Is it really OK to eat back your workout calories?

24

Replies

  • malibu927
    malibu927 Posts: 17,562 Member
    not ok..

    That’s how the program is set up
  • dmcnur
    dmcnur Posts: 157 Member
    I generally eat some, but not all, back as I find the calories allocated to an activity seem to be over generous at times.
  • amusedmonkey
    amusedmonkey Posts: 10,330 Member
    I don't believe that I am overestimating calorie burn or underestimating calorie intake. ALL of my calorie burn data comes from my Fitbit Charge 2. ALL of my calorie intake comes from religiously weighing/measuring all food and liquids using label data or the MFP database. Not sure what else I could do. I think there are just a lot of inaccuracies in Fitbits, label data and MFP's database. So I would continue to recommend to anybody that over the long haul, don't assume you can eat all of your exercise calories if you want to lose weight. These days there is a strong incentive for food makers to fudge their numbers and little real regulation.

    I downgraded from Charge to Alta because heart rate measurements over-estimated my calorie burn by a lot to where adjusting the calories it gives me to align with my actual loss required ridiculous measures like making myself 4 feet short in Fitbit settings and even then it was inconsistent. Could it be that the way your heart rate responds to things is as overblown as mine? I currently wear my Alta clipped to my bra (wanted to wear a nice watch) and I have myself set as slightly older on Fitbit but at my actual height, and the extra calories I'm getting are on point. I eat every single one of them and lose at my desired rate. You could fiddle with your height and age to adjust the extra calories you get from Fitbit.
  • Xkmaf2018X
    Xkmaf2018X Posts: 97 Member
    Thanks all for your responses, I think from now on (like yesterday) I’ll just eat 50% of my workout calories that fitbit gives me as eating back 50%-75% seems to be what others do.

    I put I was sendetary because I have an office job, my steps come from the walking to school, work, gym, steps throughout the day etc and I gain steps when I do my gym classes too. My step goal is 8k but I tend to do more like 10k.

    Your responses have been a great read - thanks
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    ALL of my calorie burn data comes from my Fitbit Charge 2.

    Just because it's a piece of technology doesn't mean that the data are correct. If you're using it to measure something that is not designed for then you've got an error.

    Would you use a 12 inch rule to measure the volume of water in a fish tank?
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    smolmaus wrote: »
    ALL of my calorie burn data comes from my Fitbit Charge 2.

    Would you use a 12 inch rule to measure the volume of water in a fish tank?

    I don't disagree with your larger point that gadget calorie burns should be taken with a pinch of salt but yeah I would actually, if it was a regular shape lol

    That would give you capacity ( +/-) not content.

    And fwiw I'd apply more than a pinch of salt to a Charge. I'd assume +/-50% error.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Yes, sort of.

    But not really.

    Let's say you and a "very fit" person of approximately your height and weight do 2 hours of light running. you manage 7 miles. the Very fit person cranks out 12.

    Each of your Fitbits estimates 1200 calories for the 2 hours of running. You eat half of your estimated 1200 calories or 600 calories. the "very fit" person eats all 1200. Spitballing 100 calories per mile, you actually burned 700 where the "very fit person actually burned 1200.

    But that's a very extreme and edge example of how and why the same device with the same algorithm gives one person good data and one person less useful data.
  • mutantspicy
    mutantspicy Posts: 624 Member
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Yes, sort of.

    But not really.

    Let's say you and a "very fit" person of approximately your height and weight do 2 hours of light running. you manage 7 miles. the Very fit person cranks out 12.

    Each of your Fitbits estimates 1200 calories for the 2 hours of running. You eat half of your estimated 1200 calories or 600 calories. the "very fit" person eats all 1200. Spitballing 100 calories per mile, you actually burned 700 where the "very fit person actually burned 1200.

    But that's a very extreme and edge example of how and why the same device with the same algorithm gives one person good data and one person less useful data.

