WARNING! POLAR HEART RATE MONITORS DEFECTIVE!
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This is why I gave up on heart rate monitors in the first few months after I started losing. They just aren't worth the money.
Also... and I'm not sure where I read this, but...
I think the formula used to calculate the calorie burn on the HRM cannot be applied to those who are morbidly obese. I think there are some additional factors that come into play and the HRM's just aren't programmed to account for it.
Again, I could be wrong on that.0 -
109 seems a very low heart rate. I am pretty fit (cardio 5 days a week and heavy lifting 5 days as well)
MY heart rate when I'm running is in the 160's-170's. 109 for BPM seems like you're not working very hard at all.
not looking for your comments.
looking for data. please share.
How about quit being rude and repeating the same thing to just about every other person. I was going to chime in and add my input, but why should I give you that respect when you do not give respect to all have contributed in this thread.
yeah, that was kind of rude. I apologize to the original poster and everyone else here. Just a bit frustrated with not much data.
But really, I'd like to know what is going on. Again, this applies to really a relatively small amount of people. Not many people are in the very high range so not many can really reply with significant data since most replies will be at lower weights and their data is not in question. By high weight I'm saying 300+, but it could be lower. not sure.
Ok, cool, I'm glad that you can admit it and apologized. Yeah, I can understand being frustrated because something is not right with the HRM! Good luck getting data and answers.0 -
so, you are saying all HRM calorie burn estimates should be ignored?
Yes. That is why they are called "HEART RATE" monitors, not "CALORIE" monitors.
Just as you don't trust your odometer in your car to tell you how fast you are driving or the temperature reading on your GPS to pick out your clothing for the day.
Thank you. Saying what we tried to say on page one or two, and making me giggle while doing it :flowerforyou:0 -
Been using my Polar FT60 for a few years now and rely on my calorie burn number to eat back 85% of those exercise calories leaving 15% for error and have managed to lose a few pounds so in my own personal opinion, I think I will continue on with the status quo, whats the old saying "If it isn't broke, don't fix it." For the record my avg. burns are 14 calories a minute and that is with a heart rate running between 145-160 with a few peaks towards the end pushing 170.... This has not changed a whole heck of a lot from the time I was over 400 (couldn't walk back at 560 lbs. so I spent over a year walking in a therapy pool before I could get fitted with braces and walk on dry ground and is when I started using a heart rate monitor.) til now maybe 4 cal. burn a minute difference roughly between now and back then which amounts to around 200 calories over a 65 minute period...... Best of Luck...0
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so, you are saying all HRM calorie burn estimates should be ignored?
Yes. That is why they are called "HEART RATE" monitors, not "CALORIE" monitors.
Just as you don't trust your odometer in your car to tell you how fast you are driving or the temperature reading on your GPS to pick out your clothing for the day.
If the temperature on my GPS says 20º F, then I think I'm dressing warm and wearing a coat. 0 -
My test on my watch:
3 min
3 kcal
avr 55
weight 89 kg
3 min
6 kcal
avr 55
weight 199 kg
This HRM (polar FT7) does not go higher than 199 kg. Real world test above shows no issue.
your heart rate is not high enough to be reliable. should be at least 95.
thanks for trying though.
Err, no, it demonstrates that the equation is, at least on my watch not showing the same issue as yours with respect to weight. Higher weight = higher burn (all other variables constant). BTW using avr HR in your calc assumes that burn is linear with increase in HR, it isn't.
Eta: this thread is all over the place - are you trying to test the HR equation dependency at higher weight or just putting in a lot of doubt on HRM. I'm nt even sur that the data set includes enough people for the equations at weights higher than 300 lbs.
And I don't buy the dea that weight is coded on a bit level that would invalidate beyond 256 lbs, I'm using kg and my watch is limited to 199 kgs. You might try to set your watch to kg and see if you get the same results.0 -
My test on my watch:
3 min
3 kcal
avr 55
weight 89 kg
3 min
6 kcal
avr 55
weight 199 kg
This HRM (polar FT7) does not go higher than 199 kg. Real world test above shows no issue.
your heart rate is not high enough to be reliable. should be at least 95.
thanks for trying though.
Err, no, it demonstrates that the equation is, at least on my watch not showing the same issue as yours with respect to weight. Higher weight = higher burn (all other variables constant). BTW using avr HR in your calc assumes that burn is linear with increase in HR, it isn't.
Eta: this thread is all over the place - are you trying to test the HR equation dependency at higher weight or just putting in a lot of doubt on HRM. I'm nt even sur that the data set includes enough people for the equations at weights higher than 300 lbs.
