Are HRMs truly accurate??

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MissVamp13
MissVamp13 Posts: 53
in Fitness and Exercise
Hi everyone :)
This may seem like an odd topic to you all but I wanted some feedback. I currently own a Polar FT4 hrm and when I post my calorie burn results after a workout, I got told not to believe the burn that I am told as they can be inaccurate.. What do you all think?

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  • __Di__
    __Di__ Posts: 1,632 Member
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    I have the Polar FT4, great little gadget!

    Regarding the accuracy, if you have put all your details into the watch, then it will be as accurate as possible, but nothing is 100% accurate, not the HRM nor the calorie burns that are shown on cardio machines such as treadmills.

    Put it this way, it is definitely better than nothing at all and people that say they are not accurate, what do they suggest you use?

    Don't forget though, the HRM is only meant to be used for elevated heartrates during cardio, it will not be accurate during weights or for stuff like wearing around the house all day - perhaps it was this aspect those people meant when they said HRMs are not accurate.
  • GetSoda
    GetSoda Posts: 1,267 Member
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    It's only accurate for heart rate.
    Put it this way, it is definitely better than nothing at all and people that say they are not accurate, what do they suggest you use?

    Consistent calorie levels and expenditure, followed by determining your average (Gross, not net) food intake for over a two week period, and adjusting up or down based on results.
  • MissVamp13
    MissVamp13 Posts: 53
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    What I like about using mine, is the moment I put it on I know theres no going back and that i MUST get moving :)
  • wtw0n
    wtw0n Posts: 1,083 Member
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    Nothing is 100% accurate and there are huuuuge differences between different heart rate monitors. Polar FT4 and FT7 are quite popular, but they are not one of the best Polar heart rate monitors.


    Here's an example:
    Workout: Insanity - Max Interval Circut (duration 59:44, 167cm/88.8kg, female, 26yo)
    Polar FT7: avg heart rate 156, max heart rate 173, calories burned 654
    Polar RCX3 (features VO2 Max): avg heart rate 158, max heart rate 174, calories burned 516
  • ebr250
    ebr250 Posts: 199 Member
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    I was wondering this too, thanks for asking. I also just purchased the Polar FT4. I put all my details into the watch, but I have a hard time believing the calories burned figures are accurate since the numbers are so high. I don't expect 100% accuracy, of course, but what degree of accuracy should I expect?
  • brixtonbanner
    brixtonbanner Posts: 71 Member
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    I have a polar RCX5 HRM
    On a bike ride I also take my phone which is running the Runtastic road-bike App
    After I get in and plug everything up to the laptop the Polar HRM always says I have burnt more calories than Runtastic does.
    On a 20K ride it's somewhere between 30 and 200 calories different.

    I could get hung up on the inaccuracy and discrepancy between the two but I don't

    I think that I will let the Runtastic app modify my MFP calories as I did before the HRM
    If the HRM is right and Runtastic wrong then I'll hopefully drop the weight a bit quicker
    If the other way round then I'm still doing OK
    If I worry about it?
    I'll buy a big bar of Chocolate, a litre of coke and a family bag of crisps
  • MrsGriffin67
    MrsGriffin67 Posts: 485 Member
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    I own a BodyMedia LINK. It is a registered FDA device and is proven to be >90% accurate. Just sayin'
  • toddis
    toddis Posts: 941 Member
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    In this specific study ~70ish%
    http://www.ncbi.nlm.nih.gov/pubmed/21178923

    I think Polar states its around 75%, but can't find the link.

    I believe if you are using the same device during training, even if it overestimates, you can adjust accordingly.
  • __Di__
    __Di__ Posts: 1,632 Member
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    It's only accurate for heart rate.
    Put it this way, it is definitely better than nothing at all and people that say they are not accurate, what do they suggest you use?

    Consistent calorie levels and expenditure, followed by determining your average (Gross, not net) food intake for over a two week period, and adjusting up or down based on results.

    I cannot guarantee consistent expenditure, my day-to-day life varies enormously.

    Besides which, how does that determine calories burned?
  • brixtonbanner
    brixtonbanner Posts: 71 Member
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    I believe if you are using the same device during training, even if it overestimates, you can adjust accordingly.

    Excuse me being a bit thick but how?

    If a bit of kit says I'm burning 500 calories but I'm only burning 350 how do I know?
    Wait till my trousers are so loose they fall down
    multiply the volume of laughter ensuing in Db by 25 and that's the number of calories I should add to each run?

    Sorry got a bit surreal there
  • GetSoda
    GetSoda Posts: 1,267 Member
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    It's only accurate for heart rate.
    Put it this way, it is definitely better than nothing at all and people that say they are not accurate, what do they suggest you use?

    Consistent calorie levels and expenditure, followed by determining your average (Gross, not net) food intake for over a two week period, and adjusting up or down based on results.