    Ok this makes a lot of sense, based on the way these things are currently calculated. If take my dog for a long 4or5 mile walk, I'm being leisurely and not exerting myself, yet the tracker will estimate some really huge amount of calories. I do like keeping track of my steps every day, as for a measure of overall activity level. But I really don't feel like it should be used when determining make up calories. Well at least if you pick light active or active, maybe you would use some of that if you selected sedentary.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Yes, sort of.

    But not really.

    Let's say you and a "very fit" person of approximately your height and weight do 2 hours of light running. you manage 7 miles. the Very fit person cranks out 12.

    Each of your Fitbits estimates 1200 calories for the 2 hours of running. You eat half of your estimated 1200 calories or 600 calories. the "very fit" person eats all 1200. Spitballing 100 calories per mile, you actually burned 700 where the "very fit person actually burned 1200.

    But that's a very extreme and edge example of how and why the same device with the same algorithm gives one person good data and one person less useful data.

    Ok this makes a lot of sense, based on the way these things are currently calculated. If take my dog for a long 4or5 mile walk, I'm being leisurely and not exerting myself, yet the tracker will estimate some really huge amount of calories. I do like keeping track of my steps every day, as for a measure of overall activity level. But I really don't feel like it should be used when determining make up calories. Well at least if you pick light active or active, maybe you would use some of that if you selected sedentary.

    The other variable-Between, not within trackers is whether or not the calculator includes or discounts BMR calories. I'm 230 lbs I burn 100-120 calories an hour sitting on my butt.

    MFP already knows that, so if the estimator says 800 and includes those calories vs 650 and discounts them, that will also introduce error.
  • mutantspicy
    mutantspicy Posts: 624 Member
    edited April 2018
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.
  • okange777
    okange777 Posts: 2 Member
    Feel free to add me, I am new on this site and need all the motivation I can get!
  • janejellyroll
    janejellyroll Posts: 25,763 Member
    I don't believe that I am overestimating calorie burn or underestimating calorie intake. ALL of my calorie burn data comes from my Fitbit Charge 2. ALL of my calorie intake comes from religiously weighing/measuring all food and liquids using label data or the MFP database. Not sure what else I could do. I think there are just a lot of inaccuracies in Fitbits, label data and MFP's database. So I would continue to recommend to anybody that over the long haul, don't assume you can eat all of your exercise calories if you want to lose weight. These days there is a strong incentive for food makers to fudge their numbers and little real regulation.

    Why would you assume that your Fitbit Charge 2 is providing you with an accurate calorie burn? While some people find them to be quite accurate, some people also find that it overestimates their calories burnt.

    The concept that you're burning, say, 200 calories but your body somehow can't add that to an overall deficit doesn't make sense. Your argument is basically that you're burning a certain number of calories but they don't "count."

    A Fitbit is no different than any other method of estimating calorie burn. If your real life observations show you that it isn't accurate, you'll have to adjust until you see the results you want.
  • erickirb
    erickirb Posts: 12,294 Member

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).

    I agree with this, unless your HRM also allows you to change your V02Max and max heart rate. The V02max change will balance out the work performed based on level of fitness, though can still be off for both populations, but this would "equal the playing field"
  • stanmann571
    stanmann571 Posts: 5,727 Member
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.

    The biggest issue, IMO is that all of the algorithms are proprietary, and consequently impossible to evaluate other than on a per user.... AKA "Is this working for me" I've been 100% successful(barring laziness in logging) in using the Garmin/Misfit generated caloric burns as a basis for eating back calories and losing weight. Others have been less successful. It appears that the further you get from running/walking and GPS as a metric, the more likely you will be to have a variation between accurate estimation and inaccurate estimation. For cyclists, a quality power meter that has been correctly calibrated is even better.
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.

    I don't think we are talking about different things, but I think we're approaching it from slightly different directions.

    Tracking devices measure one thing, and extrapolate an estimation of energy expended based on that. If one understands how the metric measured relates to energy consumed then one can account for potential error.

