WARNING! POLAR HEART RATE MONITORS DEFECTIVE!
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Todays data set
Total run 55 min on treadmill
warm up
Avr HR 143 171 kcal 14:30 Weight set 85 --> 11.8 kcal/min
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Avr HR 163 150 kcal 10:14 Weight set 95 --> 14.6 kcal/min
Avr HR 166 129 kcal 9:12 Weight set 115--> 14.0 kcal/min** yep something fishy from 95kg to 115kg**
Avr HR 162 165 kcal 13.38 weight set 145 --> 12.1 kcal/min** something very fishy **
You could probably graph kcal/min vs Weight for different HRs curves and see how the function shows up.
Thank you for posting your results!
yes, this is inverse of what you would expect.
To confirm those weights entered are in kilos, not pounds?
Yes, kilos.
You've piqued my data fixation. I'll likely do a whole bunch of evaluations in my runs and I'll let you know. Today's run was more of a focus on my girls who where riding next to me. Even though I used the three tools (polar/Garmin/iPhone) I didn't bother with variations or even differential readings. I'll keep you posted.
The energy is measured by carrying a weight across a distance not time. It's the kcal/mile that matters.
the more weight you are carrying, certainly more calories or energy will be expended.
The more energy expended, the higher the heart rate. If you put weight on my back I will burn more and it will be reflected by a higher heart rate. You can't increase the weight at the same heart rate and wonder why cal/min is going down.
We aren't carrying more weight we are fiddling with the watch settings which should give a higher burn at a higher weight setting all other parameters being constant.
Why should it give you a higher burn at a higher weight ? This assumption is wrong.0 -
Good for you, EvgeniZyntx. I love data crunching for the same reasons too. Just part of my personality.0
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I'm not sure if you got the correct answer in all these pages, because probably only half-dozen that I've seen on MFP has the answers.
That cheaper Polar model has NO stat for VO2max, which is then required to estimate.
Because calories burned is totally related to that stat and HRmax.
So how do you estimate VO2max with no stat?
BMI - Polar assumes that if you weigh more and your BMI is worse, you are less in shape, therefore an elevated HR means you burned say 500 calories to accomplish a given workload for your weight.
But, if you are actually in shape at that weight, your lower HR to accomplish the same work still means you burned 500 calories, but Polar sees the lower HR and assumes being unfit, you didn't work as hard, so they show you only burned 400 calories.
Same thing works if you kept the HR exactly the same, but your weight went down.
Heavy weight, HR of 150, burned 500.
Lower weight, HR of 150, burned 600.
It's not a defect - except for people expecting a HRM with missing stats to give a great estimate of calories burned what that isn't even the tool's primary purpose.
This is why those cheaper models really under-report calories burned as you get fit but don't lose weight as fast.
If you did a treadmill walk at 4 mph at given weight and 1 week into working out, your HR may have been 150.
You kept doing it, you got fit.
You do the same walk at the same weight. Did the workload change? The calories burned is the same. But now your HR only needs to be 120 to do the same amount of work.
Calories burned is the same.
But for the Polar with no VO2max stat, the first walk at 150 gets bigger calorie burn reported than the second walk at 120 - even though the calories burned would be exactly the same!
Which is right? Probably inbetween. That BMI method assumes an average fitness level for given BMI.
Try experimenting - change the height now by about 20 inches and see what happens. Make it taller for given weight so BMI is in healthy zone.0 -
Hardly defective. MY average rate on my run is 158, doing zumba its 121 , doing my steps it's 130. Sorry but I'm guessing it's IS you.
But then I have a FT60 & an FT4
The algorithm for his device does seem wrong for someone weighing 300ish pounds. I'm more concerned about everyone being so hung up on all these calculated guesses and using them like they are real. With everyone's goal being to change their lifestyle to get healthy and many to lose weight, wouldn't it be better to find something fun to do? How long can it keep your interest to keep track of all these wrong numbers. How long before your bored with all this data?
It is demotivating when the data is off by 30-50%.
The data is motivating because net calories lost = weight loss.
I agree its good to find something fun to do is the long term key to staying active and fit.0 -
I'd like to see other people report their data result at different weight. The lower weight seem fine. But the higher the weight it seems the less accurate the results.Y'know. I had a mate who was a mad cyclist. He was a really big boy though, but after checking his stats and heart rate, he turned out to be amazingly fit even though his weight never shifted. Mym mum's the same. Built like a bullock and keeps a low heart rate despite her slightly generous size. You might be working at a lower heart rate than you expect. I have trouble getting mine up above the 130s/140s even when powering up really tough hills. Try different intensities and see if you can get variations there. Otherwise just send the watch back for a refund.0 -
I'm not sure if you got the correct answer in all these pages, because probably only half-dozen that I've seen on MFP has the answers.
