always of the mindset that the reason elliptical burns so many calories is because of the foot and arm motion, so I almost never take my hands off the handles except to check heart rate maybe once or twice in the 95 minute workout. I'm just wondering if anyone else has any thoughts in regards to the validity of the elliptical when it comes to calorie count. By the way, the elliptical I use is a PRECOR AMT.

    More than anything, it depends on your fitness level as to whether the machine is close or not on the calorie burn estimation. Being you are obviously a trained runner quite possible that it's close.

    Most Precor machines do not measure true miles, but a "mile equivalent" based on stride length and resistance. With the AMT, it would also have to factor the vertical axis so possibly a more complicated system. But at any rate, they measure approximate energy required to run a mile on flat ground and call it a mile for distance. But they use a system that can be very accurate.

    If in fact you are that fast of a runner that you can run 10 mph for an hour, the calorie estimate of the machine is close to accepted formulas for your weight and speed. (Side note: If you are that quick, GO YOU!) I've never hit that number on the elliptical, but I've never been a really fast runner either.


    I have a few studies done for the Navy that test elliptical machines for possible use in physical testing, and I think at least one of them includes one or more of the AMT machines. I can't remember which one, but one test actually included testing machine calories vs a metabolic cart. Despite frequent claims that machines usually over estimate, I think more of the machines actually under estimated calorie expenditure. When I get a chance I'll find the links, but first I have to find the PDF so I can search for a link. :)
  • jesspen91
    jesspen91 Posts: 1,383 Member
    Also make sure that you enter your age and weight into the machine as this will affect your calorie burn.
  • fuzzylop72
    fuzzylop72 Posts: 651 Member
    edited November 2017
    I think 0.072 * bodyweight (in lbs) is the calories per minute rate (2.16 per 30m) per the harvard estimates is reasonable to start off with (although, perhaps that's inflated too).
  • DX2JX2
    DX2JX2 Posts: 1,921 Member
    1400 per hour is a bit generous. Even running 10 miles would only net you something on order of 1100 or so at your weight.

    I'm similar to your weight and my burn for an hour on the elliptical is a little north of 500. With your added resistance and speed, I'd wager that something closer to 600-700 is more in the ballpark for your workout.
  • andrea4736
    andrea4736 Posts: 211 Member
    It's funny because I hear of so many machines being way off. It definitely depends on the machine. While I was just on vacation, I used the elliptical at the hotel. I wore my regular HRM but inputted my info into the machine. They were only like 10 cals different.
  • saschakhan
    saschakhan Posts: 4 Member
    DX2JX2 wrote: »
    1400 per hour is a bit generous. Even running 10 miles would only net you something on order of 1100 or so at your weight.

    I'm similar to your weight and my burn for an hour on the elliptical is a little north of 500. With your added resistance and speed, I'd wager that something closer to 600-700 is more in the ballpark for your workout.

    To your point about running, that's what I was talking about in regards to elliptical. I would think that because of the constant arm motion on the elliptical, that the elliptical should burn more than just running. So does your elliptical actually say 500 or are you measuring this in some other way?
  • saschakhan
    saschakhan Posts: 4 Member
    jesspen91 wrote: »
    Also make sure that you enter your age and weight into the machine as this will affect your calorie burn.

    I do put in my age and weight into the machine. I asked the fitness instructor at the YMCA that I go to, and she said this should give me a more accurate assessment. After putting in my info., it's reading about an extra 100 calories burned per hour. From around 1300 to 1400+.
  • saschakhan
    saschakhan Posts: 4 Member
    Azdak wrote: »
    Ellipticals are notorious for inflated calorie readings. It’s because the motion is unique to each machine and companies are unwilling to do the research needed to develop reliable, machine-specific algorithms. The varied nature of the AMT, makes this problem even worse. Based on your weight and the avg person’s fitness level, your calorie burn is more likely in the 700-750 per hour range.

    PS: Using arms will not by itself increase the calorie burn—only if adding arms allows you to maintain a higher workload. The AMT works best as an arm/leg movement, so you are doing the right thing—just not for the reasons you think.

