Should I trust my hrm?

jenniferdances1
jenniferdances1 Posts: 86 Member
edited November 11 in Fitness and Exercise
I just got a Polar FT4 hrm. I've used it twice and both times the calories burned readings I'm getting on it are WAY higher than my treadmill and every other calorie calculator I put my info into. Like today I ran/walked on the treadmill for 30 minutes. Treadmill says I burned 220 calories but the hrm says I burned 358 calories. I don't know which to trust!

Replies

  • laineylynnfit
    laineylynnfit Posts: 369 Member
    I have read that the machines aren't very accurate when calculating calories burned. Personally, I go with my HRM (I have a GARMIN FR70) and it's supposed to be pretty accurate. I assume you Polar FT4 does come with a chest strap to monitor your heart rate?
  • jenniferdances1
    jenniferdances1 Posts: 86 Member
    Yes, it has a chest strap. I'm mostly just worried because everything I read on here said that people's hrm's were giving them lower numbers than the machines but mine is giving me higher numbers.
  • 99clmsntgr
    99clmsntgr Posts: 777 Member
    Your heart rate monitor, particularly if it has a chest strap, is a direct measure of how hard your body is working (muscles working hard = need more oxygen = heart beats faster). Even the machines that have heart rate check by grabbing the handles (not a very accurate way to measure) are just giving you a guess at best.

    Believe your heart rate monitor. And rejoice in the fact that you earned an extra 100+ calories to eat today!
  • ncw89
    ncw89 Posts: 61 Member
    The hrm will be giving readings according to your height/weight/age stats so as long as those are close to correct then the burn ought to be pretty accurate. The machines will be using generic stats which probably wouldn't fit yours very closely so basically its a random guess! Trust the hrm :)
  • agthorn
    agthorn Posts: 1,844 Member
    Mine gave me higher numbers for some exercises too; I have a Polar FT60. I was a little skeptical at first but I've been using it for two months and still maintaining (my goal) while eating back the higher number of exercise cals.
  • jenniferdances1
    jenniferdances1 Posts: 86 Member
    Ok I feel better now. Thanks y'all!
  • Azdak
    Azdak Posts: 8,281 Member
    When it comes to walking, treadmill calorie readouts are fairly accurate--the equations used to estimate calories burned are simple and can easily be programmed into the machine (as long as you put in your weight). With running, esp at higher speeds, machines start to overestimate.

    You can't just assume, like many people do, that an HRM is the most accurate. HRMs are not precise instruments, nor are they particularly smart. HRMs do not measure calories. They measure heart rate and use algorithms to translate heart rate into an estimated calorie reading.

    However, these algorithms are only accurate under certain conditions (steady-state aerobic exercise) and if the setup information is accurate. For example a significant percentage of the population has a maximum heart rate that is 15-30 beats/min higher than what your HRM uses as the default measure. If you are one of those people, the HRM will significantly overestimate your calories, since it assumes you are working at 95%-100+% of your maximum, when you may only be at 60%-70%.

    So before you jump to any conclusions, you need to check your setup first of all.
  • Azdak
    Azdak Posts: 8,281 Member
    The hrm will be giving readings according to your height/weight/age stats so as long as those are close to correct then the burn ought to be pretty accurate. The machines will be using generic stats which probably wouldn't fit yours very closely so basically its a random guess! Trust the hrm :)

    Not always. Simple cardio exercises such as walking have a relatively fixed energy cost. In other words it takes "X" amount of oxygen to walk at 3 mph, regardless of who is doing it. HRMs are the ones that are "guessing" trying to fit your heart rate response into a predefined pattern.

    If you can't directly measure the intensity of the activity, then the HRM is usually the better choice. But for a simple activity such as walking (without holding on, and with your weight entered into the machine), the machine will be as accurate, or more accurate, than an HRM.
  • boobee32
    boobee32 Posts: 450 Member
    My polar generally gives me about 40 calories less reading than the treadmill.
  • Hollybot
    Hollybot Posts: 108 Member
    I am really out of shape, and my HRM gives me higher numbers. I am loosing weight and I eat my calories back. The logical explination I give myself is as I get in shape, my heart will beat slower and the numbers of cals burned will go down. Thats just my opinion though, I'm not a kinesiologist
  • kated930
    kated930 Posts: 132
    Did you put in your Height and Weight?? I got my HRM in September and since then I've been doing body pump and put on about 3-4 lbs that I *think* is muscle. Then my dietician told me to make sure I keep my HRM updated with my new weight, now I burn slightly more calories then I did before, so making sure your info is correct could make a difference as well.
  • amyreafleng
    amyreafleng Posts: 69 Member
    The hrm I have also reads very high. I have a higher resting heart rate so it take very little effort to be at or above target heart rate. So I just assume it is not accurate...
  • UpEarly
    UpEarly Posts: 2,555 Member
    I trusted mine, and I lost the weight I wanted to. I'm assuming that means the calories burn was pretty accurate. (I ate my exercise calories)
  • junyr
    junyr Posts: 416 Member
    This website, the labels on food, your scales you measure with, HRM's, they're all just estimates. With that being said using a chest strap HRM with your personal stats programmed into it, short of getting a lab test will be your most accurate estimate of what you burn.

    estimates based on averages....

