Calories burned per day is erroneously high (with me)

[JevRuz]

I've been very actively/studiously using various fitbit bands for the past 3 years and one thing seems to always be true: the number of calories I eat is about 40-60% of the calories I supposedly burn per day. In the past 3 years I've eaten about 1,500 to 2,500 calories per day and my calories burned per day averages around 3,500, which means I should have a pretty insane deficit in calorie intake and should be shedding pounds.

I suspect fitbit thinks I burn more calories than I do because my heart rate is generally high, even when I'm not that physically active. My reported resting heart rate is usually around 67-70 bpm but, beside maybe 10 minutes in the morning, I'm generally in the 90-100 bpm range and NEVER below 85 bpm. I'm a fairly active person but my heart rate is just high even while inactive. I'm reasoning that the fitbit algorithms factor in a higher HR relative to resting as a sign of some activity, even if the accelerometer doesn't show (my wrist) is active. So maybe the issue is me and this stupid body? Anyone have any thoughts?

[JohnnyRow]

It does factor in heart rate in calories burned even when you are not getting steps.  There are some exercises you could be doing that don't involve many steps so fitbit has to consider they might still be exercise.

I would suggest manually counting your pulse when you are at rest to compare your count to Fitbit's.  I wonder if Fitbit is just misreading your heart rate.  If you have trouble counting your own heart rate manually, you can buy an spO2 meter that fits on your finger like for a doctor visit for not too much $.  It would also measure your pulse.

Also, I suggest taking a look at the daily heart rate graph on Fitbit.com dashboard.  You must be getting lower heart rate sometimes to get the lower RHR.  See if your heart rate is going way down overnight.

[JevRuz]

The heart rate monitoring is actually pretty accurate. I periodically check it manually just to make sure. My heart rate is low as to be expected during sleep but not very low: 57-70 bpm. When I wake up it's more or less the what it determines to be resting -- 66 - 72 bmp -- for maybe 10 minutes, which is when the fitbit makes it's determination about my RHR for that day. It doesn't seem to matter that I never get that again low later in the day; i.e. it doesn't revise my RHR assessment to make it higher. I think that's the way it's designed: a RHR, which is, in a sense, a "minimum value" that can go further down but not up. 

By the way, in the first few months I owned a fitbit I didn't wear it during sleep or while waking up. Which, as you might guess, meant it showed I had a much higher resting heart rate: about 80 - 84 bmp.