    I have read the same thing on the internet about ellipticals. That's a main reason I am concerned. However, it's hard for me to fathom that I'm only burning half of what the machine is tracking, even after putting in my weight and age. One reason I might have to think that the machine is somewhat accurate is because I've noticed I burn significantly more calories than other individuals who do the elliptical on less incline and resistance. But again, 1400 is a huge number. Also, I guess I'm not really understanding your point about arms. So are you saying that it is likely that I will burn the same calories even if I keep my hands on the handles that are stuck in position?
  • Azdak
    Azdak Posts: 8,281 Member
    saschakhan wrote: »
    Azdak wrote: »
    Ellipticals are notorious for inflated calorie readings. It’s because the motion is unique to each machine and companies are unwilling to do the research needed to develop reliable, machine-specific algorithms. The varied nature of the AMT, makes this problem even worse. Based on your weight and the avg person’s fitness level, your calorie burn is more likely in the 700-750 per hour range.

    PS: Using arms will not by itself increase the calorie burn—only if adding arms allows you to maintain a higher workload. The AMT works best as an arm/leg movement, so you are doing the right thing—just not for the reasons you think.

    I have read the same thing on the internet about ellipticals. That's a main reason I am concerned. However, it's hard for me to fathom that I'm only burning half of what the machine is tracking, even after putting in my weight and age. One reason I might have to think that the machine is somewhat accurate is because I've noticed I burn significantly more calories than other individuals who do the elliptical on less incline and resistance. But again, 1400 is a huge number. Also, I guess I'm not really understanding your point about arms. So are you saying that it is likely that I will burn the same calories even if I keep my hands on the handles that are stuck in position?

    Calories burned during exercise is based on: body weight and the workload being performed.

    Let’s say you work on the AMT legs only and we measured your power output at 200 watts.
    If you then did the AMT with arms and legs, but did the same power of 200 watts, your calorie burn would be the same as doing 200 watts with legs only.

    It’s the 200 watts that determines calorie burn, not whether the effort was expended using arms only or arms and legs.

    Now it might *feel* different. Trying to do 200 watts with legs only might feel harder because the work is being done by a smaller amount of muscle, but it wouldn’t change the calories.

    If adding arms and legs allowed you to push harder and do 250 watts, then you would burn more calories. Again, not because you added arms, but because you did a higher workload (more watts).

    To your other point: you could very well be working harder than the others—that means you are burning more calories than they are, but it doesn’t validate the accuracy of the machine count—their readings will be as inaccurate as yours.

    The main reason I say your calorie burn is grossly overestimated is that, at your weight, you would have to run a sustained speed of at least 9 mph (6:40 mile) to burn 1400 calories in an hour. Not many average exercisers can do that, and even fewer can do that on an AMT. I would wager that, given the random movement of the AMT, it is almost unthinkable that anyone could sustain that level of effort (unless it was a very fit 300 pounder).
  • yirara
    yirara Posts: 9,944 Member
    fuzzylop72 wrote: »
    I think 0.072 * bodyweight (in lbs) is the calories per minute rate (2.16 per 30m) per the harvard estimates is reasonable to start off with (although, perhaps that's inflated too).

    For running, the generally accepted amount is 0.63*weight in lbs * distance in miles. An eliptical burns less as one does not jump against gravity. The feet stay on the ground the whole time. However, it's the question how you calculate distance anyway on such a thing. I would probably use the running equation and use a fraction of it.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    yirara wrote: »
    fuzzylop72 wrote: »
    I think 0.072 * bodyweight (in lbs) is the calories per minute rate (2.16 per 30m) per the harvard estimates is reasonable to start off with (although, perhaps that's inflated too).

    For running, the generally accepted amount is 0.63*weight in lbs * distance in miles. An eliptical burns less as one does not jump against gravity. The feet stay on the ground the whole time. However, it's the question how you calculate distance anyway on such a thing. I would probably use the running equation and use a fraction of it.

    Generally, the elliptical burns less, but It certainly can burn more if you up the intensity and speed.
  • yirara
    yirara Posts: 9,944 Member
    yirara wrote: »
    fuzzylop72 wrote: »
    I think 0.072 * bodyweight (in lbs) is the calories per minute rate (2.16 per 30m) per the harvard estimates is reasonable to start off with (although, perhaps that's inflated too).

    For running, the generally accepted amount is 0.63*weight in lbs * distance in miles. An eliptical burns less as one does not jump against gravity. The feet stay on the ground the whole time. However, it's the question how you calculate distance anyway on such a thing. I would probably use the running equation and use a fraction of it.