    We all do the best we can.
  • owngoal64
    owngoal64 Posts: 22 Member
    Some HRMs can't be trusted. I have a Timex Triatholon with a chest strap and it indicates 50% greater calories burned than my old one. This with all of my statistics entered properly, etc. I looked on the web and have seen many others making the same complaints about it. The companies response is "we use a basic formula", so in other words they haven't evaluated it for accuracy at all. Cost was as much as a pretty nice Polar (I have heard they are pretty accurate)

    If you are trying to lose weight and want to be on the safe side, just don't eat back all of your calories spent exercising. Maybe allow yourself half. You will be able to tell in a few weeks how accurate your estimations are.
  • agthorn
    agthorn Posts: 1,844 Member
    However, these algorithms are only accurate under certain conditions (steady-state aerobic exercise) and if the setup information is accurate. For example a significant percentage of the population has a maximum heart rate that is 15-30 beats/min higher than what your HRM uses as the default measure. If you are one of those people, the HRM will significantly overestimate your calories, since it assumes you are working at 95%-100+% of your maximum, when you may only be at 60%-70%
    True, my calculated HRmax should be 180 but it's 201. That's only a 10% difference though, not 35-40%. But my Polar HRM allows me to set my own values, which I've done.
  • cibilbee
    cibilbee Posts: 47 Member
    Have the same hrm and that is actually around the same number I get when I run 30 min. I've been using mine for about 6 months and it's totally changed how I workout. I love it!!!
  • Nnekaschild
    Nnekaschild Posts: 26 Member
    The hrm will be giving readings according to your height/weight/age stats so as long as those are close to correct then the burn ought to be pretty accurate. The machines will be using generic stats which probably wouldn't fit yours very closely so basically its a random guess! Trust the hrm :)

    Not always. Simple cardio exercises such as walking have a relatively fixed energy cost. In other words it takes "X" amount of oxygen to walk at 3 mph, regardless of who is doing it. HRMs are the ones that are "guessing" trying to fit your heart rate response into a predefined pattern.

    If you can't directly measure the intensity of the activity, then the HRM is usually the better choice. But for a simple activity such as walking (without holding on, and with your weight entered into the machine), the machine will be as accurate, or more accurate, than an HRM.


    What about for walking on an incline of higher than 3%. Is the reading from the machine still accurate? I usually walk up to a maximum of 5-6% incline.
  • roxysaurus
    roxysaurus Posts: 1 Member
    i just started using a hrm and was a bit freaked out when it gave me higher readings. i took it to one of my friends who is a trainer and he checked everything, it was all set up right. he mentioned staying diligent about updating it but because i hadn't been as active as i use to be it will give a higher reading until i get used to working out.
  • jenniferdances1
    jenniferdances1 Posts: 86 Member
    I'm positive that all of my info is programed in correctly. I even went in after I weighed in yesterday and changed my weight from 166 to 165 just so it would be 100% accurate since I lost a pound.:) I'm just going to trust it for now. If I gain weight, well, then I'll know that was the wrong choice! lol (Hopefully that won't be the case though!!!!)
  • Azdak
    Azdak Posts: 8,281 Member
    The hrm will be giving readings according to your height/weight/age stats so as long as those are close to correct then the burn ought to be pretty accurate. The machines will be using generic stats which probably wouldn't fit yours very closely so basically its a random guess! Trust the hrm :)

    Not always. Simple cardio exercises such as walking have a relatively fixed energy cost. In other words it takes "X" amount of oxygen to walk at 3 mph, regardless of who is doing it. HRMs are the ones that are "guessing" trying to fit your heart rate response into a predefined pattern.

    If you can't directly measure the intensity of the activity, then the HRM is usually the better choice. But for a simple activity such as walking (without holding on, and with your weight entered into the machine), the machine will be as accurate, or more accurate, than an HRM.


    What about for walking on an incline of higher than 3%. Is the reading from the machine still accurate? I usually walk up to a maximum of 5-6% incline.

    If you do not hold on to the handrails for support, then yes. It's speed that causes the overestimate, not incline. The speed becomes as issue because of: more bounce in the treadmill deck, wind resistance (not much, but a little); I have also read some studies that looked at the equations themselves and suggested they overestimate oxygen uptake (which means calories) at faster speeds.
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