Polar HRM monitoring heart rate wrong?

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tequierosince06
tequierosince06 Posts: 101 Member
in Fitness and Exercise
I have a question. My friend and I both have the Polar FT 60 chest strap heart rate monitor and my friend feels her monitor is off. I wanted to ask the question to get some insight into what you guys think and if you are familiar with Polar, can you help us figure out if her watch is on a wrong setting or if it was set up wrong.

My friend is 2inches shorter than me and about 15lb lighter than I am, but also 10 years older than me. She has been working out 5-6days a week for a little over a month now, before she was working out intermittently but the past month has been consistent work. She does workout videos that have both cardio with weights and sometimes just cardio. She works out for about 45min-1hour. The HRM shows her average heartrate is 130 sometimes and max for the workouts are around 145.
She said she is huffing & puffing when her heart rate is in that 140 range.
For me, I am huffing and puffing when my heart rate is in 170-180 range. So for this reason we feel like something might be off. I am taller & heavier than her but also slightly more fit and have been working out consistently for the last 6 months or so, but intermittently for the last year. The fact that she is more out of shape should make her heart rate climb higher and she should burn more calories, right? Is it possible that blood pressure may play a factor? Her blood pressure is on the low side.

Also we DO know that HRM calorie estimation is just an estimation and not completely accurate (for me I log about 25% of the actual estimation). But for her heart rate being in the 130-140 range, this means shes in zone 1 of her heart rate and her calorie burn is accurate for that heart rate. Example: Cardio + weights workout (mostly cardio, def not typical weight training) for 45 min, she burned 254 calories, heart rate max was 147, avg 120bpm.

Also keep in mind that we haven't done the same workout together at the same time while using the watch, we plan to do this soon since we are suspecting something may be off. We are also considering switching watches, I use hers and she use mine to see if it still reads similar with my watch.

Is there any setting we need to check to make sure the monitor is monitoring her heart rate correctly? Her age, weight, and height are entered correctly. Any reason you can think of that would cause the HRM to read hear rate inaccurately? Im curious to find out if her heart rate really is within the 130-140 range, if this is accurate then there is nothing wrong w the hrm.

Replies

  • cwolfman13
    cwolfman13 Posts: 41,874 Member
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    It's probably right. I used to huff and puff walking my dog around the block and my HR never was above 120. As I got in better shape I was able to elevate my HR more because I was able to do more work without huffing and puffing.

    130-140 BPM is pretty normal for me for a moderately paced endurance road or trail ride, which is most of my riding...definitely not huffing and puffing, but I used to. I only get to that point now if I'm doing something like hill repeats are doing an all out 12K time trial in which my HR is between 150 and 160 sustained for about 38-40 minutes...I could have never reached that for any sustained period of time when I was just a month or so into fitness.

    I doubt it would have anything to do with blood pressure, but resting HR can make a difference. If her starting point is lower than yours then it would take more effort to get her HR up...if your starting point is higher, your HR during exercise is likely to be higher.
  • tequierosince06
    tequierosince06 Posts: 101 Member
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    cwolfman13 wrote: »
    but resting HR can make a difference. If her starting point is lower than yours then it would take more effort to get her HR up...if your starting point is higher, your HR during exercise is likely to be higher.

    Good pt about resting heart rate.
  • Lietchi
    Lietchi Posts: 6,121 Member
    edited September 2020
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    tequierosince06 wrote: »
    cwolfman13 wrote: »
    but resting HR can make a difference. If her starting point is lower than yours then it would take more effort to get her HR up...if your starting point is higher, your HR during exercise is likely to be higher.

    Good pt about resting heart rate.

    Max heart rate can also vary from person to person, by the way.
    My cousin (similar stats) does runs at an average heart rate that is above my max heart rate. It's all very individual.

    And higher heart rate/being more out of shape doesn't mean higher calorie burn. That's just one of the pitfalls of HR based calorie burn estimates.
  • AnnPT77
    AnnPT77 Posts: 32,170 Member
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    There is a lot of variation in HR even among people of the same size, age and fitness level. I'd be surprised to see a similar heart rate response from people of different size, age, fitness level and doing different workouts. It would be an amazing coincidence if they were the same or similar.