That cheaper Polar model has NO stat for VO2max, which is then required to estimate.
Because calories burned is totally related to that stat and HRmax.
So how do you estimate VO2max with no stat?
BMI - Polar assumes that if you weigh more and your BMI is worse, you are less in shape, therefore an elevated HR means you burned say 500 calories to accomplish a given workload for your weight.
But, if you are actually in shape at that weight, your lower HR to accomplish the same work still means you burned 500 calories, but Polar sees the lower HR and assumes being unfit, you didn't work as hard, so they show you only burned 400 calories.
Same thing works if you kept the HR exactly the same, but your weight went down.
Heavy weight, HR of 150, burned 500.
Lower weight, HR of 150, burned 600.
It's not a defect - except for people expecting a HRM with missing stats to give a great estimate of calories burned what that isn't even the tool's primary purpose.
This is why those cheaper models really under-report calories burned as you get fit but don't lose weight as fast.
If you did a treadmill walk at 4 mph at given weight and 1 week into working out, your HR may have been 150.
You kept doing it, you got fit.
You do the same walk at the same weight. Did the workload change? The calories burned is the same. But now your HR only needs to be 120 to do the same amount of work.
Calories burned is the same.
But for the Polar with no VO2max stat, the first walk at 150 gets bigger calorie burn reported than the second walk at 120 - even though the calories burned would be exactly the same!
Which is right? Probably inbetween. That BMI method assumes an average fitness level for given BMI.
Try experimenting - change the height now by about 20 inches and see what happens. Make it taller for given weight so BMI is in healthy zone.
I think most people trying to lose weight the calories burned is the most important stat for them.
Just looking at the raw data though you must see something is amiss. Without changing any other variables when you increase the weight the calories burned goes down. It simply does not make sense.0 -
Y'know. I had a mate who was a mad cyclist. He was a really big boy though, but after checking his stats and heart rate, he turned out to be amazingly fit even though his weight never shifted. Mym mum's the same. Built like a bullock and keeps a low heart rate despite her slightly generous size. You might be working at a lower heart rate than you expect. I have trouble getting mine up above the 130s/140s even when powering up really tough hills. Try different intensities and see if you can get variations there. Otherwise just send the watch back for a refund.
Done the finger to neck thing to check against reality. heart rate of Polar is accurate.0 -
My suggestion in the end would be to go and get a full fitness test done. Then you know whether it's you or your Polar.0
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I wonder if at the higher weight the "connection" between the HRM and the HR was not as good. My weight has not changed for the last few years but when I am cold my HRM is all wonky. The "connection" to my body is not as good. Could it have been the extra fat getting in the way of a proper HR reading. You know those handheld body fat indicators they use at the gym to tell you how out of shape you are? I was told those don't get as good of a reading if one is dehydrated, has already worked out, it is late in the day etc...if these devices are that sensitive then it is possible that at a certain body fat percentage the HR readings just are not as good?0
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I'm not sure if you got the correct answer in all these pages, because probably only half-dozen that I've seen on MFP has the answers.
That cheaper Polar model has NO stat for VO2max, which is then required to estimate.
Because calories burned is totally related to that stat and HRmax.
So how do you estimate VO2max with no stat?
BMI - Polar assumes that if you weigh more and your BMI is worse, you are less in shape, therefore an elevated HR means you burned say 500 calories to accomplish a given workload for your weight.
But, if you are actually in shape at that weight, your lower HR to accomplish the same work still means you burned 500 calories, but Polar sees the lower HR and assumes being unfit, you didn't work as hard, so they show you only burned 400 calories.
Same thing works if you kept the HR exactly the same, but your weight went down.
Heavy weight, HR of 150, burned 500.
Lower weight, HR of 150, burned 600.
It's not a defect - except for people expecting a HRM with missing stats to give a great estimate of calories burned what that isn't even the tool's primary purpose.
This is why those cheaper models really under-report calories burned as you get fit but don't lose weight as fast.
If you did a treadmill walk at 4 mph at given weight and 1 week into working out, your HR may have been 150.