    Generally, the elliptical burns less, but It certainly can burn more if you up the intensity and speed.

    True, but it's difficult to quantify as they generally don't provide data in wats.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    yirara wrote: »
    yirara wrote: »
    fuzzylop72 wrote: »
    I think 0.072 * bodyweight (in lbs) is the calories per minute rate (2.16 per 30m) per the harvard estimates is reasonable to start off with (although, perhaps that's inflated too).

    For running, the generally accepted amount is 0.63*weight in lbs * distance in miles. An eliptical burns less as one does not jump against gravity. The feet stay on the ground the whole time. However, it's the question how you calculate distance anyway on such a thing. I would probably use the running equation and use a fraction of it.

    Generally, the elliptical burns less, but It certainly can burn more if you up the intensity and speed.

    True, but it's difficult to quantify as they generally don't provide data in wats.

    Indeed. And Most people aren't putting in the effort to get the running through knee deep water sensation.
  • robertw486
    robertw486 Posts: 2,399 Member
    edited November 2017
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

  • PAV8888
    PAV8888 Posts: 14,254 Member
    dns error :disappointed:
  • Azdak
    Azdak Posts: 8,281 Member
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.
  • robertw486
    robertw486 Posts: 2,399 Member
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.
  • Azdak
    Azdak Posts: 8,281 Member
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.

    I am just reading the graph which shows that, when the machine indicated approx 157 calories burned, the measured burn was less than 100. Unless I am completely misreading it.

    FWIW, my interpretation is a much better “fit” to the OPs reported numbers. I can say with a 95% “confidence interval” that a 180 pound man did not burn 1400 calories in a little over 60 min.
  • davidylin
    davidylin Posts: 228 Member
    The other thing to note is that most of the calorie estimates are based on data from athletes giving consistent and constant effort, something non-athletes tend not to do.

    Notably, military personnel tend to be pretty fit and so their data is probably a poor estimate for us normal folks too. I take the calories reported by machines to be advisories on my relative level of effort.
  • robertw486
    robertw486 Posts: 2,399 Member
    edited November 2017
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.

    I am just reading the graph which shows that, when the machine indicated approx 157 calories burned, the measured burn was less than 100. Unless I am completely misreading it.

    FWIW, my interpretation is a much better “fit” to the OPs reported numbers. I can say with a 95% “confidence interval” that a 180 pound man did not burn 1400 calories in a little over 60 min.

    I think you're making the same error as I did at first. The line you are looking at is the Star Trac TBT machine. The line for the AMT is the shorter one that intersects the red line at the high end of the calorie burn. The length of the line indicates the data spread, so the two Precor machines noted in the text are the ones closer to the line of identity. The AMT machine under estimated the calorie burn.

    As for the comment on the OP's calorie burn, I can't guess with any confidence interval to know how hard they are working. In my original comment I stated a 10 MPH hour, being less generous than your statement of at least 9 MPH. Being that gross calorie burn is being used, it would no doubt be a quick distance runner. But when someone states multiple long distance runs I would be more inclined to think that they may be fairly quick as well.

    davidylin wrote: »
    The other thing to note is that most of the calorie estimates are based on data from athletes giving consistent and constant effort, something non-athletes tend not to do.

    Notably, military personnel tend to be pretty fit and so their data is probably a poor estimate for us normal folks too. I take the calories reported by machines to be advisories on my relative level of effort.

    I'm not sure about other machines, but our Precor slows quickly at anything other than very light resistance. The data screens show any pace changes very quickly, so even attempting a constant pace shows power changes.

    As for the calorie reports, I take them with a grain of salt in most cases. But when quite a few brands have testing such as the above, I note the error rates and factor that in as well. I still personally think one of the bigger problems probably lies in the fact that they estimate gross calories, rather than just report net energy use.
  • Azdak
    Azdak Posts: 8,281 Member
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.

    I am just reading the graph which shows that, when the machine indicated approx 157 calories burned, the measured burn was less than 100. Unless I am completely misreading it.

    FWIW, my interpretation is a much better “fit” to the OPs reported numbers. I can say with a 95% “confidence interval” that a 180 pound man did not burn 1400 calories in a little over 60 min.

    I think you're making the same error as I did at first. The line you are looking at is the Star Trac TBT machine. The line for the AMT is the shorter one that intersects the red line at the high end of the calorie burn. The length of the line indicates the data spread, so the two Precor machines noted in the text are the ones closer to the line of identity. The AMT machine under estimated the calorie burn.