And I don't buy the dea that weight is coded on a bit level that would invalidate beyond 256 lbs, I'm using kg and my watch is limited to 199 kgs. You might try to set your watch to kg and see if you get the same results.
It is commonly accepted that HRM don't work well at lower heart rates.
I really would like to see what kind of numbers people at high weights have to see if they have gotten similar suspect readings as I have.0 -
so, you are saying all HRM calorie burn estimates should be ignored?
Yes. That is why they are called "HEART RATE" monitors, not "CALORIE" monitors.
Just as you don't trust your odometer in your car to tell you how fast you are driving or the temperature reading on your GPS to pick out your clothing for the day.
You don't trust the odometer on your car? I think you actually prove my point. It should be quite close, within 5%. I think HRM should be within say 10-20% of actual. 20% is not very good either, but you know without doing all the fancy tests you don't really know. I believe my reading are off by 30-50%, which is beyond acceptable range of variance IMO.0 -
You need to seriously up your workrate to get your HR into an actual zone. I don't care if you're 16, 26, 36 or 46, your using your HRM outside the "normal" range at which it's algorithms will be closer to (but not) accurate.
BTW, HRM's are useful for telling you if you're slacking off in a steady state cardio type workout, or if you're getting in and out of zones in an interval workout. For accuracy in calories burnt? Not so much....
I am in a "zone", the "Burn Fat" zone. See below. Age 46. My max heart rate is 176. x by .6 and you get 105.6. So not sure what you are talking about?
Ideal For Benefit Desired Intensity Level (% Maximum heart rate)
Light Exercise Maintain Healthy Heart/Get Fit 50% - 60%
Weight Management Lose Weight/ Burn Fat 60% - 70%
Aerobic Base Building Increase Stamina Aerobic Endurance 70% - 80%
Optimal Conditioning Maintain Excellent Fitness Condition 80% - 90%
Elite Athlete Maintain Superb Athletic Condition 90% - 100%0 -
My test on my watch:
3 min
3 kcal
avr 55
weight 89 kg
3 min
6 kcal
avr 55
weight 199 kg
This HRM (polar FT7) does not go higher than 199 kg. Real world test above shows no issue.
your heart rate is not high enough to be reliable. should be at least 95.
thanks for trying though.
Err, no, it demonstrates that the equation is, at least on my watch not showing the same issue as yours with respect to weight. Higher weight = higher burn (all other variables constant). BTW using avr HR in your calc assumes that burn is linear with increase in HR, it isn't.
Eta: this thread is all over the place - are you trying to test the HR equation dependency at higher weight or just putting in a lot of doubt on HRM. I'm nt even sur that the data set includes enough people for the equations at weights higher than 300 lbs.
And I don't buy the dea that weight is coded on a bit level that would invalidate beyond 256 lbs, I'm using kg and my watch is limited to 199 kgs. You might try to set your watch to kg and see if you get the same results.
It is commonly accepted that HRM don't work well at lower heart rates.
I really would like to see what kind of numbers people at high weights have to see if they have gotten similar suspect readings as I have.
HR monitors work at lower HRs, what they do not do is calculate the calorie burn accurately as the calorie equation has a higher variance at low HRs. But the HR capture is accurate. Therefore if you test at two weights - it will tell you if the function to cals is higher/lower based on that single parameter even at low HR. It is what I tested for you. It has nothing to do with accuracy but difference of results at two weight settings.
I'll do a test at a higher HR later today, just to provide you with the info. I expect I will get a higher burn reading at a higher weight setting. I'll even do it with two HRMs (yes, I'm a HRM junky).0 -
My test - elliptical
Polar Ft7
Avr 102
Max 109
Time 7:01
Cal 41
Weight setting: 85 kg
Avr 100
Max 116
Time 7:01
Cal 36
Weight setting: 158 kg
So is the 0.7 cal/min difference due to the 2 heartbeat average difference or an error in the formula at these higher weights? I guess you'll need to do a set of 20 or more measures at each weight and at different HRs to test. I'm going to stop here.
Again, calories burned in not a linear function of HR - there are some second order elements at rates near HRmax so calculations based on averages are slightly off.
Anyway, trying to pin a small difference of 5 to 10% here has little value as our food calculations already vary at least 15-20% from "nutritional" values.
What makes you think yours is off by up to 50%?
