Polar HRM calorie burn estimate accuracy - study
Replies
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I have a Polar F7 and have been using it regularily during my workouts. It always shows more calories burned than my fitbit which i wear daily under my clothing.
So now you are saying that my Polar is lying to me?
I don't know how seriously you are using the term "lying", but that's not what is going on.
HRMs are set up to estimate calories expended under certain exercise conditions. Their accuracy depends on:
1. How closely the exercise you are doing matches the assumptions behind the HRM calorie-estimating formula.
2. The accuracy/quality of the calorie-estimating formula itself (not all HRMs are the same--these formulae are proprietary products; this is why people feel that the Polar-brand products are the best--they have better equations than other brands, as do Suunto and some Garmin products).
3. The accuracy of the setup information--that means, as closely as possible, having actual HRmax and VO2max values.
HRMs calorie estimations are given an importance that is vastly disproportionate to their actual value. Why is this?
1. The human capacity for self-BS is unlimited. People WANT to believe in these devices so much.
2. The manufacturers play a kind of shell game with these devices. They don't really claim that they are super accurate, but they imply it with their marketing. It's a classic case of lying by only telling part of the truth. It is instructive to note that, while the calorie-counting feature is probably the #1 reason why the casual exerciser buys an HRM, there is little or no documentation in the user manuals about the feature. You get pages and pages of information on zone training and HR programs, but zippo on the calories or how to make that reading more accurate. Why? Because they know.
3. The other sources of information--many (not all) exercise machines and data tables--are even more inaccurate much of the time.
4. Many fitness people have a fairly shallow understanding of exercise physiology. Since they can't tell the difference themselves, they all too willingly buy into unsupported fitness hype and spread the misinformation themselves.
That being said, the Polar is likely to be more accurate for exercise calories that a fitbit. My experience with a body bugg (which I think is more accurate than a fitbit) is that it was not of much use for estimating exercise calories.0 -
Probably a great tool if the user is aware of its limitations. And I'm sure it can be a huge motivator to see the impact exercise has on fat burn. When I was trying to lose weight, I always tried to run on days that I knew I'd go over my allotted calories. Seeing results from an HRM is confirmation that exercise is an important tool in your weight loss arsenal, and it's impact can be quantified.
Having said that, I never used an HRM. I used calorie burn approximations found on this site. However, I always entered it in conservatively. So a 30 minute jog became a 20 minute jog, etc., etc. I think a similar approach should be employed with HRM readings. Take 75% of the total before entering it. Especially if you're struggling to lose weight and you appear to be meeting your daily net (after exercise) calorie goals, with no results. Overestimating calorie loss from exercising could be a bit part of why you aren't losing weight.
Another cause for overestimation: even if you were sitting on the couch watching TV, you would still be burning calories. And those calories burned by doing next to nothing are already included in MFP net totals. Which is why nobody enters (I hope) "Watching TV for 2 hours: 120 calories burned." So you should subtract what you would have burned doing next to nothing from the total calories you burned by jogging, or whatever other exercise you performed.
--P0 -
Another cause for overestimation: even if you were sitting on the couch watching TV, you would still be burning calories. And those calories burned by doing next to nothing are already included in MFP net totals. Which is why nobody enters (I hope) "Watching TV for 2 hours: 120 calories burned." So you should subtract what you would have burned doing next to nothing from the total calories you burned by jogging, or whatever other exercise you performed.
Oh great, I sense another thread starting with arguments, since the cleaning one always does.
I logged standing up eating over the kitchen sink, or cooking, or shower time, can I eat those calories back?
That would be great to see - watched marathon set of Biggest Loser for 8 hrs - 600 calories. How many should I eat back? Well, I actually watched while eating potato chips.
LOL.0 -
My head hurts!
This ^^
... too... many...words.... and ...numbers..
*falls over*0 -
I have a Polar F7 and have been using it regularily during my workouts. It always shows more calories burned than my fitbit which i wear daily under my clothing.
