FitBit Accuracy vs cardio machines

theron12

I bought a Fitbit charge 2 about 2 days ago. To me it seems to be off because when I first wake up in the morning to go pee then I go lay back down it says I walked 70 steps & I kno it's not that far a walk to the bathroom. This morning I went to the gym for a 30 walk on treadmil. I'm 30 minutes the treadmil says I Burned 220 calories but the Fitbit says I burned 414 calories. Why is this?? Am I missing something?

celiah909

I've read a few other articles/reviews that say Fitbit is way over on calories. Not sure if it will get better the longer you have it though or if you can calibrate it.

ashdawg8790

I have a Garmin so I can't attest to the accuracy of the Fitbit, but I know mine took a good two weeks for it to really seem accurate... it is going to need to take a bit of time to get used to you. Don't get too wrapped up in what it's saying until after that time.

Jabbarwocky

Supposed to become more accurate after a month or so when it "gets used" to you. You can manually set the stride. And watch out for random motions becoming steps.

MommyMeggo

Im gonna C&P my fitbit story here.

My Fitbit Charge HR has betrayed me and GROSSLY over estimated my burns. Not just exercise but my basic daily living.

Ive kept a spreadsheet for 3 weeks with my ins(MFP) my outs (Fitbit) and the deficit - with projected weight loss vs actual weigh in.
Totally not understanding WTH is happening!? I leave plenty of green calories as not to eat any over estimations...

Knowing all I know, still something wasnt right.
I knew the answer was in the math.
And the only true variable is the output, since I have that kung-fu-grip control over my input. Obsessively so. (I have a food scale at my desk)

So- mildly frustrated and visualizing the flow chart I see posted once a day...
I go all over the inter-webs and calculate my TDEE... and F.F.S. its 1800 including my daily hour walks.
FitBit was giving me daily burns over 2200-2500 cals.

So I add THIS column to my sheet subtracting my "ins" from the TDEE of 1800 and low and behold...the tiniest little deficits known to man.
My measly weight loss coincides PERFECTLY with my TDEE less cals in.
SCREW THE FITBITS!
<end rant>

To be safe- just check the math.

steveko89

celiah909 wrote: »

I've read a few other articles/reviews that say Fitbit is way over on calories. Not sure if it will get better the longer you have it though or if you can calibrate it.

Likewise on the fitbit articles. The sense I get is that the band/watch-based trackers are pretty decent as a gauge for general activity but to accurately track calories during a workout you're better off getting a dedicated HR monitor. When I researched prior to purchasing one ~18 months ago the Polar H7 came pretty highly reviewed at a reasonable price. Rarely have had any issue with mine, comfortable chest strap, unit just snaps in place, connects with UA Record well and pushes calorie burn to MFP automatically if you sync everything up. Supplements my Apple watch well also connecting with the native activity app on that; morning workout gets things going and then I can work to close the rings throughout the day (standing once/hour, getting my steps in).

theron12

Thanks for the information guys!

mikelombardo078

You're fitbit knows your weight and height depending on if you set it up right. The bigger you are the more you burn so you might want to keep that in mind.

laurenebargar

Personally I have found my fitbit to be pretty darn accurate,

I havent done a spreadsheet like suggested above, however I might. But im set to lose 1.5 lbs a week, I eat about 75% of my adjustment and im losing 1.89 lbs a week as an average. So i could probably eat my whole adjustment and be losing right at 1.5lbs

Silentpadna

I've also find my Charge HR to be pretty accurate. I keep spreadsheet, I cross check between TDEE estimates minus inputs, and MFP NEAT plus exercise, and it's close enough. I've also run some numbers through Shape Sense's heart rate calculators, and found them to be close as well (of course that could mean that the Fitbit and Shape Sense use similar algorithms....).

Lost 42 pounds at this point, pretty much right on schedule. My days' inputs and outputs (and deficits) fluctuate a lot, but over time, based on the burns I get, I can't complain about its accuracy at all.

Silentpadna

@theron12 what are your stats (i.e. ht/wt/age)?

theron12

Silentpadna wrote: »

@theron12 what are your stats (i.e. ht/wt/age)?

24 years old, 5'8", 276.2

theron12

My bad I weigh 274.6!

Silentpadna

theron12 wrote: »

Silentpadna wrote: »

@theron12 what are your stats (i.e. ht/wt/age)?

24 years old, 5'8", 276.2

My (amateur) guess is that your Fitbit burn may be closer to reality than the machine. If you go to Shape Sense (http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.shtml), you can noodle around with some numbers here. You have the benefit of burning a fair amount now because of your current weight. As you lose, you will burn less for the same amount of exercise - because it takes more energy to move a larger mass. 400 calories could be very close.

janeinspain

My fitbit blaze is pretty accurate too, I lose around the amount projected based on CICO and exercise. Fitbits will be more accurate than gym machines, as they have your exact info and they get a much better reading of your heart rate.

RosieRose7673

My Fitbit is pretty accurate actually.

That being said, I had an Apple Watch before and I found it underestimated my calories burned by about 400-500 a day shockingly. I was trying to maintain my weight when I had it and I ended up losing a little less than a pound a week.

Some people burn a little bit more calories than other people due to individual differences. Not wildly different but somewhat, likely +/- 250 calories. So I can see how one device may overestimate one person's calories while being relatively accurate for another person

mkpandja

I also had suspicions that my FitBit Blaze was showing bigger numbers in compare what I actually burn. I just got it so can't say anything about long term results.

StaciMarie1974

I am a Fitbit fan. Mine is accurate (based on data of what it says I've burned, what I've eaten and my weight pattern over time) but I've heard you need to give it a few days to stabilize based on 'learning' your resting heart rate.

With that said, the 200 burned # for a 275ish pound guy for 30 minutes: seems a little low. Your size factors into how much you burn, because you spend more energy moving a 275 pound body than you would if you were moving a 175 pound body.

Rammer123

I am willing to bet you didn't change the weight on the treadmill to be adjusted for you.

Generally the equipment is based off a 150 pound person which would be significantly lower than what you're burning. Your fitbit also uses your heart rate to help figure out how much oxygen you're bringing in to determine your calories burned.

theron12

The Fitbit charge 2 also isn't waterproof so will it still "adjust" to me by me taking it off everyday for about 15 minutes while I shower