Polar FT4 accuracy problems.

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scarletspy
scarletspy Posts: 170 Member
in Fitness and Exercise
I just bought my first HRM - Polar FT4 - off of ebay. I haven't used it during exercise yet but I've had it on to get a read on my resting heart rate. Problem is, it saying my resting heart rate is 116-120. I've measured manually by taking my pulse for 10 seconds and multiplying by 6 and I usually get a reading of 84-96 bpm. I've tried moving the strap around. I made sure the electrodes were wet and the strap is tight enough but I'm still about 116 bmp. The only time I've gotten a reading of under 100bpm is when I bent in half and the middle of the strap is digging right into me.

Am I doing something wrong? Or do you think I've been sold a dud monitor? How much would this gap between my actual heart rate and my reading on the monitor affect calorie burn. Would it make a huge difference accuracy wise?

Replies

  • Toddrific
    Toddrific Posts: 1,114 Member
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    Polar has a forum that you might want to peruse, I think others have similar problems.

    http://forum.polar.fi/forumdisplay.php?f=90
  • dad106
    dad106 Posts: 4,868 Member
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    First off, not supposed to wear HRM's during rest.. exercise only.

    Did you buy the HRM new or used? If you bought it used, then try washing the strap and seeing if that helps. If it's new, then try it during exercise and see what happens.
  • Ruger2506
    Ruger2506 Posts: 309 Member
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    The HRM is giving you an instant reading and you are averaging your rate over 10 seconds and then assuming it is the same for a minute by multiplying by 6. If you really want to compare you should turn the HRM trainer on and get the average rate for at least 2 minutes. At the same time you should be manually taking your heart rate for the same two minutes and then see how far off it really is.
  • sc1572
    sc1572 Posts: 2,309 Member
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    I got a PT7 for Christmas and LOVED it...until it would show my HR above 200, or stop at 0 in the middle of exercising. I emailed them with my problem, they sent me a new chest strap for free, and now it's fine! :)
  • scarletspy
    scarletspy Posts: 170 Member
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    I washed the strap and wore it during my workout on the elliptical (26.5 mins). MFP says I should have burned 570 cals but my HRM says I only burned 193 cals. I worked hard throughout and at the end I was drenched in sweat. I know there's a difference between MFP and HRM but that much? I should note I weight 316 lbs.
  • erickirb
    erickirb Posts: 12,293 Member
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    Are you wetting the transmitter on the strap?
  • kspoon5
    kspoon5 Posts: 239 Member
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    I washed the strap and wore it during my workout on the elliptical (26.5 mins). MFP says I should have burned 570 cals but my HRM says I only burned 193 cals. I worked hard throughout and at the end I was drenched in sweat. I know there's a difference between MFP and HRM but that much? I should note I weight 316 lbs.

    I find a huge big difference in calories burned per heart rate versus the MFP calculation - I would go off the reading on the HRM - for instance I workout on the elyptical for 30 minutes and burned 239 and MFP says well over 300
  • leomom72
    leomom72 Posts: 1,797 Member
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    bump..maybe i should double check mine, but i have never checked my own pulse..i depend on it without question, but now i do
  • GraemePayne
    GraemePayne Posts: 15 Member
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    If you bought the HRM used, it is quite likely that the sensor strap needs to be replaced. You will get erratic or incorrect readings when the battery is near the end of its life. Unfortunately it is a sealed unit, so you have to replace the whole strap. I have bought a couple from Amazon with good results.

    Also, some types (mostly older, with analog transmitters instead of digital) will sometimes give erratic or incorrect readings if you are using it in a crowded gym where others close by may be using one as well.
  • melbot24
    melbot24 Posts: 347 Member
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    I just purchased a brand new Polar FT4 the week before last and it's been giving me accurate readings.
    There are some things you have to be aware though...