So now you are saying that my Polar is lying to me?
I don't know how seriously you are using the term "lying", but that's not what is going on.
HRMs are set up to estimate calories expended under certain exercise conditions. Their accuracy depends on:
1. How closely the exercise you are doing matches the assumptions behind the HRM calorie-estimating formula.
2. The accuracy/quality of the calorie-estimating formula itself (not all HRMs are the same--these formulae are proprietary products; this is why people feel that the Polar-brand products are the best--they have better equations than other brands, as do Suunto and some Garmin products).
3. The accuracy of the setup information--that means, as closely as possible, having actual HRmax and VO2max values.
HRMs calorie estimations are given an importance that is vastly disproportionate to their actual value. Why is this?
1. The human capacity for self-BS is unlimited. People WANT to believe in these devices so much.
2. The manufacturers play a kind of shell game with these devices. They don't really claim that they are super accurate, but they imply it with their marketing. It's a classic case of lying by only telling part of the truth. It is instructive to note that, while the calorie-counting feature is probably the #1 reason why the casual exerciser buys an HRM, there is little or no documentation in the user manuals about the feature. You get pages and pages of information on zone training and HR programs, but zippo on the calories or how to make that reading more accurate. Why? Because they know.
3. The other sources of information--many (not all) exercise machines and data tables--are even more inaccurate much of the time.
4. Many fitness people have a fairly shallow understanding of exercise physiology. Since they can't tell the difference themselves, they all too willingly buy into unsupported fitness hype and spread the misinformation themselves.
That being said, the Polar is likely to be more accurate for exercise calories that a fitbit. My experience with a body bugg (which I think is more accurate than a fitbit) is that it was not of much use for estimating exercise calories.
This should be required reading for anyone wishing to purchase a HRM. Excellent post!0 -
Thought I might piggyback here and see if anyone could help me figure things out.
I had my thyroid gland removed last June. While my recovery from the surgery was swift, I’ve experienced a few physiological changes I’m not thrilled with. Specifically, I have a lower resting heart rate and a lower max heart rate. My resting went from the 70s to the 50s. And where I once successfully maintained an average HR in the 140s and 150s while jogging for instance, it seems now that I’m gasping for air when it’s in the 120s. It’s very hard to get it up high. Does that mean that I am burning fewer calories now doing the same exercise I was doing prior to the thyroidectomy?
I had my RMR tested at a university in May. It came back at 1699. Not bad at all. The nutritionist told me that was slightly less than average for a woman my age and body composition. Yet, regardless of breaking even on cals in v cals out (at least according to BodyMedia—which I’ve since ditched—and Fitbit—which I still wear), I can’t even maintain my weight and have packed on 20 pounds in the last year. All of which is a bit disheartening since at one time I could say I’d lost over 130 pounds and kept it off while averaging around 2200 cals in. I’m having a hard time finding the magic number. I’ve crunched numbers using spreadsheets I’ve found here on MFP and everything keeps pointing to something around 2100. But I fear that may not be work because my HR is lower than “normal.” Despite my endocrinologist trying to tell me my new low resting HR meant I was athletically adept. I’m no Lance Armstrong!
I’ve also had a “cardio coach” session where my VO2Max was determined at different heart rates. So I’ve been using a formula where I plug in my VO2Max number based on my avg HR for that session to figure out calories burned. Is this my best bet for determining cals burned? The numbers are much higher than Fitbit and about 100 or so more than my Polar F7.
PS. I’m a 50 yr old female, 5’10” and currently 235 pounds. And yes, menopause already has one foot in the door! Yet another factor in my poopy sitch.
Any knowledgeable advice is welcome. Thanks in advance.
-Cynthia0 -
Thought I might piggyback here and see if anyone could help me figure things out.
