Difference in cals burned with HRM/CardioTrainer/MFP

dordec78
dordec78 Posts: 11 Member
in Fitness and Exercise
I have the Polar FT7, and have only used it on 3 workouts so far. It seems to be pretty accurate with my resting rate, but I'm not sure how accurate it is when I am walking or running.

I did a combo of walking and running today for a total of 70 minutes. I started off with Week 2 of C25K, and then just alternated walking and jogging after that.

In the end, I did just under 5 miles, and CardioTrainer had me at 501 calories burned.
My HRM said I burned 780
And MFP gave me 378 (although I knew it wouldn't be as accurate since I was both walking and running, and I didn't remember how long I did of each and at what MPH, so I averaged.)

Ok so long story short, why such a discrepancy? And which one do you think is more accurate?

AND, if you don't mind sharing... what is your average heart rate when you are walking and/or running. Thanks!!

Replies

  • MuslimFitnessInstructor
    MuslimFitnessInstructor Posts: 119
    HRM is correct it works off your heart. the cardio trainer doesnt know your height and weight or if you are in range. MFP is always off.
  • tturley
    tturley Posts: 73 Member
    Try this. It's the one I trust....

    http://www.braydenwm.com/calburn.htm
  • tturley
    tturley Posts: 73 Member
    Walking 100 to 120
    Running 140 to 180
  • dordec78
    dordec78 Posts: 11 Member
    Try this. It's the one I trust....

    http://www.braydenwm.com/calburn.htm

    That is great, thank you so much!! It was right on with what my HRM said.

    Ok, so on the plus side, it seems like I am burning more calories than I thought. On the downside, I am WAY more out of shape than I thought I was (with an average heart rate today between 160-180 while walking at 3 mph and jogging at only 4-4.5 mph) I'm hoping to see those numbers go down a bit as I get more runs in.

    Thanks everyone!
  • Azdak
    Azdak Posts: 8,281 Member
    There's no way to say since I don't know if you have your HRM set up correctly. HRMs use a general equation to estimate your maximum heart rate. Around 1 in 3 people have an actual maximum heart rate that can be as high as 20-30 beats above the calculated number.

    If you are one of those people, then your HRM assumes you are working much harder than you actually are so it displays a higher calorie estimate.

    It's important to remember that HRMs do NOT measure calories. They measure heart rate. From heart rate, they estimate calories burned. However, in order for that estimate to be accurate (or as accurate as HRMs can be), the HRM makes a number of assumptions about your max HR, fitness level, and type of activity. If any of those assumptions are not accurate, the accuracy of the calorie estimate will be affected.
  • JamesBurkes
    JamesBurkes Posts: 382 Member
    In addition, the algorithm they use (certainly mine says so) is based on "steady easy running." This is why (from a calorie burning point of view) they are hopeless for weight training. In my experience they are also not great at lower heart rates. My supposed calorie burn for brisk walking 6 miles (AV HR 120) is virtually the same as running it (av HR 155).

    Now some may say "Walking 6 miles DOES equal the same as running 6 miles! It just takes longer!" but there are a few studies that say this isn't the case. And just to push it to an extreme, to cement the point, just wearing it while on the computer (Av HR 70), had me at about 10,000 calories a day or something.

    Even with a good HRM, calorie burn is still very much a guesstimate, and its effective use limited to only a few activities.

    And the reason that website gave you the same number as the HRM is probably because it uses the same algorithm - if you put the same numbers in, you'll get the same numbers out. Doesn't mean it's right, though.
  • jaz050465
    jaz050465 Posts: 3,508 Member
    I understand that Bodymmedia fit is 95% accurate.

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