Btw, my garmin gave 0 cals for both, I had forgotten that this unit calculates burn on gps data and sport mode.0 -
My test - elliptical
Polar Ft7
Avr 102
Max 109
Time 7:01
Cal 41
Weight setting: 85 kg
Avr 100
Max 116
Time 7:01
Cal 36
Weight setting: 158 kg
So is the 0.7 cal/min difference due to the 2 heartbeat average difference or an error in the formula at these higher weights? I guess you'll need to do a set of 20 or more measures at each weight and at different HRs to test. I'm going to stop here.
Again, calories burned in not a linear function of HR - there are some second order elements at rates near HRmax so calculations based on averages are slightly off.
Anyway, trying to pin a small difference of 5 to 10% here has little value as our food calculations already vary at least 15-20% from "nutritional" values.
What makes you think yours is off by up to 50%?
Btw, my garmin gave 0 cals for both, I had forgotten that this unit calculates burn on gps data and sport mode.
so your result look about even at both weights. Someone at a higher weight definitely burns more calories than someone at a lesser weight so if you ask me though not as drastic as my results are inverse to what you would expect to your results do support my theory that there is something wrong.
I think the idea is that it takes a lot more energy to move a larger mass at that heart rate than a smaller mass.
And I do understand that it is not linear. In fact, there are quite a number of factors involved. But weight is a big one when there is a large gap.
Still no word from Polar. Very interested to see what they have to say. Love it if they got involved in the post here.0 -
After having a day to digest responses I have a few thoughts. First, I wan't to thank all the people who responded. Next, I did not get the data I was looking for. Some people gave some decent responses, a few verified that they had similar wacky results, others said they had no such problem (but all were people at lower weights where I am not claiming there to be any problems). The few that were at high weights did verify that they had similar problems, but really did not give much data either.
I still can't get by the actual facts. Without changing any other variable other than weight DOWN by 138 pounds my calories burned INCREASED from 6.5 to 8.1 per minute. This is simply ridiculous. Heavier people burn more calories. That's the fact. Many of you pointed out some potential flaws in my assertions, but none of them were valid IMHO.
Frankly none of anyone's objections hold water with me since I only changed one variable making it a valid experiment. I just can't ignore the data. THERE IS SOMETHING SERIOUSLY WRONG WITH THE POLAR FT7 FOR PEOPLE WHO ARE AT HIGHER WEIGHTS.
Many of you said it's just an estimate, don't take the number seriously. Well, that does not work either since many people use those numbers above machines and online calculators to decide how much to eat and in their goal setting. It can also have a psychological effect when you think you did all this work and so low a calorie burn. If the Polar FT7 is off by 30-50% as I suspect it is that will hinder the ability of people to effectively manage their weight loss plan.
Polar has not gotten back to me either. When they do I will post what they said.0 -
ive own 3 polars in my life so far and ive used two to see if the calories were accurate (with same stats in both watches), one was burning 100 calories more than the other, In a way it does not bother me. Realistically no HRM is dead on.0
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ive own 3 polars in my life so far and ive used two to see if the calories were accurate (with same stats in both watches), one was burning 100 calories more than the other, In a way it does not bother me. Realistically no HRM is dead on.
not debating stats for people less than 300 pounds and your results are not surprising.0 -
I'll keep this in mind if I ever break 300 but for right now, my FT4 (yeah don't make fun of my dinosaur HRM) works just fine for me at my current weight 0
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You don't trust the odometer on your car? I think you actually prove my point. It should be quite close, within 5%. I think HRM should be within say 10-20% of actual. 20% is not very good either, but you know without doing all the fancy tests you don't really know. I believe my reading are off by 30-50%, which is beyond acceptable range of variance IMO.
Crap, I meant to say tachometer (which reports engine RPMs) and killed my own analogy.
Given that heart rate itself is highly variable (it goes up in the heat, down in the cold, up when physically tired, down when neurologically tired, up when nervous, up when scared, up when annoyed, up when dehydrated, up when you have been exercising more than about 30 minutes... and on and on and on), you really can't expect any monitor to give you an accurate calorie burn on heart rate alone (even if you include VO2max, body weight, and body fat stats).Many of you said it's just an estimate, don't take the number seriously. Well, that does not work either since many people use those numbers above machines and online calculators to decide how much to eat and in their goal setting. It can also have a psychological effect when you think you did all this work and so low a calorie burn. If the Polar FT7 is off by 30-50% as I suspect it is that will hinder the ability of people to effectively manage their weight loss plan.
The same could be said for every piece of fitness equipment in every gym and every website that provides calorie information.
It's not news, but I think I lot of people like the artificially high calorie burn numbers so they accept it. It's one likely explanation for why so many machines reading high, but none reading low.
