Fitbit says I burn less than MFP

Fitbit is monitoring your heartrate and is basing its estimate on that. MFP has no idea what your heartrate is for that exercise session, it has less data.

I've heard many here comment that the database of exercise in MFP: is high on calorie estimates. I've rarely relied on it, so I don't know first hand.

What are you doing in your workout and for how long? If you're doing a 20 minute workout vs a 2 hour workout: longer workouts have a greater room for error. What are you logging it as in MFP? That could be part of the issue. Some things have much variance. Like bike riding. You will burn a different # if its an exercise bike going casually, vs a spin bike going all out, vs a real bike riding in the real world with hills and such. So it could even be a scenario where the activity you selected in MFP is not the best one for what you're doing.

Are you comparing a manually entered workout using database entry to the Fitbit Adjustment that happens to appear in the Exercise Diary?
Or to the actual workout as shown on the Fitbit app?

Just wanting to confirm because I can't discern from your comments that you for sure know how the system works, and most don't when the see the Fitbit Adjustment line.

As to why the difference - yes to everything already said.
There's actually easier potential to have Fitbit inflated calorie burn.

GazelleLady wrote: »

I use Garmin and I notice a similar phenomenon. Garmin uses my heart rate to calculate calorie burn, but sometimes I think it underestimates my heart rate (making it underestimate my calorie burn). Once, I ran 9 miles and Garmin said I only burned 400 calories. Fitbit may be doing something similar for you. If you want to test the accuracy, you might manually check your heart rate after/during a workout and see how it compares to the Fitbit reading.

Heart rate only loosely correlates with calorie burn. Heart rate correlates with oxygen needs/consumption. The fitter you get, the fewer beats it takes to deliver the same blood volume or oxygen to the muscles. Running the same-terrain X miles at the same bodyweight requires roughly the same number of calories, no matter your heart rate, because what matters for calories is the amount of work (in the physics sense of "work"). As you get fitter, it take fewer heartbeats per minute to service the same amount of work, because there's more blood volume per heartbeat.

Distance and body weight is a better correlate of calorie burn. Heart rate monitors can deceive, for sure aren't gospel.

My Fitbit calculates more calories burned than MFP. This is another reason why I don't "eat my exercise calories" back; I know they are not accurate.

heybales wrote: »

slw37 wrote: »

My Fitbit calculates more calories burned than MFP. This is another reason why I don't "eat my exercise calories" back; I know they are not accurate.

So a device that literally sees what you do each day is not as accurate as a calculation where you picked from 4 rough activity levels and no exercise is included?

Because 1 value is higher than the other it must be the wrong value?
The lower is the correct value?
Based on......?

I don't pick from any "activity levels". I look at what MFP imports from Fitbit and compare it to what the Fitbit app shows as far as calories burned. They don't match.

I did not ask for anyone's opinion or advice, but thanks for playing.