If exercise calculators aren't accurate and HRMs aren't accurate, then what the heck is?!?
Replies
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Everything is an estimate.
Have you checked how accurate your scale is? Put a 10kg weight on there to make sure it actually reads 10kg?
For me a slightly inaccurate estimate beats guessing.
Just to throw one more wrench in the works, how do you know that a 10kg weight actually weighs 10kg? Is your scale wrong, or is the weight lighter/heavier than it claims to be?*
* Not that it matters. All that matters is if the overall trend is downward, daily/weekly fluctuations notwithstanding. Who cares if your actual weight is 157 lbs. or 159 lbs.? What matters is that whatever weight is shown on the scale is progressively trending lower over time.
Fill a 2 litre bottle with water and put that on the scale. Should read 2 kg.
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emmylootwo wrote: »Getting really annoyed...
I'm looking into purchasing a new Polar heart rate monitor with a chest strap. I understand that calculators such as the one on MFP and other websites (as well as on machines like a treadmill) are not accurate and tend to overestimate. I did some searching in previous discussions on MFP, however, and found plenty of comments saying that an HRM with a chest strap was also inaccurate, especially for anything other than steady state cardio. So, 1.) What counts as steady state cardio? I know this doesn't include strength training but my HRM can't even handle a workout video? Or anything with any sort of intervals? And 2.) If online calculators do not give reasonable estimates of calories that I can safely use to eat back on MFP and neither does an HRM, then what the heck does? Is MFPs entire premise of eating back exercise calories just a total sham? Even if I were to eat back 25-50% of exercise calories, who's to say that still not an overestimation?
Exactly OP! and that is why I don't have/want a fitness tracker and I don't eat my exercises calories unless I am hungry or losing more weight.
If the scale gives me a satisfactory number and my clothes fit good, I am happy camper.
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Everything is an estimate.
Have you checked how accurate your scale is? Put a 10kg weight on there to make sure it actually reads 10kg?
For me a slightly inaccurate estimate beats guessing.
Just to throw one more wrench in the works, how do you know that a 10kg weight actually weighs 10kg? Is your scale wrong, or is the weight lighter/heavier than it claims to be?*
* Not that it matters. All that matters is if the overall trend is downward, daily/weekly fluctuations notwithstanding. Who cares if your actual weight is 157 lbs. or 159 lbs.? What matters is that whatever weight is shown on the scale is progressively trending lower over time.
Fill a 2 litre bottle with water and put that on the scale. Should read 2 kg.
That's what I was going to suggest.
But how do you know the bottle is accurate?
And around and around we go
But like it was said early, doesn't matter, just look at trends over time.0 -
Just to throw one more wrench in the works, how do you know that a 10kg weight actually weighs 10kg?
If it's an actual calibrated weight then it was weighed on a scale which is itself regularly calibrated with reference to international weight standards. Your home scale, on the other hand, may not have been properly calibrated when it was made (this is the maybe difference between cheap scales and good ones), and even if it was, has probably wanderedsincethen, as all scales do. So a calibrated weight will be much more accurate than your own scale.
If you want a really accurate weight, use water in a lightweight container that you can easily calculate the volume of. One cubic centimetre of fresh water weighs a gram. Of course, the container itself is a source of error, but how accurate are we trying to be here? I personally don't bother checking the scale, I just always use the same one so the error is constant.
OP, one thing to remember is that when you are taking a lot of inaccurate estimates and combining them, quite a lot of the errors will cancel out. I think you're imagining a big cumulative error which will cause you to drastically over- or underestimate calories, but unless there is a specific reason for the errors to all lie in one direction, it's not that likely to happen that way. If it does, you'll see it in your weight loss, which will stall or be too rapid.
But in general, a large number of small guesses can give a surprisingly accurate final result.
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emmylootwo wrote: »Thanks all. I guess I am little too anal retentive over the numbers. I weigh and I log all my food down to the gram, and it feels almost like an exact science, although I realize it's not. And then I try to log my exercise, and one calculator says I burn 300 calories, another says I burn 150. If the inaccuracies of not weighing your food can eat up your week's deficit, just imagine what would happen if you also had an inaccurate exercise calorie estimate! I understand that everything is an estimate, but it would be nice to know that at least one of those estimates is close to the truth... I don't know which one to believe. I have used an HRM in the past and relied on it's estimates, although I never ate any of the exercise calories back as I should have. It's frustrating to now find out that the HRM wasn't as accurate as I thought it was. Here I was imagining that the HRM could tell how many calories your body was burning based on how fast your heart was beating! Ooops.