    Yes, all other things being equal (which they aren't in this case), I'd expect the fitter person's heart rate to be lower when doing the same workout at the same intensity. But there's no guarantee here that you're working out at similar intensity. Huffing and puffing varies with fitness level. If I go out rowing with a high-level collegiate rower, s/he will be breathing easy when I'm panting, at a similar exertion level. If I row instead with a brand new beginner who has no history of other significant cardiovascular exercise, s/he will be winded before I will. (I have done something similar to these experiments!) The implication is that your friend may be panting at a lower level of exertion (one where you'd be breathing easy), and not even be able to reach the intensity level where you're breathing hard.

    Furthermore, HR response during any exercise involving weights is not comparable to a workout not involving weights (because HR goes up during strength activities at least partly for reasons involving internal body pressure, not oxygen demand as would be the cause during more pure cardiovascular exercise).

    There are just too many variables involve here: This is not comparing apples to oranges, it's comparing apples to roller skates, almost.

    Maybe let her try using your HR monitor, you try hers, if that doesn't screw you up too much? The other option is to manually check HR and compare (though the timing would be slightly different, you'd know if it was in the ballpark). The usual routine would be to manually check and count your pulse for 10-15 seconds, then multiple by 6 or 4 to get a BPM estimate.

    And, yes, a much lower heart rate will tend to make a HRM estimate fewer calories. If it were same-sized/age people doing the same exercise at the same intensity (like jogging a mile on the same course at the same pace), then the calorie estimate for one of them would be wrong. Well, more likely the estimate for both would be wrong, but probably wronger for one than the other. Which one? Hard to know . . . .

    I think you're expecting too much of both HRs and HRMs. They're close enough in practice for most people to use for calorie estimates for most exercises, but they're not oracular.

    Good to read, written a while back, but the fundamentals are still true:

    https://www.myfitnesspal.com/blog/Azdak?month=201003
  • MikePfirrman
    MikePfirrman Posts: 3,307 Member
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    Polar was always much higher for me. I didn't think it was accurate at all. I gave up on Polar but I've heard their latest products are better. I'm just gun shy.
  • AnnPT77
    AnnPT77 Posts: 32,170 Member
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    MikePfirrman wrote: »
    Polar was always much higher for me. I didn't think it was accurate at all. I gave up on Polar but I've heard their latest products are better. I'm just gun shy.

    Without arguing your experience (because these things can be weirdly idiosyncratic 😉 ), my old Polar (chest belt with watch from several years back, don't remember model number) produced average and max HRs that were about the same as my Garmin Vivoactive 3 (with a chest belt synched), for similar workouts. The low-end Polar watch only gave me average and max, not a moment to moment HR graph, so that's all I can compare. The calorie estimates differed some (in different directions for different workouts!), but that's to be expected, I think.

    I'm assume it's clear that I don't think my experience with Polar generalizes to the OP, since I don't have any trouble believing that both your and my experiences are accurately recounted. 😆
  • tequierosince06
    tequierosince06 Posts: 101 Member
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    AnnPT77 wrote: »
    MikePfirrman wrote: »
    Polar was always much higher for me. I didn't think it was accurate at all. I gave up on Polar but I've heard their latest products are better. I'm just gun shy.

    Without arguing your experience (because these things can be weirdly idiosyncratic 😉 ), my old Polar (chest belt with watch from several years back, don't remember model number) produced average and max HRs that were about the same as my Garmin Vivoactive 3 (with a chest belt synched), for similar workouts. The low-end Polar watch only gave me average and max, not a moment to moment HR graph, so that's all I can compare. The calorie estimates differed some (in different directions for different workouts!), but that's to be expected, I think.

    I'm assume it's clear that I don't think my experience with Polar generalizes to the OP, since I don't have any trouble believing that both your and my experiences are accurately recounted. 😆

    First, thanks you always give good insight & my 2 cents is my polar model is one of the older models forsure just because their newer models are pretty pricey. I got mine second hand very gently used and I prefer it to my apple watch. I compare my apple watch heart rate to my polar and my polar numbers look better as in I feel my heart rate level is accurate for the amount of effort & my apple calories burned is a lot higher than my polar I know apple watch isnt super accurate but its the only thing I have to compare it to. Maybe one day I will treat myself and upgrade but that wont be anytime soon. I allowed myself one upgrade recently & that $$ went to my new power block dumbbells.
  • tequierosince06
    tequierosince06 Posts: 101 Member
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    Lietchi wrote: »
    tequierosince06 wrote: »
    cwolfman13 wrote: »
    but resting HR can make a difference. If her starting point is lower than yours then it would take more effort to get her HR up...if your starting point is higher, your HR during exercise is likely to be higher.