You kept doing it, you got fit.
You do the same walk at the same weight. Did the workload change? The calories burned is the same. But now your HR only needs to be 120 to do the same amount of work.
Calories burned is the same.
But for the Polar with no VO2max stat, the first walk at 150 gets bigger calorie burn reported than the second walk at 120 - even though the calories burned would be exactly the same!
Which is right? Probably inbetween. That BMI method assumes an average fitness level for given BMI.
Try experimenting - change the height now by about 20 inches and see what happens. Make it taller for given weight so BMI is in healthy zone.
I think most people trying to lose weight the calories burned is the most important stat for them.
Just looking at the raw data though you must see something is amiss. Without changing any other variables when you increase the weight the calories burned goes down. It simply does not make sense.
He just gave you a very detailed, educated answer as to why you are wrong about this (thank you heybales !).
Increasing your weight without changing any other variables *should* give you a lesser calorie count. Higher weight at the same HR means slower speed, less distance, less work.0 -
I do enjoy looking at numbers and analyzing everything. At some point though, I think you have to assume that losing weight is a lot more estimating than we wish it was. There are many articles floating around the internet over nutrition labels as well as heart rate monitors. I've read that even groceries can be within 7 percent off its listed calories and restaurant meals within 20 percent. So even with a scale, you're not always eating exactly the number of calories you think.
I'm 23 and my heart rate hovers near 180 during runs. If I run for 30 minutes, I make sure to eat a couple hundred extra calories that day. I don't wear my garmin hrm during every run because I don't think it's capable of telling me anything super significant. I can tell when I'm pushing myself.
From your posts it seems that you are a very numbers oriented, exact kind of person. I hope you can get some answers from Polar because there does seem to be a discrepancy at heavier weights.0 -
I think most people trying to lose weight the calories burned is the most important stat for them.
Just looking at the raw data though you must see something is amiss. Without changing any other variables when you increase the weight the calories burned goes down. It simply does not make sense.
Well, then there is the misunderstanding and problem.
You have a tool that has been shown to loosely tie together HR and calories burned, by formula based on other stats actually.
But it is a loose affiliation even with the same person.
But you are using a tool missing some pieces, so it's not as good.
Could Polar have just included the fields for stats in the cheaper watches - sure. The formula is already there.
You can decide how much you like or dislike Polar's business practices.
I don't like them, to have such minor contrived differences between models seems stupid to me.
Like HR zone alarms. Put an upper alarm on the FT7, but not a lower one.
They had models in the past where cheaper had upper but no audio option, so you had to look at watch to see icon. Stupid. Watch already beeped for things.
It takes more effort to go back in and disable some functions for the cheaper versions. But from signs on MFP and elsewhere, their marketing methods work just fine.
And they are catering to the crowd that wants calorie burn info.
Later when they discover they want more than no or few features, they'll spend big bucks on more expensive model to actually train with.0 -
Thank you all for your input and observations.
After all the input I've heard so far the conclusion is still the same
The higher the weight you enter on the Polar FT7 the more likely that it is not accurate.
For example, at 300 pounds or above it appears to be between 30-50%. Surely it must vary 0-20% from reality depending on a lot of factors from individual to individual but the numbers I'm getting a just way off. This is also true for a lot of other people posting here, especially at higher weights. Something is surely amiss.0 -
Thank you all for your input and observations.
After all the input I've heard so far the conclusion is still the same
The higher the weight you enter on the Polar FT7 the more likely that it is not accurate.
For example, at 300 pounds or above it appears to be between 30-50%. Surely it must vary 0-20% from reality depending on a lot of factors from individual to individual but the numbers I'm getting a just way off. This is also true for a lot of other people posting here, especially at higher weights. Something is surely amiss.
I'll agree that at some point, the BMI method of assuming VO2max probably is just a matter of "greater than this, then that" type table.
A sliding scale would be best, but even then, probably only up to a certain level, then everything past that the same number is used for.
Good to know though, I've been trying to figure out how to backward engineer how they do the BMI estimate method, as many studies do use it.
But also, past a certain weight you don't continue a linear progressive increase in calories burned.
Notice these very accurate walking calc's up to 4mph. More accurate than HRM's in fact by a big margin. Not linear if graphed out.
http://www.exrx.net/Calculators/WalkRunMETs.html0 -
I'm not sure if you got the correct answer in all these pages, because probably only half-dozen that I've seen on MFP has the answers.