I had my thyroid gland removed last June. While my recovery from the surgery was swift, I’ve experienced a few physiological changes I’m not thrilled with. Specifically, I have a lower resting heart rate and a lower max heart rate. My resting went from the 70s to the 50s. And where I once successfully maintained an average HR in the 140s and 150s while jogging for instance, it seems now that I’m gasping for air when it’s in the 120s. It’s very hard to get it up high. Does that mean that I am burning fewer calories now doing the same exercise I was doing prior to the thyroidectomy?
I had my RMR tested at a university in May. It came back at 1699. Not bad at all. The nutritionist told me that was slightly less than average for a woman my age and body composition. Yet, regardless of breaking even on cals in v cals out (at least according to BodyMedia—which I’ve since ditched—and Fitbit—which I still wear), I can’t even maintain my weight and have packed on 20 pounds in the last year. All of which is a bit disheartening since at one time I could say I’d lost over 130 pounds and kept it off while averaging around 2200 cals in. I’m having a hard time finding the magic number. I’ve crunched numbers using spreadsheets I’ve found here on MFP and everything keeps pointing to something around 2100. But I fear that may not be work because my HR is lower than “normal.” Despite my endocrinologist trying to tell me my new low resting HR meant I was athletically adept. I’m no Lance Armstrong!
I’ve also had a “cardio coach” session where my VO2Max was determined at different heart rates. So I’ve been using a formula where I plug in my VO2Max number based on my avg HR for that session to figure out calories burned. Is this my best bet for determining cals burned? The numbers are much higher than Fitbit and about 100 or so more than my Polar F7.
PS. I’m a 50 yr old female, 5’10” and currently 235 pounds. And yes, menopause already has one foot in the door! Yet another factor in my poopy sitch.
Never heard the medical term "poopy sitch"! Ha. Glad you made it out of the surgery and kept going.
You can lose cardiorespiratory fitness, if you mean this last past June, and recent observation. If you mean last year, and you've as a good as normal routine, then that is a change.
Now, the surgery may have just kicked off early and suddenly a change that was going to happen anyway, the shock to the system. My metabolism really seemed to change after a shoulder surgery in early 20's, Dr said that wasn't unusual, and I may or may not get back to previous. Lovely. Hair started falling out early too, though that was going to happen eventually too.
You may be burning fewer calories at rest and sleep, but activity the only lowering would be from being more fit, so slight decrease there. But really, it takes so much energy to move so much mass in certain ways, where your HR is just means you burned certain ratio carbs:fat, and how fit you are.
If you are gasping for air, it's just as hard an effort. Just confirm you lower the HRM stat for HRmax so you have an idea where you are. Just means you have a lower range, that's all.
That formula using VO2max is going to be pretty good, it's based on a study paid for by Polar after all. And they will be higher than FitBit and even Polar, which has to estimate what your VO2max may be to use similar formula.
http://www.braydenwm.com/calburn.htm
And here is a spreadsheet where you can put in your stats, AND your tested RMR, and base info on that. And with calculated workout calories, even figure out your better TDEE estimate based on that, to take a deficit to. Don't slow down that high RMR.
And HRM tab to see if your VO2max is better or worse than calculated.
http://www.myfitnesspal.com/topics/show/717858-spreadsheet-bmr-tdee-and-deficit-calcs-macros-hrm
Oh yeah, the FitBit and BodyMedia, are basing the foundation of their estimates on age, weight, height BMR, and from your RMR you are about 220 below that. So they would be overestimating daily activity which they can at least be more accurate with, but in that case may actually be right for real exercise.0 -
Bump0
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When I first got my HRM, I didn't know much about them, other than reading this forums gave me the idea that they are more accurate than other methods of determining calorie burn. I remember reading something about VO2 max but since I didn't understand I didn't go out of my way to get a more expensive HRM (although my Polar FT7 is not cheap by my standards). I was under the impression that you could input MaxHR or VO2 Max into it but I am apparently wrong. So far it has not been a problem, luckily. The algorithm used seems to be working for me (has for ~ 6 months).