    Good pt about resting heart rate.

    Max heart rate can also vary from person to person, by the way.
    My cousin (similar stats) does runs at an average heart rate that is above my max heart rate. It's all very individual.

    And higher heart rate/being more out of shape doesn't mean higher calorie burn. That's just one of the pitfalls of HR based calorie burn estimates.

    Yes. I thought about this also, I also calculated her max heart rate. Mine is190, hers is 183.
  • AnnPT77
    AnnPT77 Posts: 32,170 Member
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    tequierosince06 wrote: »
    Lietchi wrote: »
    tequierosince06 wrote: »
    cwolfman13 wrote: »
    but resting HR can make a difference. If her starting point is lower than yours then it would take more effort to get her HR up...if your starting point is higher, your HR during exercise is likely to be higher.

    Good pt about resting heart rate.

    Max heart rate can also vary from person to person, by the way.
    My cousin (similar stats) does runs at an average heart rate that is above my max heart rate. It's all very individual.

    And higher heart rate/being more out of shape doesn't mean higher calorie burn. That's just one of the pitfalls of HR based calorie burn estimates.

    Yes. I thought about this also, I also calculated her max heart rate. Mine is190, hers is 183.

    Max heart rates aren't really calculated, only estimated. To know, they need to be tested. The age formulas are inaccurate for a fair percentage of people. By 220 - age, mine should be 156. It's actually more like 180. There are other age based formulas, but any I've seen is inaccurate for me (low), and I'm not unique in this. It isn't mostly fitness, either IMU - it's mostly genetics. Active athletes reportedly experience slower age-related decline in HRmax, but different people are in genetically different places to start with, even at similar fitness history.
  • Jruzer
    Jruzer Posts: 3,501 Member
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    tequierosince06 wrote: »
    Lietchi wrote: »
    tequierosince06 wrote: »
    cwolfman13 wrote: »
    but resting HR can make a difference. If her starting point is lower than yours then it would take more effort to get her HR up...if your starting point is higher, your HR during exercise is likely to be higher.

    Good pt about resting heart rate.

    Max heart rate can also vary from person to person, by the way.
    My cousin (similar stats) does runs at an average heart rate that is above my max heart rate. It's all very individual.

    And higher heart rate/being more out of shape doesn't mean higher calorie burn. That's just one of the pitfalls of HR based calorie burn estimates.

    Yes. I thought about this also, I also calculated her max heart rate. Mine is190, hers is 183.

    Unfortunately, the max heart rate calculation (220-age) is fairly useless. My HR during routine exercise goes higher than my so-called maximum.

    There are other links and studies, but this one seems as good as any:
    https://www.prevention.com/fitness/fitness-tips/a20463570/maximum-heart-rate-formula-usually-incorrect/

    Her are a few MFP threads on it:
    https://community.myfitnesspal.com/en/discussion/comment/42245821#Comment_42245821
    https://community.myfitnesspal.com/en/discussion/comment/45220285#Comment_45220285



    Also - if she has worries about her HRM, why not do a direct comparison of what the HRM measures vs what she can measure with a stopwatch and fingers on the wrist?
  • sijomial
    sijomial Posts: 19,811 Member
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    Can't you just check her/your pulse manually to confirm it's reading correctly?
    Or alternatively take it in turns to wear both watches.

    That two people have wildly different HR doing the same exercise is entirely likely and that tells you very little about their actual calorie burn. After 6 years of fairly serious cycling I've got a very good pump and am blessed with oversize lungs - I burn more calories at a lower heartrate both acrosss my demographic and also compared to myself 6 years ago.

    Years ago I had an FT60 and managed to calibrate it against accurate calorie burns from a bike's power meter by adjusting the settings but that only worked for steady state riding. For interval work it over-estimated by about 25%.

    You don't estimate Max HR if you really want to know - you test it.
    There are self test routines available as well as sports lab ones but beware they are extreme.
    For a very rough idea push as hard as you can until you have to stop and then add 5bpm to the number you see.

    Ignore calorie burn estimations from your FT60 during weight training - it can't make sense of the spikes in HR that are nothing to do with oxygen demand.
  • acpgee
    acpgee Posts: 7,624 Member
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    I have an irregular heart rate and my polar was inaccurate as a result. Sometimes my heart rate would suddenly double for a minute or two and then drop back down.

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