Someone decided that HRMs and fitness machines should report calories, and suddenly they all did it, whether it was accurate or not.0 -
Peter
Did you retest several times? Did you try this with Kgs vs lbs?
While your HRM might not work, I'm not seeing evidence that this is a general issue with all FT7 especially since setting resting HR and MaxHR are parameters that can be set on mine and others but not in yours. Perhaps you have a faulty/counterfeit/old one?
I'm going for a long run this weekend, might do a more extensive test.0 -
Just for the heck of it I looked for a workout session where I averaged 109 on my FT7 and found one. When I looked at the calories per minute it was 7.5 currently i weigh 255 so seems to be roughly in line with your 190 and 320 weights. I'm assuming that the hrm is set with a particular sweet spot and as you depart from that sweet spot going in either direction the accuracy is going to suffer. What that sweet spot is I don't know.
I don't agree. compare these numbers. Does this look right to you? your age also is different than mine I guess so that could affect it, but weight is has much more "weight" in the algorithm overall. your burn is likely significantly higher than what your FT7 is saying.
check out this site and plug in your numbers here.
http://www.calories-calculator.net/Calories_Burned_By_Heart_Rate.html
8.1 calories/minute - 190 pounds.
7.5 calories/minute - 255 pounds (your numbers).
6.5 calories/minute - 326 pounds.
Okay, I did that website, and it said I would only burn about 3.59 calories per minute with a heart rate of 109 BPM. I then looked at the formula they are using:
(age*.074 + kg*.1263 + hrmBPM*.4472 -20.4022) * time / 4.184
Using this formula, entering the exact same stats, it gave me a calories burned per minute of 11.07 for my stats. I played around in Excel to see where the discrepency is coming in, and it appears that the calculator, for some reason, is SUBTRACTING the (kg*.1263) part instead of adding it. Maybe the HRM is doing something similar?
Conversely, using the calculations for male seems to be match up with the calculator and with the formula. I think there must be a glich somewhere because logic tells me that a person weighing 2x what another person does would burn more calories if their HR and ages and sexes were the same, no matter what the other factors.
ETA: Just found this same formula on a Livestrong article, however it does have that you subtract the weight and not add it. The men's formula adds the weight on the Livestrong article. I'm not understanding why a man's caloric burned would be positively effected by the weight but a woman's would be negatively effected? Granted, men generally have more LBM, but having more weight is still going to have a positive effect on caloric burn, right? Am I missing something here?0 -
Just for the heck of it I looked for a workout session where I averaged 109 on my FT7 and found one. When I looked at the calories per minute it was 7.5 currently i weigh 255 so seems to be roughly in line with your 190 and 320 weights. I'm assuming that the hrm is set with a particular sweet spot and as you depart from that sweet spot going in either direction the accuracy is going to suffer. What that sweet spot is I don't know.
I don't agree. compare these numbers. Does this look right to you? your age also is different than mine I guess so that could affect it, but weight is has much more "weight" in the algorithm overall. your burn is likely significantly higher than what your FT7 is saying.
check out this site and plug in your numbers here.
http://www.calories-calculator.net/Calories_Burned_By_Heart_Rate.html
8.1 calories/minute - 190 pounds.
7.5 calories/minute - 255 pounds (your numbers).
6.5 calories/minute - 326 pounds.
Okay, I did that website, and it said I would only burn about 3.59 calories per minute with a heart rate of 109 BPM. I then looked at the formula they are using:
(age*.074 + kg*.1263 + hrmBPM*.4472 -20.4022) * time / 4.184
Using this formula, entering the exact same stats, it gave me a calories burned per minute of 11.07 for my stats. I played around in Excel to see where the discrepency is coming in, and it appears that the calculator, for some reason, is SUBTRACTING the (kg*.1263) part instead of adding it. Maybe the HRM is doing something similar?
Conversely, using the calculations for male seems to be match up with the calculator and with the formula. I think there must be a glich somewhere because logic tells me that a person weighing 2x what another person does would burn more calories if their HR and ages and sexes were the same, no matter what the other factors.
ETA: Just found this same formula on a Livestrong article, however it does have that you subtract the weight and not add it. The men's formula adds the weight on the Livestrong article. I'm not understanding why a man's caloric burned would be positively effected by the weight but a woman's would be negatively effected? Granted, men generally have more LBM, but having more weight is still going to have a positive effect on caloric burn, right? Am I missing something here?
yes, something is wrong to be certain. still no word from Polar. Great customer service. sigh.0
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