    HR is one of a number of metrics that can be tracked, but it's not a particularly good proxy for energy consumption. Too many things affect it.

    More sophisticated devices do use HR data to corroborate other data, leading to a better approximation. I would agree that the maths is complex. One of my Master's degrees is in control systems.
  • Xkmaf2018X
    Xkmaf2018X Posts: 97 Member
    @WinoGelato

    Thanks for your response, I'm pretty similar to you when you first started your MFP journey, I am 155lbs and 5ft3inches....I am going to stop feeling so bad at eating some of my workout calories back. I put sedentary as I thought that was the norm for people with an office job, I didn't realise it took into account your actual steps etc and like I mentioned I get in around 10k steps per day.

    For now I am going to stick with the 1200 but eat 50% of my workout calories back if I want them and see how I get on.

  • mutantspicy
    mutantspicy Posts: 624 Member
    edited April 2018
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.

    I don't think we are talking about different things, but I think we're approaching it from slightly different directions.

    Tracking devices measure one thing, and extrapolate an estimation of energy expended based on that. If one understands how the metric measured relates to energy consumed then one can account for potential error.

    HR is one of a number of metrics that can be tracked, but it's not a particularly good proxy for energy consumption. Too many things affect it.

    More sophisticated devices do use HR data to corroborate other data, leading to a better approximation. I would agree that the maths is complex. One of my Master's degrees is in control systems.

    Just to clarify, my issue it seems is that some of you seem to be directly correlating Calories to Physical Work.
    That's not real. The Physical work required to lift an 80 lb weight 4 ft off the ground, can be easily calculated without error or question. The amount of thermal energy a human needs to expend to do the work is where the complication begins. So when someone says, it takes so many calories to walk a mile, that's based on empirical data for an average human not physics.

    But I will agree HR data by itself is not the best way to estimate calories, which is kinda what I've been trying to say. Just not so succinctly. :) Anyway, Its an interesting topic.
  • stanmann571
    stanmann571 Posts: 5,727 Member
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.

    I don't think we are talking about different things, but I think we're approaching it from slightly different directions.

    Tracking devices measure one thing, and extrapolate an estimation of energy expended based on that. If one understands how the metric measured relates to energy consumed then one can account for potential error.

    HR is one of a number of metrics that can be tracked, but it's not a particularly good proxy for energy consumption. Too many things affect it.

    More sophisticated devices do use HR data to corroborate other data, leading to a better approximation. I would agree that the maths is complex. One of my Master's degrees is in control systems.

    Just to clarify, my issue it seems is that some of you seem to be directly correlating Calories to Physical Work.
    That's not real. The Physical work required to lift an 80 lb weight 4 ft off the ground, can be easily calculated without error or question. The amount of thermal energy a human needs to expend to do the work is where the complication begins. So when someone says, it takes so many calories to walk a mile, that's based on empirical data for an average human not physics.

    Yes, sort of, If the person uses a particular technique perfectly. But most people don't. There are also efficiencies and inefficiencies involved.

    For a 6 foot tall man, 4 feet is just above waist height meaning he can move that 80 lb weight very efficiently.

    For a 5'2" woman that's just below her chin. There are major inefficiencies that she will suffer.

    For a repeated activity that's also one we are neuromuscularly adapted to(walking). over the course of 15 minutes and .75-1.25 miles, those elements average out and become predictable for the broader population.
  • mutantspicy
    mutantspicy Posts: 624 Member
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.

    The biggest issue, IMO is that all of the algorithms are proprietary, and consequently impossible to evaluate other than on a per user.... AKA "Is this working for me" I've been 100% successful(barring laziness in logging) in using the Garmin/Misfit generated caloric burns as a basis for eating back calories and losing weight. Others have been less successful. It appears that the further you get from running/walking and GPS as a metric, the more likely you will be to have a variation between accurate estimation and inaccurate estimation. For cyclists, a quality power meter that has been correctly calibrated is even better.

