fitbit vs mfp estimations

carolinamombo

Just got my Charge for Christmas.
The first day I used it to track my typical daily exercise it recorded my "very active minutes" correctly but came in much lower than MFP when estimating the calories burned.
The second day my fitbit showed no "active minutes" even though I did a higher intensity workout.
What gives?? Any ideas?

editorgrrl

Your Fitbit burn is your TDEE (total daily energy expenditure). The only way to test the accuracy is to trust your Fitbit for a few weeks, then reevaluate your progress.

heybales

VAM time is given if the calorie burn is 6 x your BMR as Fitbit knows it, for manually logged workouts.

Obviously the calorie burn Fitbit knows about is based on distance and time, therefore pace, and also mass.
Distance of course from steps and stride length.

So if the workout wasn't seen with many steps, and many high intensity stuff isn't step based, then not that great a distance nor calorie burn.

If not a manually created workout, the calorie burn is still about 6 x BMR, but pace must be about 4.5 mph walking, or running about 3.3 mph. Since their formula for that is proprietary, and has changed in the past, they may have done it again too.

And for a VAM minute of time, that calorie burn must be maintained for the whole minute, not average.

sympha01

carolinamombo wrote: »

Just got my Charge for Christmas.
The first day I used it to track my typical daily exercise it recorded my "very active minutes" correctly but came in much lower than MFP when estimating the calories burned.

I've been using a Fitbit (Force) for a year and this is actually normal for me. I have MFP set to "sedentary" because I want to see every drop of exercise come in as my Fitbit adjustment LOL. But I start every day in the hole and have to burn about 200 calories worth of actual moderate exercise on the Fitbit just to get MFP and Fitbit even, and if I stop moving for very long Fitbit starts falling behind again.

{Shrug}. The two sites are using different methodologies for estimating your TDEE, essentially. I suspect that MFP adds a tiny little somethin' somethin' to "sedentary" since it's actually really hard to truly be that motionless all day long.

shrinkyy

Yeah, sedentary is not completely sedentary. A PAL of 1.4 could be bed-bound and then next step up would still be sedentary but not extremely sedentary, like 1.6... an office worker getting little to no exercise. I'm assuming MFP bases its 'sedentary' on a PAL of about 1.6 which is still a bit of walking around and activity.

I have mine set on sedentary but I'm not. Like sympha01 said, I like the fitbit to adjust everything. Before I had no idea how active I was during an average day. So according to MFP, I was sedentary and worked out only a couple of times a week! When in reality, I'm burning an extra 600-800cal a day just from walking around work. It's hard for me to adjust to being told I can eat way more calories than I thought. But on the strict 1300cal I had before, I broke the rules constantly and probably ate what MFP is telling me to eat now, but felt like I was "failing" and "overeating" all the time...

Mine only shows active minutes when I do something active for a sustained period. I was at work the other day dressing people and running from room to room (aged care) and I was absolutely sweating for 2+ hours. My fitbit said no active minutes. Then the next day I went for a fairly moderate paced walk and the entire walk is active minutes. I guess if it's stop/start it doesn't seem to count it as much.

Your MFP calories burned would only be lower if you have your activity level on MFP set above sedentary I assume. Most people recommend to put MFP on sedentary, then you know any extra calories burned are all from the fitbit adjustment and from steps you're actually doing... MFP activity level would be a bit more of an estimate

That's just what I'm learning, I only just got mine for Christmas too

heybales

MFP has Sedentary at 1.25, Lightly Active at 1.4, ect.

Based on newer research showing that people that are active are more active than the 1919 study the other TDEE tables are based on.

The other huge difference - MFP is estimating daily burn with NO exercise at all accounted or expected.

The deficit and daily eating goal are ONLY for non-exercise days.

You exercise, you burn more, you take off the same deficit, you eat more.

Which is exactly what Fitbit helps with. Even if someone thinks they are sedentary and they aren't even close - Fitbit will give adjustments showing daily activity, and/or exercise, is causing them to burn more than their bad guess.

And MFP didn't have you at sedentary - you selected that, and from your work selection, not honestly. The description had nothing about exercise in it.