Inaccurate calories via HRM

anzura
anzura Posts: 171
edited September 27 in Fitness and Exercise
Just an FYI...
Here's a good example of how you can't really trust your HRM to give you accurate calories burned.

Last weekend I ran a half marathon. Here are the stats from my HR monitor:

13.1 miles
2 hours 16 mins
average HR: 165
max HR: 198
calories burned: 1504

Today I went on a leisurely bike ride. Here are the stats from my HR monitor:

25 miles
2 hours 7 mins
average HR: 115
max HR: 158
calories burned: 1500

There is NO WAY I burned as many calories today as I did on my half marathon. Less time and a much lower heart rate! My guess is it's closer to 800.

BTW: This is from a Garmin Forerunner 305 with the chest strap.

Replies

  • cmriverside
    cmriverside Posts: 34,449 Member
    agreed. I just wanted to say, nice work on the marathon and the bike ride!!
  • Onesnap
    Onesnap Posts: 2,819 Member
    Look online. If it's an HRM by polar with a chest strap it does not lie. Best brand of HRMs out there.
  • IrishHarpy1
    IrishHarpy1 Posts: 399 Member
    And don't forget -- going over your maximum calorie burn HR will put your body into conservation mode, and you won't burn as many calories.
  • ChRiStA_1983
    ChRiStA_1983 Posts: 380 Member
    If this helps at all, I have a Garmin 410 with a heart rate monitor and chest strap, AND a Polar F4....

    I wear the F4 for indoor use (cardio at the gym, or on my home treadmill), and the Garmin for all of my outdoor running...

    I find that the Garmin always shows that I burned WAY less calories than the Polar one does! But I figure it's better to UNDERestimate calories burned, than overestimate!
  • skeene07
    skeene07 Posts: 57 Member
    FYI...the lower series gamins do not calculate calories burned based off of heart rate! Your HR for the 305model is for information purposes only. Calories burned are base off of height, weight, time, etc. like other website estimations!

    I have the 305 and also the 410cx...the 410 DOES base calories burned off of heart rate.!
    You can probably find out this info on their website :)
  • skeene07
    skeene07 Posts: 57 Member
    Oops...I meant that I have the 405cx :)

    It's says on the website that the 405cx Has heart-rate based calorie computation...the lower models do not.

    Hope that helps.
  • anzura
    anzura Posts: 171
    Well that fricken explains a lot! Guess its time for a upgrade and I can stop wearing that annoying strap for now. Thanks for the info.
  • BigBoneSista
    BigBoneSista Posts: 2,389 Member
    That kinda sucks. I was over here scratching my head thinking maybe your garmin was on its way out. Why doesn't it utilize the strap if it came with one?
  • anzura
    anzura Posts: 171
    That kinda sucks. I was over here scratching my head thinking maybe your garmin was on its way out. Why doesn't it utilize the strap if it came with one?

    Well my gander is it's just a training tool for runners. There's a lot of people who train by heart rate instead of pace. If I want to stay in a certain HR zone I can set up my watch to beep at me if my HR gets too high or low. I just don't understand how hard it would have been to just add an accurate calorie count in there somewhere.
  • capricorn57
    capricorn57 Posts: 7 Member
    I have a Sportline HRM and wonder if the calories burned are too high as well. What I notice is that when my HR is at 90%+ in my target zone range, the calorie counter seems to roll. I'll burn hundreds of calories during the time (usually 30 minutes) my HR is at 90%. When my HR is in the 50-70% range of my target zone, the calorie counter hardly moves. I've been figuring half of whatever the HRM says I burned but if I am burning more, I'd like to know.
  • skeene07
    skeene07 Posts: 57 Member
    That kinda sucks. I was over here scratching my head thinking maybe your garmin was on its way out. Why doesn't it utilize the strap if it came with one?

    Well my gander is it's just a training tool for runners. There's a lot of people who train by heart rate instead of pace. If I want to stay in a certain HR zone I can set up my watch to beep at me if my HR gets too high or low. I just don't understand how hard it would have been to just add an accurate calorie count in there somewhere.

    YEP :)
  • JohnnyNull
    JohnnyNull Posts: 294 Member
    Yes, thank you! This why I tell people to save their damned money.
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