However, I did find somewhere on these forums the info that the algorithm COULD be wrong and that you can fix it by using (it was either a website or a spreadsheet) whatever this person posted to figure out what age you could input into your Polar to change the MaxHR. Unfortunately, I have no idea where that post is anymore. Between the power getting shut down with the hurricane and my husband closing my websites, it isn't open in my tabs anymore. But with a bit of searching, if you are so inclined, I'm sure one could find it and "fix" their HRM if they feel that the calorie burn is inaccurate.
Thanks everyone for the informative posts (OP and other subsequent posters who also had backed up research)!
Edit: Yay! Found the post!
http://www.myfitnesspal.com/topics/show/466973-i-want-to-test-for-my-max-heart-rate-vo2-max0 -
I'll be getting Polar FT7 in the next couple of days, so BUMP0
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Thanks for posting this
great info.
I was talking to some one about measuring fat using scales and how inaccurate that was. BUT it is reliable to see an upwards or downwards difference. So if you are just looking at it to measure a reduction not an actual figure then that would be ok.0 -
Thanks for posting this great info.
I was talking to some one about measuring fat using scales and how inaccurate that was. BUT it is reliable to see an upwards or downwards difference. So if you are just looking at it to measure a reduction not an actual figure then that would be ok.
Some of the can be very consistent indeed, which is what you need for trend direction.
Most really require the user to be consistent too with how they use it.
My morning after a rest day where I'm not still sore and retaining water is very infrequent, so I don't even try it seems.0 -
Finally found another location of the study.
http://journals.lww.com/acsm-msse/pages/articleviewer.aspx?year=2004&issue=08000&article=00024&type=abstract
Full article.
http://www.setantacollege.com/wp-content/uploads/Journal_db/Accuracy of Polar S410 Heart Rate Monitor.pdf0 -
So in layman's terms, my FT7 is giving me the wrong results in terms of calories burnt?
That's disappointing.
It might be wrong, but it is 'directionally correct'. Using its values and the HR element during training will help you understand your body and fine tune your exercise and nutrition.
Remember, your scale isn't accurate either but it helps you monitor the trends, right? Same for the calorie burn on HRM. I discount mine by 30%. Always ensures deficit. My scale, in conjunction with HRM, helps me manage weight and fitness.
I LIVE by the HR element during cardio, making sure that i hit each HR zone for the desired amount of time and dont slack off, which i some times like to do....
Even if inaccurate, it is still your freind!
LOVE the HRM!!!
Good luck!0 -
So in layman's terms, my FT7 is giving me the wrong results in terms of calories burnt?
That's disappointing.
It might be wrong, but it is 'directionally correct'. Using its values and the HR element during training will help you understand your body and fine tune your exercise and nutrition.
Remember, your scale isn't accurate either but it helps you monitor the trends, right? Same for the calorie burn on HRM. I discount mine by 30%. Always ensures deficit. My scale, in conjunction with HRM, helps me manage weight and fitness.
I LIVE by the HR element during cardio, making sure that i hit each HR zone for the desired amount of time and dont slack off, which i some times like to do....
Even if inaccurate, it is still your freind!
LOVE the HRM!!!
Good luck!
True, and you are actually using it for it's original and intended and best purpose - monitoring HR.
And making exercise choices based on that.
So many though say you must improve MFP's calorie counts by getting a HRM, without realizing the limits of the tool.0 -
So in layman's terms, my FT7 is giving me the wrong results in terms of calories burnt?
That's disappointing.
It might be wrong, but it is 'directionally correct'. Using its values and the HR element during training will help you understand your body and fine tune your exercise and nutrition.
Remember, your scale isn't accurate either but it helps you monitor the trends, right? Same for the calorie burn on HRM. I discount mine by 30%. Always ensures deficit. My scale, in conjunction with HRM, helps me manage weight and fitness.
I LIVE by the HR element during cardio, making sure that i hit each HR zone for the desired amount of time and dont slack off, which i some times like to do....
Even if inaccurate, it is still your freind!
LOVE the HRM!!!
Good luck!