    I cannot guarantee consistent expenditure, my day-to-day life varies enormously.

    Besides which, how does that determine calories burned?

    So maybe you need a 3 or 4 week average? And it doesn't determine calories burned. It determines the relationship between food intake, activity, and weight/gain/loss in the most effective way possible.

    of course, if your goal is just posting up big numbers on the news feed, the above doesn't help you at all.
  • mrloserpunk
    mrloserpunk Posts: 92 Member
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    In this specific study ~70ish%
    http://www.ncbi.nlm.nih.gov/pubmed/21178923

    I think Polar states its around 75%, but can't find the link.

    I believe if you are using the same device during training, even if it overestimates, you can adjust accordingly.

    ....man that's disappointing :-( if its off by 25%.... It's almost useless :-(
  • __Di__
    __Di__ Posts: 1,632 Member
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    It's only accurate for heart rate.
    Put it this way, it is definitely better than nothing at all and people that say they are not accurate, what do they suggest you use?

    Consistent calorie levels and expenditure, followed by determining your average (Gross, not net) food intake for over a two week period, and adjusting up or down based on results.

    I cannot guarantee consistent expenditure, my day-to-day life varies enormously.

    Besides which, how does that determine calories burned?

    So maybe you need a 3 or 4 week average? And it doesn't determine calories burned. It determines the relationship between food intake, activity, and weight/gain/loss in the most effective way possible.

    of course, if your goal is just posting up big numbers on the news feed, the above doesn't help you at all.

    So I am supposed to wait 4 weeks :laugh: :laugh: :laugh:

    I am doing fine thanks :laugh: :laugh: :laugh: :laugh:
  • toddis
    toddis Posts: 941 Member
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    I believe if you are using the same device during training, even if it overestimates, you can adjust accordingly.

    Excuse me being a bit thick but how?

    If a bit of kit says I'm burning 500 calories but I'm only burning 350 how do I know?
    Wait till my trousers are so loose they fall down
    multiply the volume of laughter ensuing in Db by 25 and that's the number of calories I should add to each run?

    Sorry got a bit surreal there

    Many people suggest you only eat back say ~50% of your exercise calories. If all variables remain constant and results aren't as expected, you would adjust accordingly.

    While a HRM may be inaccurate, it may be less inaccurate than a basic formula based on just age and weight, etc.
  • __Di__
    __Di__ Posts: 1,632 Member
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    It's only accurate for heart rate.
    Put it this way, it is definitely better than nothing at all and people that say they are not accurate, what do they suggest you use?

    Consistent calorie levels and expenditure, followed by determining your average (Gross, not net) food intake for over a two week period, and adjusting up or down based on results.

    I cannot guarantee consistent expenditure, my day-to-day life varies enormously.

    Besides which, how does that determine calories burned?

    So maybe you need a 3 or 4 week average? And it doesn't determine calories burned. It determines the relationship between food intake, activity, and weight/gain/loss in the most effective way possible.

    of course, if your goal is just posting up big numbers on the news feed, the above doesn't help you at all.

    This isn't what this thread is about. I am not having problems losing weight. I like to have a calorie burn and know what it is, I do not even eat all my calories back.

    No, my goal is NOT just posting up big numbers on the news feed at all.

    3 or 4 week average? Why? I just said, I am unable to have a consistent expenditure due to my day to day life being enormously different and variable, what is there to not understand in that statement.

    I am fine with all my stuff, but this thread was asking Are HRMs truly accurate it is NOT about TDEE or anything else. Stick to the subject that was asked, don't hijack the thread for your own agenda.
  • brixtonbanner
    brixtonbanner Posts: 71 Member
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    My apologies for diverting the thread from it's topic
  • __Di__
    __Di__ Posts: 1,632 Member
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    My apologies for diverting the thread from it's topic

    huh?? you didn't divert it :laugh: :flowerforyou:
  • STrooper
    STrooper Posts: 659 Member
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    A well documented program with accurate profile, HR, and GPS data can give you a reasonable estimate. If you are really concerned, take your HRM with you and have a metabolic test done to determine whether the HRM and the program you are using are giving you reasonably accurate numbers. A metabolic test will put your body under load and measure your heart rate, you respiration rate at various loads and the composition of what you exhale (CO2 and O2).

    For example when running the hills around here, I get some pretty high values (hiking with a heavy pack will increase load and also show up with a higher burn rate without me changing my total weight to include the pack). But when I am walking around downtown on relatively flat ground, my calorie burn rate is really quite a bit less than the 100 calorie/mile average. Mine is like 65-70 calories per mile unless I walk pretty fast (like 4.5 mph).

    I am using iCardio as my HRM conversion program because it supports my HRM, it is very well documented and they are open about the formulas they use to calculate rate of energy expenditure. They also provide a set of tests to fine tune your program. But not every monitor is supported and there are a number of complaints about the costs associated with purchasing HRM support

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