That cheaper Polar model has NO stat for VO2max, which is then required to estimate.
Because calories burned is totally related to that stat and HRmax.
So how do you estimate VO2max with no stat?
BMI - Polar assumes that if you weigh more and your BMI is worse, you are less in shape, therefore an elevated HR means you burned say 500 calories to accomplish a given workload for your weight.
But, if you are actually in shape at that weight, your lower HR to accomplish the same work still means you burned 500 calories, but Polar sees the lower HR and assumes being unfit, you didn't work as hard, so they show you only burned 400 calories.
Same thing works if you kept the HR exactly the same, but your weight went down.
Heavy weight, HR of 150, burned 500.
Lower weight, HR of 150, burned 600.
It's not a defect - except for people expecting a HRM with missing stats to give a great estimate of calories burned what that isn't even the tool's primary purpose.
This is why those cheaper models really under-report calories burned as you get fit but don't lose weight as fast.
If you did a treadmill walk at 4 mph at given weight and 1 week into working out, your HR may have been 150.
You kept doing it, you got fit.
You do the same walk at the same weight. Did the workload change? The calories burned is the same. But now your HR only needs to be 120 to do the same amount of work.
Calories burned is the same.
But for the Polar with no VO2max stat, the first walk at 150 gets bigger calorie burn reported than the second walk at 120 - even though the calories burned would be exactly the same!
Which is right? Probably inbetween. That BMI method assumes an average fitness level for given BMI.
Try experimenting - change the height now by about 20 inches and see what happens. Make it taller for given weight so BMI is in healthy zone.
The input that you give here is very good in terms of the issue at hand but I'm going to suggest an issue with your example but not your analysis. Let's talk about the treadmill example, if you don't mind.
In short, while the mechanical work is the same and the load did not change the muscular efficiency does change (fiber recruitment, neurological changes, mitochondrial whatnot, and even muscle fiber type over long term) and muscular work has a large thermal component that is not the same in the two cases. From my human physiology courses (in the last century) mechanical work only corresponds to about a quarter of metabolic energy use; it's the other components of energy use that are also changing. Therefore the metabolic calories consumed are not the same in this example for the fit and not fit. While VO2max does increase with training and probably remains the best measure there are significant efficiency gains that do not translate to VO2max gains.
Examples of this are all the elite cycling studies where VO2max goes slightly down with increased work/power capacity.
And of course, that woud be another example of issues with HRM used to calculate "burn".
And there is the whole confusion between relative and absolute V02max. As you likely know, two individuals with the same absolute V02max will have different fitness levels depending on their weight.
But I think you hit the head on the head - the use of a BMI in these HRM makes assumptions about fitness levels that can be significant error inducing. Probably for the general population, even at higher weight the error level is not that high as the discussion here has led us to believe. I.e. if I was keeping a specific HR and weighed 3x I'd certainly go slower, cover less distance and provide less mechanical work.
Anyway, my conclusion is that I should get my old Polar repaired or get another one :huh: - and that I do tend to focus on the right fitness parameters with regards to a HRM - resting HR (used as an estimator of VO2max), max HR for a given effort, and time to return to a base HR after effort. As an old cyclist, those were our canonic training guides and I sort of only glance at them now.
Thanks for the discussion points.0 -
Was considering purchasing the FT4. This one should be accurate I hope?0
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Was considering purchasing the FT4. This one should be accurate I hope?
More than a cheaper one. Is up to 40% still accurate enough for you?
http://www.myfitnesspal.com/topics/show/459580-polar-hrm-calorie-burn-estimate-accuracy-study
But as expressed above, all kinds of reasons for inaccuracies even without the fact the cheaper Polar like the FT4 is missing a very important stat they will be assuming, based on your BMI.0 -
In short, while the mechanical work is the same and the load did not change the muscular efficiency does change (fiber recruitment, neurological changes, mitochondrial whatnot, and even muscle fiber type over long term) and muscular work has a large thermal component that is not the same in the two cases. From my human physiology courses (in the last century) mechanical work only corresponds to about a quarter of metabolic energy use; it's the other components of energy use that are also changing. Therefore the metabolic calories consumed are not the same in this example for the fit and not fit. While VO2max does increase with training and probably remains the best measure there are significant efficiency gains that do not translate to VO2max gains.
Examples of this are all the elite cycling studies where VO2max goes slightly down with increased work/power capacity.
And of course, that woud be another example of issues with HRM used to calculate "burn".