    Completely Agree!
  • Jruzer
    Jruzer Posts: 3,501 Member
    smolmaus wrote: »
    ALL of my calorie burn data comes from my Fitbit Charge 2.

    Would you use a 12 inch rule to measure the volume of water in a fish tank?

    I don't disagree with your larger point that gadget calorie burns should be taken with a pinch of salt but yeah I would actually, if it was a regular shape lol

    OT, I know, but this made me laugh! I would do the same. Cubic inches is a perfectly good unit of volume.
  • MeanderingMammal
    MeanderingMammal Posts: 7,866 Member
    edited April 2018
    AnnPT77 wrote: »
    cwolfman13 wrote: »
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Actually, the more fit you are, the more calories you're going to burn because you'll actually go further and go harder.

    It also depends on what your exercise is...determining exercise expenditure from things like boot camps or classes or lifting, etc is difficult...figuring out calories for running and walking is very straight forward. I always used my Garmin bike computer calorie burns minus my basal calories when i was doing the MFP method and I ate around 2300 - 2500 calories per day to lose about 1 Lb per week on average. A power meter on a bike is very accurate.

    There are ways of more accurately determining energy expenditure. But really, the problem in most cases is that people are really bad at estimating both calories coming in and out which is why they have issues.

    I agree with you for the most part, I probably wasn't clear. I was referring the way fitness trackers guestimate our expenditure not our actual expenditure. People with more muscle and endurance and more strength do more. No doubt. Just wondering if fitness trackers have a tendency to over estimate for people are in better condition, because even though they use heart rate, there is still a lot mathematical algorithms behind it all.

    Any of the devices are estimating. Work, in pretty much the physics sense of the term, determines calorie burn. The devices use algorithms based on formulas from research, plus various proxy measures (heart rate, distance, speed, body weight, etc.) to estimate work and therefore calories.

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).
    For instance my average step count is about 17000 to 25000, and I'll get up to 900 calories for that. That just seems crazy to me. Based on my experience I need 1900 cal a day to lose weight. Not 2800 to 3000, I'm not an NFL player. If I actually put mapmyfitness on it will tell something 450 cal for 4 mile walk. And then give me about the same for 40 mins of intense weight lifting. The weight lifting seems more accurate than the walking to me. But really I think they're both pretty high. And my food diary is on point, btw. Its easy to make errant selection, I constantly audit it, import online recipes I use audit them tweak them. I don't pick stuff thats close enough. MFP is solid. Its the trackers that are off.

    ...aren't calories are a thermal unit from heat released due to internal energy expenditure. If you . very helpful

    No. A calorie is just a unit of energy. It's quantified against a thermal energy benchmark, but it's an extensible metric.

    The issue in this area is how does one measure work in a meaningful way. For running and walking it's really easy; distance and mass. For cycling and rowing, measure power output and extrapolate from there.

    If your using the wrong tool to measure something then errors are inevitable.

    I think we are talking about two different things. Some of the Algorithms are just converting how many estimated calories it would take to do a certain amount of physical work (Joules) this can be expressed in Cals. however, Cal are the also the amount of internal thermal energy to burn off a certain amount of water or fat. This is whole theory behind MET/BMR. HRM calorie trackers are attempting estimate your change in temporary metabolic rate due to exercise (heart rate) as where other ones are just estimating the amount of work that needs to be done. And some try to combine the two with some complex math.

    I don't think we are talking about different things, but I think we're approaching it from slightly different directions.

    Tracking devices measure one thing, and extrapolate an estimation of energy expended based on that. If one understands how the metric measured relates to energy consumed then one can account for potential error.

    HR is one of a number of metrics that can be tracked, but it's not a particularly good proxy for energy consumption. Too many things affect it.

    More sophisticated devices do use HR data to corroborate other data, leading to a better approximation. I would agree that the maths is complex. One of my Master's degrees is in control systems.

