Flex vs. MFP variations...

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MsMarlaJean
MsMarlaJean Posts: 1,741 Member
So I haven't synced the two accounts as of yet...I'm adjusting to using the Fitbit Flex..I like the wristband and the sleep functions, but I've already noticed some SIGNIFICANT variations in the calorie counts...for my elliptical workout, the Flex calories are WAY under what the actual machine says as well as what MFP calculates. However, on my walking the Flex the calorie count is much higher than MFPs calculations...

Which is right?

I can kinda accept the elliptical because my arms move differently and I usually do a reverse interval personal trainer workout on the ellpticals, so I'll check the Flex readings against the actual machine readings and probably go with the machines calorie count. The perplexing one for me is my walks, the Flex records them at almost DOUBLE what MFP's general calculation is...I always kinda thought I burned more than what MFP said when I walked, but not quite that much...I guess I am going to go with what Flex says, but I am definitely gonna watch it when it comes to eating back any workout calories!

I don't always eat calories back, but sometimes it's nice to have the buffer, still now with these bigger differences I'm gonna keep an eagle eye on it! LOL!

Any advice or input or perspectives from those of you using them longer would be greatly appreciated!

Replies

  • kdf606
    kdf606 Posts: 9 Member
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    could it just be the difference in the way they report? Fitbit is calculating your total calorie burn for a given period of time... That means it is taking into account the calories your body burns just from being alive and breathing + the extra calories you are burning for your activity. This is why you see a calorie burn for the time you are asleep...

    MFP, on the other hand, is going to track just the extra calories from the activity, as they've already accounted for your 'breathing' /normal lifestyle calories in your calorie goal.

    To put it into calculations:
    Let's say MFP assumes you burn 2400 calories per day just by being alive and doing basic things. When you enter in an hour of walking, maybe they will add on another 300 calories for that hour. However, they already allotted you 100 calories for being alive that hour, so it really means you burned 400 calories during that hour. Fitbit, on the other hand, will just tell you that you burned 400 calories that hour.

    I know that isnt quite the double you say you are getting, but thats probably because you only count exercise walks in MFP and if you have an activity level which is greater than what you told MFP to use for calorie estimation, you are getting back more calories than just for your exercise walks. This will be especially true if you have your MFP settings at sedentary.

    Hope that helps.
  • MsMarlaJean
    MsMarlaJean Posts: 1,741 Member
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    yes that helps..thanks a bunch...I hadn't really considered that so it's definitely something to ponder! I'm glad I am set at lightly active not sedentary. Thanks again!