    As for the comment on the OP's calorie burn, I can't guess with any confidence interval to know how hard they are working. In my original comment I stated a 10 MPH hour, being less generous than your statement of at least 9 MPH. Being that gross calorie burn is being used, it would no doubt be a quick distance runner. But when someone states multiple long distance runs I would be more inclined to think that they may be fairly quick as well.

    davidylin wrote: »
    The other thing to note is that most of the calorie estimates are based on data from athletes giving consistent and constant effort, something non-athletes tend not to do.

    Notably, military personnel tend to be pretty fit and so their data is probably a poor estimate for us normal folks too. I take the calories reported by machines to be advisories on my relative level of effort.

    I'm not sure about other machines, but our Precor slows quickly at anything other than very light resistance. The data screens show any pace changes very quickly, so even attempting a constant pace shows power changes.

    As for the calorie reports, I take them with a grain of salt in most cases. But when quite a few brands have testing such as the above, I note the error rates and factor that in as well. I still personally think one of the bigger problems probably lies in the fact that they estimate gross calories, rather than just report net energy use.

    OK, I see the mistake. Thanks for pointing that out. I'm still not buying the OPs numbers, but that's just one data point. I may have to ask some other people to give me their calorie numbers. We have one AMT and very few people use it, so I don't have a lot of local, anecdotal data to consider, but now I am curious.
  • robertw486
    robertw486 Posts: 2,399 Member
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.

    I am just reading the graph which shows that, when the machine indicated approx 157 calories burned, the measured burn was less than 100. Unless I am completely misreading it.

    FWIW, my interpretation is a much better “fit” to the OPs reported numbers. I can say with a 95% “confidence interval” that a 180 pound man did not burn 1400 calories in a little over 60 min.

    I think you're making the same error as I did at first. The line you are looking at is the Star Trac TBT machine. The line for the AMT is the shorter one that intersects the red line at the high end of the calorie burn. The length of the line indicates the data spread, so the two Precor machines noted in the text are the ones closer to the line of identity. The AMT machine under estimated the calorie burn.

    As for the comment on the OP's calorie burn, I can't guess with any confidence interval to know how hard they are working. In my original comment I stated a 10 MPH hour, being less generous than your statement of at least 9 MPH. Being that gross calorie burn is being used, it would no doubt be a quick distance runner. But when someone states multiple long distance runs I would be more inclined to think that they may be fairly quick as well.

    davidylin wrote: »
    The other thing to note is that most of the calorie estimates are based on data from athletes giving consistent and constant effort, something non-athletes tend not to do.

    Notably, military personnel tend to be pretty fit and so their data is probably a poor estimate for us normal folks too. I take the calories reported by machines to be advisories on my relative level of effort.

    I'm not sure about other machines, but our Precor slows quickly at anything other than very light resistance. The data screens show any pace changes very quickly, so even attempting a constant pace shows power changes.

    As for the calorie reports, I take them with a grain of salt in most cases. But when quite a few brands have testing such as the above, I note the error rates and factor that in as well. I still personally think one of the bigger problems probably lies in the fact that they estimate gross calories, rather than just report net energy use.

    OK, I see the mistake. Thanks for pointing that out. I'm still not buying the OPs numbers, but that's just one data point. I may have to ask some other people to give me their calorie numbers. We have one AMT and very few people use it, so I don't have a lot of local, anecdotal data to consider, but now I am curious.

    Like I said, I couldn't tell which machine was which until I read the explanation of the line lengths and relationship to data spread. But I'd be interested to see what kinds of numbers the more fit people using the AMT at your place of work can output. Being the AMT has a unique motion, I'd think it might be more forgiving of different muscle use than many "normal" elliptical machines. And though I've never used any cardio devices with upper body input long term, I would think most people could up output at least some.

    I've both talked to people personally and seen posts online indicating that many people manage a higher calorie burn on the AMT machines vs the elliptical. Since the stride length and height is instantly variable, to me this makes sense. But more than user input, the testing shows it measures power fairly accurately. I know some of the equipment manufacturers put more effort into testing and validation, and Precor has stated sources of this as far back as they sold elliptical machines. But they still openly state that calorie burns are estimates and not 100% accurate. But we know that nothing is 100%, and probably few devices short of a metabolic cart are even within 5% most of the time. I'd be happy with 10% myself.