True, and you are actually using it for it's original and intended and best purpose - monitoring HR.
And making exercise choices based on that.
So many though say you must improve MFP's calorie counts by getting a HRM, without realizing the limits of the tool.
Correct. We all have to adjust MFP if we are serious as MFP is very general (there are only 4 levels of activity? (I am semi-sedentary!!).
The best tool is your own body. The other stuff (bathroom scales, calipers, food scales, HRM, etc) are all part of the supporting cast. No one tool works exclusively. however, in concert with each other, they can help you can learn a lot about you and your body and make some amazing changes.
Good luck!0 -
bump0
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bumpity bump.
Thanks Mike , You are always so Knowledgeable and helpful!0 -
Bump for later0
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I guess I should have thrown the solution in there to obtain the better accuracy. Though you still may want to subtract 12%.
It's the default calculations based on avg's that cause the biggest inaccuracy.
If you can find out your own figures for max HR, and if your monitor lets you do it, VO2 max, you can greatly improve the accuracy.
For VO2 max estimate:
http://www.brianmac.co.uk/queens.htm
Here is a submaximal test to estimate your max HR, if you feel like doing the true killer test (and serious, be fit already to do that one), you can find it at the above site.
. The SubMax Step Test. Use an 8" step (almost any step in your home or in a club will do) and perform a 3-minute step test. After your warm-up, step up and down in a four-count sequence as follows: right foot up, left up, right down, left down. Each time you move a foot up or down, it counts as one step.
Count "up, up, down, down" for one set, with 20 sets to the minute. It is very important that you don't speed up the pace--keep it regular. After 2 minutes, you'll need to monitor your heart rate for the last minute. The SubMax Step Test now can be used to predict your Max HR. Add to your last minute's heart rate average one of the following numbers:
1. Poor Shape: +55 bpm
2. Average Shape: +65 bpm
3. Excellent Shape: +75 bpm
Your result should be pretty close to your Max HR. (last-minute heart rate average might be something like 120 bpm, to which I'd add 75 bpm, bringing the total to 195 bpm.)
And how does one determine what to enter for for the shape their in, "Poor", "Average", or "Excellent"?0 -
I guess I should have thrown the solution in there to obtain the better accuracy. Though you still may want to subtract 12%.
It's the default calculations based on avg's that cause the biggest inaccuracy.
If you can find out your own figures for max HR, and if your monitor lets you do it, VO2 max, you can greatly improve the accuracy.
For VO2 max estimate:
http://www.brianmac.co.uk/queens.htm
Here is a submaximal test to estimate your max HR, if you feel like doing the true killer test (and serious, be fit already to do that one), you can find it at the above site.
. The SubMax Step Test. Use an 8" step (almost any step in your home or in a club will do) and perform a 3-minute step test. After your warm-up, step up and down in a four-count sequence as follows: right foot up, left up, right down, left down. Each time you move a foot up or down, it counts as one step.
Count "up, up, down, down" for one set, with 20 sets to the minute. It is very important that you don't speed up the pace--keep it regular. After 2 minutes, you'll need to monitor your heart rate for the last minute. The SubMax Step Test now can be used to predict your Max HR. Add to your last minute's heart rate average one of the following numbers:
1. Poor Shape: +55 bpm
2. Average Shape: +65 bpm
3. Excellent Shape: +75 bpm
Your result should be pretty close to your Max HR. (last-minute heart rate average might be something like 120 bpm, to which I'd add 75 bpm, bringing the total to 195 bpm.)
And how does one determine what to enter for for the shape their in, "Poor", "Average", or "Excellent"?
If just starting exercise program few weeks, poor, from there to can't do over 45 min with stopping for breather, average, can go 45 min or better with stopping at all, excellent.0 -
And how does one determine what to enter for for the shape their in, "Poor", "Average", or "Excellent"?
If just starting exercise program few weeks, poor, from there to can't do over 45 min with stopping for breather, average, can go 45 min or better with stopping at all, excellent.
