Help with calorie burn accuracy

alsaxon
alsaxon Posts: 124 Member
edited 12:03AM in Social Groups
I just got a Fitbit and wore it yesterday for the first time. Is it me, or can you not trust the calories burned during exercise? At noon, I jogged 24 flights or stairs along with a few squats and jumping jacks. It took me about 30 minutes. Fit bit calculated 268 calories burned. I did the same exact workout around 4 pm, pushing myself a little harder, it took me 20 minutes. Fitbit said I burned 131 calories. I don't see how that can be if I did the same amount of work in less time - means I was going faster and harder. Appears they are using an oversimplified formula. Yet I don't know if any device can accurately calculate this. Anyone else find this to be an issue? I do like the heart rate monitor, but I didn't need such an expensive gadget just for that.

Replies

  • NancyN795
    NancyN795 Posts: 1,134 Member
    The first, partial day with a Fitbit is always somewhat off. It actually "learns" about your typical activity over time and does some adjustment. This is even more so with one of the HR models (Charge HR, Surge, Blaze). It takes quite a few days (or longer) to figure out your resting heart rate, which affects how it computes your calorie burn during exercise.

    On the other hand, there are certain types of exercise it just can't measure accurately, even with the heart rate monitor. The calorie burn formulas that are used for that are based on studies of people doing steady state cardio exercise (i.e. running). I'm not sure the kind of workout you describe fits into that category. You might get a better estimate by entering the exercise into Fitbit's app or website manually using the proper description (although I'm not sure what the proper description is - my exercise routines are fairly basic). Someone else may have a suggestion.

    You can also look at what your heart rate was at during the two exercise sessions. That might show that although you were going faster and harder, the heart rate your Fitbit detected wasn't significantly higher. Or, it might be that you weren't getting good HR readings during part of one or both exercise sessions. (I hate it when that happens.)
  • alsaxon
    alsaxon Posts: 124 Member
    NancyN795 wrote: »
    The first, partial day with a Fitbit is always somewhat off. It actually "learns" about your typical activity over time and does some adjustment. This is even more so with one of the HR models (Charge HR, Surge, Blaze). It takes quite a few days (or longer) to figure out your resting heart rate, which affects how it computes your calorie burn during exercise.

    On the other hand, there are certain types of exercise it just can't measure accurately, even with the heart rate monitor. The calorie burn formulas that are used for that are based on studies of people doing steady state cardio exercise (i.e. running). I'm not sure the kind of workout you describe fits into that category. You might get a better estimate by entering the exercise into Fitbit's app or website manually using the proper description (although I'm not sure what the proper description is - my exercise routines are fairly basic). Someone else may have a suggestion.

    You can also look at what your heart rate was at during the two exercise sessions. That might show that although you were going faster and harder, the heart rate your Fitbit detected wasn't significantly higher. Or, it might be that you weren't getting good HR readings during part of one or both exercise sessions. (I hate it when that happens.)

    This is very helpful information. Thank you!
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