    Just to clarify, my issue it seems is that some of you seem to be directly correlating Calories to Physical Work.
    That's not real. The Physical work required to lift an 80 lb weight 4 ft off the ground, can be easily calculated without error or question. The amount of thermal energy a human needs to expend to do the work is where the complication begins. So when someone says, it takes so many calories to walk a mile, that's based on empirical data for an average human not physics.

    But I will agree HR data by itself is not the best way to estimate calories, which is kinda what I've been trying to say. Just not so succinctly. :) Anyway, Its an interesting topic.

    It sounds as if you're on about efficiency coefficients?

    The materiality isn't significant enough to worry about. For example running consumes about twice the energy of walking. The fact that as an experienced runner my efficiency coefficients may be 0.5999, whereas someone else might be 0.6002 isn't going to make a material enough difference to worry about.

    And fwiw a calorie is merely a unit of energy, a measure of work done. It doesn't gain some special property when we use it to describe the conversion of chemical energy to thermal and kinetic energy.
  • AnnPT77
    AnnPT77 Posts: 34,598 Member
    I have always found that if I eat all of my exercise calories, I won't lose weight despite my best efforts to accurately determine calories consumed. Past discussions of this issue here indicated that a lot of others found the same results as I have. If I keep it to eating half or less of the exercise calories I will lose weight. The mathematics just don't seem to fit with the biology. I think some of the reasons for this is that in eating more of the exercise calories a person is likely to have consumed more fat calories and/or more sodium resulting in water weight gain. I'm not a dietitian and maybe we could hear from someone who is that might have a better explanation.

    Same for me. I wonder if it has to do with fitness level. Like if you're heart, lungs, muscle are used to working out for years and years. Maybe the calorie burn is a lot less, than for someone who is out of shape. I know they're supposed to take that into account, but I just feel like the numbers for me are highly inflated. On average I burn over 1200 cals a day from steps and workouts, If ate that back I'd get fat quick.

    Yes, sort of.

    But not really.

    Let's say you and a "very fit" person of approximately your height and weight do 2 hours of light running. you manage 7 miles. the Very fit person cranks out 12.

    Each of your Fitbits estimates 1200 calories for the 2 hours of running. You eat half of your estimated 1200 calories or 600 calories. the "very fit" person eats all 1200. Spitballing 100 calories per mile, you actually burned 700 where the "very fit person actually burned 1200.

    But that's a very extreme and edge example of how and why the same device with the same algorithm gives one person good data and one person less useful data.

    Ok this makes a lot of sense, based on the way these things are currently calculated. If take my dog for a long 4or5 mile walk, I'm being leisurely and not exerting myself, yet the tracker will estimate some really huge amount of calories. I do like keeping track of my steps every day, as for a measure of overall activity level. But I really don't feel like it should be used when determining make up calories. Well at least if you pick light active or active, maybe you would use some of that if you selected sedentary.

    If you walk 5 miles, the calorie burn is about the same, regardless of whether you go faster (exert yourself) or slower (leisurely, stay cool). I think you're over-inflating the importance of how hot you get. How hot you get doesn't really matter much.

    The calories per hour are very different for a fast 5 miles, as @stanmann571's example illustrates. But if his example used two people of the same size but different fitness levels, and had them each run for 5 miles, they'd burn about the same number of calories, but take different amounts of time to finish the distance.
  • NorthCascades
    NorthCascades Posts: 10,968 Member
    erickirb wrote: »

    IMO, a heart-rate-based device is more likely to underestimate calories for an above-average fit person, and overestimate calories for a very unfit person. Why? Because I suspect the algorithms are pitched to average fitness, and a very fit person will perform work X with a lower than average heart rate (look like they're doing less work), while a very unfit person will spike their heart rate doing the same X work (look like they're doing more work).

    I agree with this, unless your HRM also allows you to change your V02Max and max heart rate. The V02max change will balance out the work performed based on level of fitness, though can still be off for both populations, but this would "equal the playing field"

    This only makes sense if you know your current VO2max for the activity in question. And even then it'll leave you with a giant margin of error.
This discussion has been closed.