Thanks for the advice everyone.
Regarding the bold - go on then, let's imagine what would be the result.....
Assuming your food logging is accurate (pre-packaged foods are allowed a significant variance, fresh ingredients aren't at all uniform in calories.....).
Assume that your RMR estimate is accurate (to what degree for you? It's a population average).
Assume that your activity setting is accurate (it's not just your average activity over a period of time, it's a population average).
And then assume your HRM, or machine, or formula, or METS table, or guesstimate of your exercise expenditure is out by 150 cals or so.
And then let's assume it's an over estimate not an under estimate (contrary to popular opinion under estimates also happen!).
Maybe you do that exercise three times a week and your over estimate comes to 500 cals a week variance.
So approximately every seven weeks you lose about 1lb less than you expected.
After all that is that really such a big deal?
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emmylootwo wrote: »Thanks all. I guess I am little too anal retentive over the numbers. I weigh and I log all my food down to the gram, and it feels almost like an exact science, although I realize it's not. And then I try to log my exercise, and one calculator says I burn 300 calories, another says I burn 150. If the inaccuracies of not weighing your food can eat up your week's deficit, just imagine what would happen if you also had an inaccurate exercise calorie estimate! I understand that everything is an estimate, but it would be nice to know that at least one of those estimates is close to the truth... I don't know which one to believe. I have used an HRM in the past and relied on it's estimates, although I never ate any of the exercise calories back as I should have. It's frustrating to now find out that the HRM wasn't as accurate as I thought it was. Here I was imagining that the HRM could tell how many calories your body was burning based on how fast your heart was beating! Ooops.
Thanks for the advice everyone.
I guarantee you I am highly anal retentive about the math and the numbers. (Heck, I wrote a data analysis package for this - see my profile's first link.) I also have several HRMs, GPS units and bike computers. I like data.
However, here is a method, where the actual exercise calorie estimates don't matter.
Just control what you eat, exercise regularly and eat an estimate extra of say 200 cals per 1hr session, track weight loss. If weight loss is larger than expected eat more cals. Adjust.5 -
EvgeniZyntx wrote: »emmylootwo wrote: »Thanks all. I guess I am little too anal retentive over the numbers. I weigh and I log all my food down to the gram, and it feels almost like an exact science, although I realize it's not. And then I try to log my exercise, and one calculator says I burn 300 calories, another says I burn 150. If the inaccuracies of not weighing your food can eat up your week's deficit, just imagine what would happen if you also had an inaccurate exercise calorie estimate! I understand that everything is an estimate, but it would be nice to know that at least one of those estimates is close to the truth... I don't know which one to believe. I have used an HRM in the past and relied on it's estimates, although I never ate any of the exercise calories back as I should have. It's frustrating to now find out that the HRM wasn't as accurate as I thought it was. Here I was imagining that the HRM could tell how many calories your body was burning based on how fast your heart was beating! Ooops.
Thanks for the advice everyone.
I guarantee you I am highly anal retentive about the math and the numbers. (Heck, I wrote a data analysis package for this - see my profile's first link.) I also have several HRMs, GPS units and bike computers. I like data.
However, here is a method, where the actual exercise calorie estimates don't matter.
Just control what you eat, exercise regularly and eat an estimate extra of say 200 cals per 1hr session, track weight loss. If weight loss is larger than expected eat more cals. Adjust.
I am also a data person ... been working with databases for years, slogging my way toward a masters in IT specialising in databases (not the program's exact title).
And personally, I've kept a log of every single kilometre I've cycled since April 29, 1990.
But I agree ... just make your best guess estimates, stick with it absolutely and completely for a month ... and see where you are at the end of the month. That's all I did and I've lost my weight.- I weighed most of my food, although I do go with the calories on the package if that's available.
- I've logged meticulously, consistently and regularly during the weeks I've been on the diet (16 weeks on, 1 month off, 16 weeks on, 6 weeks off, etc.), and I do not go over my calories when I'm on the diet.
- I do eat some or all of my exercise calories back depending on how much exercise I've done, or how hungry I am, or if I want to speed up the process a little or whatever.
- I'm a cyclist, so I use the formula 100 cal for every 5 kilometres.
- I walk and I log approx. 200 cal/hour.
- I climb stairs and according to a chart at the bottom of the stairs in the last place I worked, I burn 6 calories per flight.
- As for the rest of my activity (swimming, kayaking, rowing, running, etc.), I select the "light" or "easy pace" version available on MFP.