    Testing of fitness power meters shows a spread about as wide, which is no real surprise. Any decent elliptical will only measure as accurately as the power meter accuracy AND the inputs they use in their algorithms for BMR/age/sex equations. I really think they might be better off just showing net output, but the average user probably likes seeing gross, mile equivalents, etc.


    saschakhan wrote: »
    Hi, my name is Sascha. I'm new to this site. So I I've been a runner for several years now. I've run many half and full marathons. However, after my last marathon in October, I had incredible pain in my left foot every time I ran, so I haven't been running as much. Also, I have completely gotten out of shape over the last year and a half. I'd say I've probably gained about 20-25 pounds. I seriously cannot stand being overweight (I currently weigh 188 and am 5' 11''), so I've gone back to the elliptical to try and lose weight. I've been doing elliptical for several weeks now. I use the manual option and put in my weight and age, but I'm still not sure how much I can trust the machine when it comes to calories. Every time I use the elliptical, I set it to 5 incline and 20 resistance (max for this elliptical). I usually do an hour and five minutes, in which I average 10 miles and 1400 calories, at least according to the machine. I was always of the mindset that the reason elliptical burns so many calories is because of the foot and arm motion, so I almost never take my hands off the handles except to check heart rate maybe once or twice in the 95 minute workout. I'm just wondering if anyone else has any thoughts in regards to the validity of the elliptical when it comes to calorie count. By the way, the elliptical I use is a PRECOR AMT.

    I noticed the bolded after my initial posts. This could easily bring the calorie burn into the realm of the more average user.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.

    I am just reading the graph which shows that, when the machine indicated approx 157 calories burned, the measured burn was less than 100. Unless I am completely misreading it.

    FWIW, my interpretation is a much better “fit” to the OPs reported numbers. I can say with a 95% “confidence interval” that a 180 pound man did not burn 1400 calories in a little over 60 min.

    I think you're making the same error as I did at first. The line you are looking at is the Star Trac TBT machine. The line for the AMT is the shorter one that intersects the red line at the high end of the calorie burn. The length of the line indicates the data spread, so the two Precor machines noted in the text are the ones closer to the line of identity. The AMT machine under estimated the calorie burn.

    As for the comment on the OP's calorie burn, I can't guess with any confidence interval to know how hard they are working. In my original comment I stated a 10 MPH hour, being less generous than your statement of at least 9 MPH. Being that gross calorie burn is being used, it would no doubt be a quick distance runner. But when someone states multiple long distance runs I would be more inclined to think that they may be fairly quick as well.

    davidylin wrote: »
    The other thing to note is that most of the calorie estimates are based on data from athletes giving consistent and constant effort, something non-athletes tend not to do.

    Notably, military personnel tend to be pretty fit and so their data is probably a poor estimate for us normal folks too. I take the calories reported by machines to be advisories on my relative level of effort.

    I'm not sure about other machines, but our Precor slows quickly at anything other than very light resistance. The data screens show any pace changes very quickly, so even attempting a constant pace shows power changes.

    As for the calorie reports, I take them with a grain of salt in most cases. But when quite a few brands have testing such as the above, I note the error rates and factor that in as well. I still personally think one of the bigger problems probably lies in the fact that they estimate gross calories, rather than just report net energy use.

    OK, I see the mistake. Thanks for pointing that out. I'm still not buying the OPs numbers, but that's just one data point. I may have to ask some other people to give me their calorie numbers. We have one AMT and very few people use it, so I don't have a lot of local, anecdotal data to consider, but now I am curious.

    Like I said, I couldn't tell which machine was which until I read the explanation of the line lengths and relationship to data spread. But I'd be interested to see what kinds of numbers the more fit people using the AMT at your place of work can output. Being the AMT has a unique motion, I'd think it might be more forgiving of different muscle use than many "normal" elliptical machines. And though I've never used any cardio devices with upper body input long term, I would think most people could up output at least some.

    I've both talked to people personally and seen posts online indicating that many people manage a higher calorie burn on the AMT machines vs the elliptical. Since the stride length and height is instantly variable, to me this makes sense. But more than user input, the testing shows it measures power fairly accurately. I know some of the equipment manufacturers put more effort into testing and validation, and Precor has stated sources of this as far back as they sold elliptical machines. But they still openly state that calorie burns are estimates and not 100% accurate. But we know that nothing is 100%, and probably few devices short of a metabolic cart are even within 5% most of the time. I'd be happy with 10% myself.

