Heart Rate Monitor-Can it be wrong?

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This week I have started C25K. I have a Timex HRM with a chest strap. The past two times I've logged my entire time under walking. Because I'm not quite up to an average of 5mph yet. And I don't want to take the time to split it up between walking and jogging.

Today if I logged my time under:
walking(4.5 mph) mfp for 38 mins=195 calories
jogging (5 mph) mph for 38 mins= 248 calories
My HRM says I burned for 38 mins=346 calories

There is a big difference what my HRM says compared to even if I log it under jogging(for the whole time). Can HRM be wrong? Which number would you go by?

Replies

  • CaptainAmerica1970
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    How much do you weigh? are you male or female?
  • melissabell1984
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    I just recently purchased a Sunnto M4, (I LOVE IT!). Yesterday I did a Very Brisk Walk for 31min. According to here I should have only burned about 144cal ... according to my HRM I burned 247. I think on here it's very general, where as your HRM monitors YOU ... but I'm no expert!
  • sambones76
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    As long as your weight is correct in the HRM, it should be more accurate.
  • JCPruitt
    JCPruitt Posts: 53
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    The HRM takes you level of exertion into account. I am guessing, like mine, you had to enter your weight and height as well as stride. Make sure your stride is correct.
  • CaptainAmerica1970
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    If you are heavier you burn more than a lighter person. I would base it off of your HRM. you can adjust the numbers on your web site. In your HRM make sure you put in the correct data, age, gender, weight, etc.
  • esf215
    esf215 Posts: 6 Member
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    IM having the same question. Last night my hrm said i burned 861 on the treadmill but the website said i burned 506 in 60 min.. I'm trying to decide which one to go with
  • momof4Oneal
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    If your setttings have accurate weight/height etc. information than I would defintely go by your HRM. Your body can fluctuate day by day on how many calories you burn. For instance I wear a Polar HRM & I can do the same exact workouts at the gym & my calories are different each day. Plus everybody's body is different! I always go by my HRM & just add my calories burned from my watch each day I work out! Hope that helps!!!
  • TXHunny84
    TXHunny84 Posts: 503 Member
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    Does your HRM let you enter age weight, gender, height and resting heart rate?....If it doesn't then it's probably not too accurate.... I always enter the smaller numbers to be safe that I am not over estimating my calorie burn.
  • sarahnicolexoxo
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    MFP can be off by aot or a little when you log your exercise in. That is why I always tell people to buy a HRM with a cheststrap for a more accurate reading. I always use my HRM when working out and I have noticed that the machines at the gym are off by a lot as well as what MFP says. I would always trust your HRM, especially when you have entered your weight into it.
  • catwrangler
    catwrangler Posts: 918 Member
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    For instance I wear a Polar HRM & I can do the same exact workouts at the gym & my calories are different each day. Plus everybody's body is different!

    I don't have a HRM (yet!) but I agree with the above statement. I use the nautilus machines at the gym and if I work out in the evenings I have a hard time getting my HR over 115, but when I work out in the mornings I can get it up to 140 (according to the machines). I am 218 and 5'6" female
  • 27strange
    27strange Posts: 837 Member
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    In general, HRM will be way more accurate than MFP. MFP is a generalization based on your age, height, weight. HRM uses the same age, height, weight but is counting your heart beats per minute and is factoring your calorie burn from your heart rate level.

    And its true that different days for the same exercises I burn differently according to my HRM. This has to do with the elevation of my heart rate and the intensity I put forth.

    HRMs are not 100% accurate either though. They are susceptible to errors as well. One thing I notice is that when I work out outside in intense heat and humidity the readings are way higher. I think the humidity plays with the heart rate reading.
  • dad106
    dad106 Posts: 4,868 Member
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    This week I have started C25K. I have a Timex HRM with a chest strap. The past two times I've logged my entire time under walking. Because I'm not quite up to an average of 5mph yet. And I don't want to take the time to split it up between walking and jogging.

    Today if I logged my time under:
    walking(4.5 mph) mfp for 38 mins=195 calories
    jogging (5 mph) mph for 38 mins= 248 calories
    My HRM says I burned for 38 mins=346 calories

    There is a big difference what my HRM says compared to even if I log it under jogging(for the whole time). Can HRM be wrong? Which number would you go by?

    Honestly, return the TImex.. They are crap HRM's and give a very overestimated calorie burn. I know because I had one that you could only enter weight and max heart rate into, and to get an accurate reading you need to enter everything.. weight, height, gender, age and Vo2max(which Timex does not take into account at all).

    If your gonna log it, go with the HRM but don't eat all the calories back.
  • dieselbugparrot
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    Thank you All! I'll take the calories burned from my HRM with a grain of salt.

    It does have a chest strap. But it only ask for: lower target zone limit, upper target zone limit, max heart rate and weight. Not age, sex or any of the other things you all have mentioned.

    Thanks again for your help.