Garmin Calorie Question...

GBR1 Posts: 97
edited September 2012 in Road general
So a quick question for you guys n girls.

I've had a Garmin 305 for a few years, worked fine till the other day when after a very very wet ride it died...

So I replaced it with a Garmin 500.

So my question is the calorie count between the two units, both have/had the same data (heart rate zones, weight, age etc etc) and the new 500 shows considerably less calories.

These two rides are different courses but not that much different.

Any thoughts, as to why these would be so different??




  • Secteur
    Secteur Posts: 1,971
    It calculates calories based on your heart rate, so was your heart rate different on the two rides?

    Alternatively, it may use a new algorhythm, or maybe your weight / zones has changed since you originally programmed your 305 (though your post suggests this isnt the case)
  • GBR1
    GBR1 Posts: 97
    Sorry, here some data for you.. As you can see massive difference. As said all data is the same between the two units!

    305 Ride

    Average HR:131bmp
    Average Speed:15.2mph

    500 Ride

    Average HR:135bpm
    Average Speed:16.7mph

  • Garmins calories calculations have always been pants. Your post doesn't say what time both rides were though which is a factor, as is elevation . Judging by the huge difference are you 100% sure you have the same basic setup e.g. weight, sex, age etc.

    When the 205/305 first came ot they generated a lot of discussions and the 'excuse' from Garmin at the time was that they couldn't use the correct calculation as someone owned the rights to it.

    Bizarre excuse if ever I heard one - you cannot patent or copyright a calculation.
  • Think your 305 may have been massively over-estimating your calorie consumption. 4634 calories on a 53 mile ride at 15mph and an average heart-rate of 131 is pretty that speed and distance I'm burning around 1800 calories at a slightly higher heart-rate. I suspect your Edge 500 is more accurate than the 305.
  • GBR1
    GBR1 Posts: 97
    Both rides started around the same time, the 305 at 10.30ish and the 500 at 11ish...

    Altitude gained 305: 3541ft

    Altitude gained 500: 3219ft

    I agree that the 500 is prob more accurate but still don't understand the huge difference!
  • dw300
    dw300 Posts: 1,642
    For a 3.5 hour ride, at 130-140bpm .. 400-500 kcals/hr is about right. Your 305 is completely wrong.
    All the above is just advice .. you can do whatever the f*ck you wana do!
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  • DavidJB
    DavidJB Posts: 2,019
    dw300 wrote:
    For a 3.5 hour ride, at 130-140bpm .. 400-500 kcals/hr is about right. Your 305 is completely wrong.