- And I don't count walking around the office, walking around at home, standing in meetings, doing housework, walking around grocery stores, walking through parking lots on the way to the grocery store, taking the two flights of stairs to the library, taking the three flights of the stairs to the women's clothing section of one of the local stores, pacing at the bus stop, etc. etc. etc. ... I figure all those little bits and pieces are bonus calories burned to compensate for any miscalculations I might have made along the way.
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Any tracker is just a guideline for calorie burn, they aren't usually too far away but that will change from person to person. You'll know yourself within a few weeks of data of tracking calories/weighing yourself how accurate they are for you and you can adjust calories up/down as necessary.0
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Consistent results over time are accurate. Log your meals and your exercise for 4 weeks. If you are getting the results you want then great. If not adjust your calories and/or exercise from there.
If you tracking is off they'll be off fairly consistently and the error will be offset by the adjustment in calories and/or exercise.0 -
EvgeniZyntx wrote: »emmylootwo wrote: »Thanks all. I guess I am little too anal retentive over the numbers. I weigh and I log all my food down to the gram, and it feels almost like an exact science, although I realize it's not. And then I try to log my exercise, and one calculator says I burn 300 calories, another says I burn 150. If the inaccuracies of not weighing your food can eat up your week's deficit, just imagine what would happen if you also had an inaccurate exercise calorie estimate! I understand that everything is an estimate, but it would be nice to know that at least one of those estimates is close to the truth... I don't know which one to believe. I have used an HRM in the past and relied on it's estimates, although I never ate any of the exercise calories back as I should have. It's frustrating to now find out that the HRM wasn't as accurate as I thought it was. Here I was imagining that the HRM could tell how many calories your body was burning based on how fast your heart was beating! Ooops.
Thanks for the advice everyone.
I guarantee you I am highly anal retentive about the math and the numbers. (Heck, I wrote a data analysis package for this - see my profile's first link.) I also have several HRMs, GPS units and bike computers. I like data.
However, here is a method, where the actual exercise calorie estimates don't matter.
Just control what you eat, exercise regularly and eat an estimate extra of say 200 cals per 1hr session, track weight loss. If weight loss is larger than expected eat more cals. Adjust.
Exactly.
Does anyone have any experience with real-life control systems? You base your feedback model on your understanding of the physical phenomena that drive the system, but you don't base the actual system performance on blind trust that the inputs will affect the output as you expect. You measure the output and you adjust the inputs as needed.2 -
My Garmin watch with chest strap seems accurate enough to me. It's certainly accurate enough to help with pace management, and I'm sure the calorie used estimates are accurate enough to be of some assistance with weight-loss management.0
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emmylootwo wrote: »Thanks all. I guess I am little too anal retentive over the numbers. I weigh and I log all my food down to the gram, and it feels almost like an exact science, although I realize it's not. And then I try to log my exercise, and one calculator says I burn 300 calories, another says I burn 150. If the inaccuracies of not weighing your food can eat up your week's deficit, just imagine what would happen if you also had an inaccurate exercise calorie estimate! I understand that everything is an estimate, but it would be nice to know that at least one of those estimates is close to the truth... I don't know which one to believe. I have used an HRM in the past and relied on it's estimates, although I never ate any of the exercise calories back as I should have. It's frustrating to now find out that the HRM wasn't as accurate as I thought it was. Here I was imagining that the HRM could tell how many calories your body was burning based on how fast your heart was beating! Ooops.
Thanks for the advice everyone.
It'd be nice if it worked that way all of the time, even for SS cardio, but no. Too many factors mess with your heart rate that have nothing to do with the actual energy you're expending for super reliable accuracy, though for most SS cardio an HRM works well enough. It's not as though you really need to-the-calorie accuracy.
Since I don't think anyone answered your question on SS cardio, that'd be any cardio where your intensity doesn't change rapidly. So, intervals would be a problem, though the longer the interval the less of a problem they are. If you do decide to use an HRM, make sure it's properly calibrated for your max HR, etc.0 -
- And I don't count walking around the office, walking around at home, standing in meetings, doing housework, walking around grocery stores, walking through parking lots on the way to the grocery store, taking the two flights of stairs to the library, taking the three flights of the stairs to the women's clothing section of one of the local stores, pacing at the bus stop, etc. etc. etc. ... I figure all those little bits and pieces are bonus calories burned to compensate for any miscalculations I might have made along the way.
^^ This is why I don't use a tracker - I don't want to log all the little things I am trying to make habitual, and I know myself - I would be checking that tracker all day long.
