Fitbit burned calories vs Arc Trainer vs Treadmill

pwgphoto

Hello all, I have a Fitbit Blaze and have been using for about 10 days at the gym to track my cardio calories burned during my weight lifting workout and cardio workouts. Before the Fitbit I would go by the numbers the various cardio machines told me and didn't log weight lifting workout.

I use the Arc Trainer every day and go 30 minutes burning at least 400-430 calories according to the machine. Now the Fitbit Blaze with heart rate monitor is telling me I am burning 290-330 calories for the same 30 minutes using the Elliptical mode under exercises since there is no Arc Trainer and the exercises are most similar. I don't mind the lower number if it is more accurate. I would think it would be because it is taking HRM measurements into account.

Now on the treadmill the machine gives me a lower number of calories burned for my 30 minutes than my Fitbit does, which I like, but I hope is also accurate.

So what do with think, just go by whatever the Fitbit says?

Thanks

LazyNightOwl

I read somewhere that gym machines use gross calories burned and that wearable fitness trackers use net calories burned. I was going to look into it more but by that point it was wayyyyy after my bedtime and I was delirious. Haven't gotten around to it (yet)... But you should read up on gross vs net Burns.

heybales

Actually - both machines and trackers report gross calories - because after all, that is the estimate of how many calories burned for that time.
Neither has an ability to know what you would have burned if you hadn't been working out. Sitting, sleeping, active, ect?

@pwgphoto - the selection of the exercise type has NO bearing on the calorie burn estimate - merely a text label so you can review your workout logs and review what you want.
You can manually go in and edit that to be specific afterwards too. "ARC at setting 6" or whatever. Also has notes if you want more details.
That's called an Activity Record. Displays what Fitbit has for stats for that chunk of time.

Compared to a Workout Record - which either syncs in from other source (MFP manually logged workout), or is manually created in Fitbit with your estimates of calorie burn or database entry calculation - that replaced the Fitbit stats when done for calories (steps for walking or running also).

HRM could be more accurate than machine, depends on if the machine knows your weight, and if it knows the watts you are generating to move against the resistance it is providing. (most machines with motors to provide resistance know this).
If it is doing this, it is NET calories because it only knows how much energy is expended by the weight given against it's known resistance - it doesn't know what you burn as base calories (RMR) being awake.
So that would actually be a comparably lower calorie burn than reality for that chunk of time.

For activity trackers and daily calorie burns - you do want GROSS for any chunk of time, not NET.
Because as soon as you enter in a Workout Record with your calorie burn figure, it replaces what Fitbit had, which includes daily burn.

HRM can be decent estimate (not for weight lifting though - only steady-state aerobic same HR for 2-4 min) if the parameters are correct, and Fitbit attempts to learn and estimate yours.

You should manually log your lifting as Weights in Fitbit for accuracy.
Start your timers so when you manually enter it you know the start and duration times, just use the Fitbit estimate of calories. It may seem low, and that's true.

lioncutie7337

This is really in-depth and helpful but could you dumb it down a little for me? I am a nurse so I get the basics of calorie burn but I am new to MFP and fitbit and want to be sure I am not over or under counting calories too much so that I don't undermine my weight loss.

heybales

Considering many Fitbit models, and 2 different methods of doing exercise calories, which then makes different workouts different accuracy potential (ya - it can't be simple) - what Fitbit model do you have, and what workouts for how much time weekly?

Your walking as a nurse are pretty good calorie burn estimates - but the fact of so much walking - either model type is going to improve accuracy if you have a manually corrected stride length - based on your average nursing walking pace.
Not walking super fast down hallway to emergency, not shuffle around a bed - those paces are on the extremes and while one is rarer than the other, you want average walking pace for the majority of your walking.
The Fitbit can figure out true pace up and down from that one.