Why would I get different calories for the same exercise?

Yeah, this doesn't look normal. Are both from just regular walking around, without starting a "workout" on the clock or anything? Did you do something else during one of those times that you would view as a workout or challenging? Like lifting heavy boxes etc.

Just to give you some idea, my steps yesterday were about 5000 and Fitbit gave me a negative adjustment of 132cal, meaning I should have eaten less than my regular goal. I don't remember what my activity level is set on, but this would give you an idea of what is a normal-sized adjustment.

thomasschmidt29 wrote: »

Thanks all, I forgot that I did do some snow shoveling which could account for some of it, but I didn't feel it was all that intensive. Honestly, if it was accurate I'd shovel someone's driveway & eat pizza everyday...

Snow shoveling is good exercise, but a heart rate monitor can easily overestimate the calories. Some factors like strain or internal pressure can drive up heart rate disproportionate to actual calorie burn.

Heart rate monitors measure heart rate, and estimate calorie burn. They give better estimates for some activities than for others, and better for some people than for others. It's useful to understand their limitations.

If heart rate correlated exactly with calorie burn, we'd burn more calories sitting still watching super scary movies vs. soothing ones. We don't.

gothchiq wrote: »

I don't like these wearable estimators. They seem wildly off when I look at people's readings. I think it gives you a better estimate logging your activity into mfp and letting it estimate based on your weight and age. It'll at least be close.

For an alternative view and why I prefer my trackers...

I ran 24 miles on Saturday.

MFP’s estimate would be roughly 4000 calories for the run.

My Garmin estimated 2450 for the portion of my day that I was running.

Because of the time and effort I spent running, I did very little else that day and ended up with a negative adjustment (-900 or so) for regular daily activity.

Mfp thinks I would burn 1600 + exercise.

So using mfp activity estimates, I’m at 5600 for the day. LOL.

Garmin says I burned 3109.

I’ve been losing exactly as expected following my Garmin. I’ll stick with that.

I love my Garmin, too.

But if I ate the calories my Garmin says I burn each day, I'd lose weight at over a pound a week, probably heading toward 2 pounds some weeks . . . something I have the good sense not to do at BMI 22-point-something.

It's not about the trackers being accurate or not accurate, really; it's about us as individuals being statistically average, or not, in the ways the trackers use as metrics for estimating calories.

Jthanmyfitnesspal wrote: »

@AnnPT77 : Garmin under-estimates your daily burn? Wowzers, it seems to significantly over-estimate mine! I have the sedentary setting in MFP, so, in theory, if I walk around at work, taking the stairs and such, I burn a bit more than that.

Yesterday, I earned 600kcals on the treadmill. Garmin added 270kcals for incidental activities. Could be true: I had 16k steps (many were on the treadmill).

One place the watch consistently screws up is in counting floors climbed. There is often a major difference in floors climbed vs. descended. This is impossible at the end of the day unless you take the elevator, which I don't! The culprit is the barometric altimeter which drifts, telling the watch that you are going up or down when actually just walking along.

Not just underestimates, but underestimates dramatically. So does MFP. But that doesn't make me critical of the device, in the abstract.

Garmin thinks I burn 1500ish (sometimes less) daily, to maybe 1900 or so (rarely). I think my highest step count in the last few months was 10,000; under 5,000 is common in Winter, and I've had days of only a couple thousand. That sounds like "sedentary" to me, or quite close. At sedentary, MFP thinks I'd maintain on around 1500 calories before exercise, which is consistent with Garmin once I consider the intentional exercise.

But 4+ years of logging data says my TDEE is somewhere in the 2100 to maybe even 2400 range (it varies seasonally). The last few months, wanting to slowly lose a few pounds, I've been eating around 1800+exercise most days, with fairly frequent days well over that (hundreds to a couple of thousand over), and losing weight ultra-slowly, according to a Libra trend line (set for long-term conservative trending). High recent point of trend was 137.6 pounds in mid-October; trend is 135.6 today. But if Garmin/MFP were right, I'd be gaining around pound a week, maybe more.

For whatever reason(s), you and I are not as statistically average as the people for whom such devices estimate calories close to correctly. Since the devices estimate calories, not measure them, and they use statistical techniques to do it, we should expect that they'll be inaccurate for some people. There's a bell curve hiding underneath the statistical averages the devices spit out. Most people are near the peak of that curve - the average - but you and I are out somewhere further toward the tails with a few other people.

I still find the device very useful and interesting.

P.S. Yes, Garmin counts stairs very inaccurately for me, too. Since I live in a weird house where all the living areas are on the 2nd floor, except my foyer/workout area and basement freezer-workbench-storage, I go up and down stairs often. (I have to, to leave the house; and all groceries and such have to go up the stairs, too.) It's probably one small source of the variation I see.