Thank you!0 -
I guess I should have thrown the solution in there to obtain the better accuracy. Though you still may want to subtract 12%.
It's the default calculations based on avg's that cause the biggest inaccuracy.
If you can find out your own figures for max HR, and if your monitor lets you do it, VO2 max, you can greatly improve the accuracy.
For VO2 max estimate:
http://www.brianmac.co.uk/queens.htm
Here is a submaximal test to estimate your max HR, if you feel like doing the true killer test (and serious, be fit already to do that one), you can find it at the above site.
. The SubMax Step Test. Use an 8" step (almost any step in your home or in a club will do) and perform a 3-minute step test. After your warm-up, step up and down in a four-count sequence as follows: right foot up, left up, right down, left down. Each time you move a foot up or down, it counts as one step.
Count "up, up, down, down" for one set, with 20 sets to the minute. It is very important that you don't speed up the pace--keep it regular. After 2 minutes, you'll need to monitor your heart rate for the last minute. The SubMax Step Test now can be used to predict your Max HR. Add to your last minute's heart rate average one of the following numbers:
1. Poor Shape: +55 bpm
2. Average Shape: +65 bpm
3. Excellent Shape: +75 bpm
Your result should be pretty close to your Max HR. (last-minute heart rate average might be something like 120 bpm, to which I'd add 75 bpm, bringing the total to 195 bpm.)
And how does one determine what to enter for for the shape their in, "Poor", "Average", or "Excellent"?
If just starting exercise program few weeks, poor, from there to can't do over 45 min with stopping for breather, average, can go 45 min or better with stopping at all, excellent.
Another question...shouldn't age, weight, and current height be considered into this, as well?0 -
Another question...shouldn't age, weight, and current height be considered into this, as well?
It is if you think about it.
Who is going to have their HR rocket up higher, heavy or light person?
Old or young person?
Height? No.
So it really is included in the fact your HR will either be high or low based on those things. And as has been correctly found, age doesn't automatically cause HRmax to lower, if you stayed in cardio shape as you got older. If you got in shape while older, ya, it lowered, and you won't get any improvement from it.
So if you are old and HR didn't go up that and you are in Excellent shape, higher HR.
The only reason the HRM's get that extra data is to calculate BMI (height and weight) and then decide if that is good or bad of several levels (gender and age) - and from that they estimate a VO2max figure.
Now they use age to calculate a HRmax figure (220-age), the lactate threshold level is assumed to be 80-85% of that. That is the upper level of calorie burn for aerobic. The lower end is about 90 from studies for everyone.
Now with a HR range from 90 to LT, and a VO2max figure, they can calculate your estimated calorie burn per HR.0 -
My head hurts!
This ^^
... too... many...words.... and ...numbers..
*falls over*
aaah same here and I don't even have a HRM yet.... seems so complicated : /
I want a HRM but I am more confused than ever over what one to get...0 -
aaah same here and I don't even have a HRM yet.... seems so complicated : /
I want a HRM but I am more confused than ever over what one to get...
Polar FT40 or 60, or RS300X - all have the VO2max value, and self test. The only way to have a modicum of accuracy.
Or Garmin Forerunners 910XT & 310XT & 610 & 410 & 210 & 110, 405CX, Edges 800 & 5000 -
Hmmm, interesting. I have the FT7 and it tells me I burn less than most calorie calculators and the machine. I prefer the ft7 calcuations0
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This ^^
... too... many...words.... and ...numbers..
*falls over*
aaah same here and I don't even have a HRM yet.... seems so complicated : /
I want a HRM but I am more confused than ever over what one to get...
[/quote]
I KNOW! Me too! :-/0 -
I always leave 100 or so calories or approx 10% off when I mark down my HRM cals.0
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I have a Polar FT4 which appears to me to be accurate. Usually it's the gym equipment that is up to 100 calories off, above that of my HRM. If I alternate on a walk between a flat path and hills, I see a difference in the calories burned.0
This discussion has been closed.
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