    Testing of fitness power meters shows a spread about as wide, which is no real surprise. Any decent elliptical will only measure as accurately as the power meter accuracy AND the inputs they use in their algorithms for BMR/age/sex equations. I really think they might be better off just showing net output, but the average user probably likes seeing gross, mile equivalents, etc.


    saschakhan wrote: »
    Hi, my name is Sascha. I'm new to this site. So I I've been a runner for several years now. I've run many half and full marathons. However, after my last marathon in October, I had incredible pain in my left foot every time I ran, so I haven't been running as much. Also, I have completely gotten out of shape over the last year and a half. I'd say I've probably gained about 20-25 pounds. I seriously cannot stand being overweight (I currently weigh 188 and am 5' 11''), so I've gone back to the elliptical to try and lose weight. I've been doing elliptical for several weeks now. I use the manual option and put in my weight and age, but I'm still not sure how much I can trust the machine when it comes to calories. Every time I use the elliptical, I set it to 5 incline and 20 resistance (max for this elliptical). I usually do an hour and five minutes, in which I average 10 miles and 1400 calories, at least according to the machine. I was always of the mindset that the reason elliptical burns so many calories is because of the foot and arm motion, so I almost never take my hands off the handles except to check heart rate maybe once or twice in the 95 minute workout. I'm just wondering if anyone else has any thoughts in regards to the validity of the elliptical when it comes to calorie count. By the way, the elliptical I use is a PRECOR AMT.

    I noticed the bolded after my initial posts. This could easily bring the calorie burn into the realm of the more average user.

    10 miles at max resistance is a big deal. 900-1000 is probably more likely, and yes. 65 vs 95 minutes certainly matters
  • robertw486
    robertw486 Posts: 2,399 Member
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Azdak wrote: »
    robertw486 wrote: »
    Here is a chart from actual comparison of a few machines vs a metabolic cart. One of the Precor AMT machines is used, and is noted in the full text as a having the lowest data spread.

    roen9uci2zm0.jpg

    The full text of the study that is the source of the above is at....

    dtic.mil/get-tr-doc/pdf?AD=ADA590107


    Without data, taking a guess at what any given machine is doing is just that... a guess. Being that we can't possibly know how hard any given user is working, figuring out the accuracy if the calorie burns reported is still just a guess. Thankfully there are studies for some machines that help narrow things down.

    Thanks for the posting. From what I read (just skimming), the study was looking at consistency as much as absolute accuracy. In other words, even if the machine was inaccurate, it was consistent, so that you could add a correction factor to the machine display.

    If I am reading it correctly, the graph also suggests that, at higher intensities, the AMT overestimated calorie burn by over 60%, which is consisted with my estimates.

    Consistency was the primary concern, so they could simply employ an offset to the machines. There are actually several other studies as they worked on implementing this project for testing purposes.

    I'm not seeing the large error rate, as the AMT machine had a very low data spread and actually under reported calorie burn as the test progressed. I'm not quite sure how they are getting the lower end error in many machines, since they will always start at the zero count. I'm wondering if they somehow were moving the machines as they set the user weights and such.

    I am just reading the graph which shows that, when the machine indicated approx 157 calories burned, the measured burn was less than 100. Unless I am completely misreading it.

    FWIW, my interpretation is a much better “fit” to the OPs reported numbers. I can say with a 95% “confidence interval” that a 180 pound man did not burn 1400 calories in a little over 60 min.

    I think you're making the same error as I did at first. The line you are looking at is the Star Trac TBT machine. The line for the AMT is the shorter one that intersects the red line at the high end of the calorie burn. The length of the line indicates the data spread, so the two Precor machines noted in the text are the ones closer to the line of identity. The AMT machine under estimated the calorie burn.

    As for the comment on the OP's calorie burn, I can't guess with any confidence interval to know how hard they are working. In my original comment I stated a 10 MPH hour, being less generous than your statement of at least 9 MPH. Being that gross calorie burn is being used, it would no doubt be a quick distance runner. But when someone states multiple long distance runs I would be more inclined to think that they may be fairly quick as well.

    davidylin wrote: »
    The other thing to note is that most of the calorie estimates are based on data from athletes giving consistent and constant effort, something non-athletes tend not to do.