And there is the whole confusion between relative and absolute V02max. As you likely know, two individuals with the same absolute V02max will have different fitness levels depending on their weight.
Ya, I love that running pace estimates that take your VO2max and calculate a pace you should be able to do. Without weight being asked for. Ya, I'll run my knees and feet into the ground maintaining that 7 min pace for oh, 3-4 miles right now.
I'm thinking running might see better efficiency gains.
I used the walking example because of the tight bell curve on energy spent walking different speeds. I don't think you'd see significant efficiency gains if you'd done any walking. Just not used to doing it for a long time.
But really, some of what you describe as changing and improving efficiency, is exactly why the VO2max improves, and HR lowers, to provide the same oxygen to a system that is much more efficient at using it now. So the energy use is a whole lot tighter I'd believe unless you are comparing different people, or really improving your running, biking, swimming efficiency.
Like the study of cyclist and optimum cadence. Rider naturally selected wasn't the most efficient, but it gave better results over all. Pro-cyclist, so they knew what felt like their own best efficiency.
Oh, the study showing how tight the calorie burns are for walking.
http://www.ncbi.nlm.nih.gov/pubmed/15570150
While it was mainly talking about the calculation predictions, the measured expenditure is within 5 calories when weight adjusted. We seem to walk at certain speeds with pretty equal efficiency since we've been doing it for so long. Once we can pull ourselves off the bike anyway.0 -
I've had no problems with my FT4. It gives EXACTLY the same reading as the cardio equipment at my gym after I punch in my details It gave me about a 5000 odd calorie reading for my last marathon and my g'friend who is same age, similar build to me clocked similar results on her FT4 over a same distance. Check your battery, check that you have the strap on properly and the sensors are wet. Remember to adjust your weight in the settings as it changes too. Hope you find a better result.
This. I've only had mine for about a week but so far it's been right on gym equipment and other calorie calculators.0 -
In short, while the mechanical work is the same and the load did not change the muscular efficiency does change (fiber recruitment, neurological changes, mitochondrial whatnot, and even muscle fiber type over long term) and muscular work has a large thermal component that is not the same in the two cases. From my human physiology courses (in the last century) mechanical work only corresponds to about a quarter of metabolic energy use; it's the other components of energy use that are also changing. Therefore the metabolic calories consumed are not the same in this example for the fit and not fit. While VO2max does increase with training and probably remains the best measure there are significant efficiency gains that do not translate to VO2max gains.
Examples of this are all the elite cycling studies where VO2max goes slightly down with increased work/power capacity.
And of course, that woud be another example of issues with HRM used to calculate "burn".
And there is the whole confusion between relative and absolute V02max. As you likely know, two individuals with the same absolute V02max will have different fitness levels depending on their weight.
Ya, I love that running pace estimates that take your VO2max and calculate a pace you should be able to do. Without weight being asked for. Ya, I'll run my knees and feet into the ground maintaining that 7 min pace for oh, 3-4 miles right now.
I'm thinking running might see better efficiency gains.
I used the walking example because of the tight bell curve on energy spent walking different speeds. I don't think you'd see significant efficiency gains if you'd done any walking. Just not used to doing it for a long time.
But really, some of what you describe as changing and improving efficiency, is exactly why the VO2max improves, and HR lowers, to provide the same oxygen to a system that is much more efficient at using it now. So the energy use is a whole lot tighter I'd believe unless you are comparing different people, or really improving your running, biking, swimming efficiency.
Like the study of cyclist and optimum cadence. Rider naturally selected wasn't the most efficient, but it gave better results over all. Pro-cyclist, so they knew what felt like their own best efficiency.
Oh, the study showing how tight the calorie burns are for walking.
http://www.ncbi.nlm.nih.gov/pubmed/15570150
While it was mainly talking about the calculation predictions, the measured expenditure is within 5 calories when weight adjusted. We seem to walk at certain speeds with pretty equal efficiency since we've been doing it for so long. Once we can pull ourselves off the bike anyway.
Ok, for walking, I'd completely agree, and I guess I missed that and was focusing on the VO2max.
Btw, the study I saw discussing decrease in VO2 while increase in output was not about optimum cadence but suggested muscular modifications over time (fiber changes), let me see if I can find it.
Here, found the article and the blog: http://trainingscience.net/?page_id=618
http://www.ncbi.nlm.nih.gov/pubmed/19346977
Of course, that might not be normal physiological change.0
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