    1) Only wear your HRM when you're exercising and trying to stay in your target HR zone - it will not give you an accurate resting HR
    2) Don't wear your HRM when you're on machines that measure your HR as well - signals can get mixed up and you will not get an accurate reading.
    3) HRM are intended to be used when you're completing cardio activities outside of the gym. i.e. crossfit, circuit training, running, bicycling, etc.
    4) Wet the chest strap before you put it on; EVERYTIME. Also, rinse and clean your chest strap after every use
  • KelseyDawn84
    KelseyDawn84 Posts: 129 Member
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    What happens if you take your RHR on your own for a full minute?... That may reduce the 20% deiscreprency between the two measurements.
  • scarletspy
    scarletspy Posts: 170 Member
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    The monitor was an unwanted present and was apparently unused.
    I find a huge big difference in calories burned per heart rate versus the MFP calculation - I would go off the reading on the HRM - for instance I workout on the elyptical for 30 minutes and burned 239 and MFP says well over 300

    I know, but it's a difference of almost 400 cals. Just seems like a low burn for 25 minutes. Even the elliptical said I burned over 200 cals.
  • dad106
    dad106 Posts: 4,868 Member
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    I just purchased a brand new Polar FT4 the week before last and it's been giving me accurate readings.
    There are some things you have to be aware though...

    1) Only wear your HRM when you're exercising and trying to stay in your target HR zone - it will not give you an accurate resting HR
    2) Don't wear your HRM when you're on machines that measure your HR as well - signals can get mixed up and you will not get an accurate reading.
    3) HRM are intended to be used when you're completing cardio activities outside of the gym. i.e. crossfit, circuit training, running, bicycling, etc.
    4) Wet the chest strap before you put it on; EVERYTIME. Also, rinse and clean your chest strap after every use

    Number 1 correct.. sort of. It will tell your resting heart rate before you start exercising.

    Number 2 is way off.. You can wear HRM's on a treadmill, bike or elliptical. If someone is near you though with an HRM and your HRM is not coded, then it can get mixed up with theirs.

    Number 3 is again way off... HRM's are meant for steady state cardio inside and outside the gym(Ie running, walking, biking, etc). Things like Crossfit and Circuit training they are not useful for because weights are involved and HRM's are not accurate for strength training.

    Number 4 is pretty spot on.. don't need to rise and clean after every use but every 5 uses.

    To OP:
    How fast were you going? I mean if you were going at a pretty decent pace, then I could see it being more but if you weren't then, it may be correct.
  • scarletspy
    scarletspy Posts: 170 Member
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    To OP:
    How fast were you going? I mean if you were going at a pretty decent pace, then I could see it being more but if you weren't then, it may be correct.

    I was going between 55-65. I was going as fast as I could but I'm new to the elliptical so I'm not sure if that's an okay speed or not.
  • dad106
    dad106 Posts: 4,868 Member
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    To OP:
    How fast were you going? I mean if you were going at a pretty decent pace, then I could see it being more but if you weren't then, it may be correct.

    I was going between 55-65. I was going as fast as I could but I'm new to the elliptical so I'm not sure if that's an okay speed or not.

    55-65 is pretty good.. did you have any resistance?

    I mean the other part is, could it have slipped at all and lost contact? If so, that can affect it.. make sure you have really good contact and if still doesn't improve then replace the battery in the transmitter and see if that helps.
  • shannonkk
    shannonkk Posts: 192 Member
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    Best time to get resting heart rate for me, is after I wake up in the morning. I noticed if I walk around and do things all day my rhr goes from 59/60 to anywhere from 70 to 85. If I lay day on the floor and put my feet up on the couch I can get it to go down alot, but at the end of a normal day lile working or just standing up it tends to stay around the high 60s or 70s. 250 calories for 30 minutes on the elliptical is about right on. Try doing a minute on low and a minute on level 5 and keep doing that for 30 minutes. It makes my calories burned a little higher than 250, lilke around 320, or wear a back pack with light weights in it while you ride. The more I get used to my workout, the less calories I burn. One more thing, I noticed that the higher my heart rate is when starting the hrm, the less calories I burn. I don't know much about the hrm or resting hear rate or if I am even using it correctly, but this is just what I have noticed.
  • catm805
    catm805 Posts: 14
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    Huge diff in cals burned from ft4 and MFP...42 with polar and 99 with MFP

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