Instead I turn my HRM on when I leave the gym locker room, and turn it off when I walk back in. Then I log those calories and move on. I also give myself 150 calories for the hour I spend with my trainer at a training studio, but I'm not wearing my HRM then and I'm sure sometimes it's more, and sometimes it's less. When I do these things, weigh and log food, and eat at a deficit, I lose.
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You'll know by your own accumulation of data over a period of time what's accurate for you...that is if you chart your weight loss/track cals etc
Although the online calculators are usually never far away iml. I also find FitBit is actually very accurate for me. It's about trial and error in general though.0 -
It is all a crapshoot. Try, measure, adjust. That is the only method that works.0
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BillMcKay1 wrote: »What is accurate? Honestly time and data points. MFP is a tool and really a blunt one at that. I'm finding it useful as a food diary and calorie calculator, but only if time is taken to ensure the products entered are correct.
I started changing up my diet on May 13 and logging here on the 24th. Following the MFP calorie suggestion of 1590 daily and logging exercise calories but only maybe eating back 10%-20% at most. After losing 21lbs since May 13 and 15 in the last 16 days, I'm pretty sure my calories in is too low, even though I'm not finding myself hungry. I don't however really trust the MFP exercise calories numbers.
I'm going to try changing my setting from sedentary, as I have a desk job, to lightly active as I'm powerlifting 3x a week and doing a pretty good 30min uphill walk daily but pretend exercise calories don't exist as theoretically they are already accounted for. Just eat to the next "activity" level suggested at 1850 cals and see what happens over the next couple weeks.
Really only way I can see to get accurate data is use MFP or some other food diary as the raw "input" of calories in and track scale/measurement changes over time to see if that calories in number needs tweaking based on activity levels.
I'm in almost exactly the same position. I started May 10th, same calorie suggestion as you, same eat-back, and same loss. AND I'm also not hungry.
You are really not sedentary. I was reading in another thread where someone found it strange that a user who walked 6,000 steps a day classed themselves as 'sedentary', which really got me thinking. Yes, I do a desk job but I walk 2 hours a day. It's time to lose the sedentary and up the calories.0 -
I should point out that a lot of people who research and purchase tracking devices end up liking the feedback they get from them, whether it's performance monitoring or calorie burn. A lot of those who think, hello? This is just heart rate not calories tend not to buy one, which is completely okay and makes sense! If you think you might find one useful, you should get it. Be familiar with any return policies and get to using it ASAP though lol0
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I read this before I bought my chest strap for my Garmin device.. I did some research and this is older blog sums it up pretty well.
http://www.myfitnesspal.com/blog/Azdak/view/the-real-facts-about-hrms-and-calories-what-you-need-to-know-before-purchasing-an-hrm-or-using-one-21472
And a little more on HRM's and using it for strength training for those interested.
http://www.myfitnesspal.com/blog/Azdak/view/hrms-cannot-count-calories-during-strength-training-176980 -
BillMcKay1 wrote: »What is accurate? Honestly time and data points. MFP is a tool and really a blunt one at that. I'm finding it useful as a food diary and calorie calculator, but only if time is taken to ensure the products entered are correct.
I started changing up my diet on May 13 and logging here on the 24th. Following the MFP calorie suggestion of 1590 daily and logging exercise calories but only maybe eating back 10%-20% at most. After losing 21lbs since May 13 and 15 in the last 16 days, I'm pretty sure my calories in is too low, even though I'm not finding myself hungry. I don't however really trust the MFP exercise calories numbers.
I'm going to try changing my setting from sedentary, as I have a desk job, to lightly active as I'm powerlifting 3x a week and doing a pretty good 30min uphill walk daily but pretend exercise calories don't exist as theoretically they are already accounted for. Just eat to the next "activity" level suggested at 1850 cals and see what happens over the next couple weeks.
Really only way I can see to get accurate data is use MFP or some other food diary as the raw "input" of calories in and track scale/measurement changes over time to see if that calories in number needs tweaking based on activity levels.
I'm in almost exactly the same position. I started May 10th, same calorie suggestion as you, same eat-back, and same loss. AND I'm also not hungry.
You are really not sedentary. I was reading in another thread where someone found it strange that a user who walked 6,000 steps a day classed themselves as 'sedentary', which really got me thinking. Yes, I do a desk job but I walk 2 hours a day. It's time to lose the sedentary and up the calories.
That's a good point I do 14k steps a day but consider myself sedentary because I sit at a desk all day. That said, I still don't lose weight (probably because I binge eat).0
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