    Notably, military personnel tend to be pretty fit and so their data is probably a poor estimate for us normal folks too. I take the calories reported by machines to be advisories on my relative level of effort.

    I'm not sure about other machines, but our Precor slows quickly at anything other than very light resistance. The data screens show any pace changes very quickly, so even attempting a constant pace shows power changes.

    As for the calorie reports, I take them with a grain of salt in most cases. But when quite a few brands have testing such as the above, I note the error rates and factor that in as well. I still personally think one of the bigger problems probably lies in the fact that they estimate gross calories, rather than just report net energy use.

    OK, I see the mistake. Thanks for pointing that out. I'm still not buying the OPs numbers, but that's just one data point. I may have to ask some other people to give me their calorie numbers. We have one AMT and very few people use it, so I don't have a lot of local, anecdotal data to consider, but now I am curious.

    Like I said, I couldn't tell which machine was which until I read the explanation of the line lengths and relationship to data spread. But I'd be interested to see what kinds of numbers the more fit people using the AMT at your place of work can output. Being the AMT has a unique motion, I'd think it might be more forgiving of different muscle use than many "normal" elliptical machines. And though I've never used any cardio devices with upper body input long term, I would think most people could up output at least some.

    I've both talked to people personally and seen posts online indicating that many people manage a higher calorie burn on the AMT machines vs the elliptical. Since the stride length and height is instantly variable, to me this makes sense. But more than user input, the testing shows it measures power fairly accurately. I know some of the equipment manufacturers put more effort into testing and validation, and Precor has stated sources of this as far back as they sold elliptical machines. But they still openly state that calorie burns are estimates and not 100% accurate. But we know that nothing is 100%, and probably few devices short of a metabolic cart are even within 5% most of the time. I'd be happy with 10% myself.

    Testing of fitness power meters shows a spread about as wide, which is no real surprise. Any decent elliptical will only measure as accurately as the power meter accuracy AND the inputs they use in their algorithms for BMR/age/sex equations. I really think they might be better off just showing net output, but the average user probably likes seeing gross, mile equivalents, etc.


    saschakhan wrote: »
    Hi, my name is Sascha. I'm new to this site. So I I've been a runner for several years now. I've run many half and full marathons. However, after my last marathon in October, I had incredible pain in my left foot every time I ran, so I haven't been running as much. Also, I have completely gotten out of shape over the last year and a half. I'd say I've probably gained about 20-25 pounds. I seriously cannot stand being overweight (I currently weigh 188 and am 5' 11''), so I've gone back to the elliptical to try and lose weight. I've been doing elliptical for several weeks now. I use the manual option and put in my weight and age, but I'm still not sure how much I can trust the machine when it comes to calories. Every time I use the elliptical, I set it to 5 incline and 20 resistance (max for this elliptical). I usually do an hour and five minutes, in which I average 10 miles and 1400 calories, at least according to the machine. I was always of the mindset that the reason elliptical burns so many calories is because of the foot and arm motion, so I almost never take my hands off the handles except to check heart rate maybe once or twice in the 95 minute workout. I'm just wondering if anyone else has any thoughts in regards to the validity of the elliptical when it comes to calorie count. By the way, the elliptical I use is a PRECOR AMT.

    I noticed the bolded after my initial posts. This could easily bring the calorie burn into the realm of the more average user.

    10 miles at max resistance is a big deal. 900-1000 is probably more likely, and yes. 65 vs 95 minutes certainly matters

    I didn't notice the time discrepancy at first, so I assumed others might have missed it as well. But in either case, being the cardio background the OP stated, I give benefit of the doubt. I've cracked 1000+ per hour on an elliptical, and I know plenty of people more fit than myself. As for "big deal", I see that as subjective. A big deal to a couch potato is a brisk walk, where as a big deal to a quick and accomplished endurance athlete could be at or well above OPs stated calorie burn.

    As for the resistance level, keep in mind max resistance doesn't equal max power. It's still impacted by stride rate, vertical rate, and stride distance. The AMT uses a different generator than my machine, with a lower power max, so higher resistance setting wouldn't be as big of a factor.
  • Heather4448
    Heather4448 Posts: 908 Member
    Why not address the foot pain so you can get back to running? See a sport’s doctor or PT.
This discussion has been closed.