Wrong calories count

[PatasCortas]

Hi. Fitbit charge 4 overestimated my calories burning in a treadmill walk.

I walked 55 min at a near 4,5 km/hour pace, walking around 3.6 km. For me, a 56 y.o. man, 157 cm height, 66 kg weight, 100-120 BPM, Fitbit estimates 363 calories, against 162 really burned (estimated from 3 different sources: a Samsung gear, the treadmill, and an on line calculator). This is a deception because an older gear 2 or a treadmill estimates better than a new Fitbit. This has consecuences because if you estimates your disposable calories to eat from this Fitbit's estimation you'll be eating a lot more than the calories necessaries to have a caloric deficit. I can understand that it's no so easy to do an accurate estimation but do you have an idea of when this problem would be solved? So thanks, Alvaro.

[JohnnyRow]

Do your sources inc lude BMR calorie burn?

And here are 2 calculators that both say you burned 509 calories if avg heart rate was 110.

http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.shtm...

https://www.calculatorpro.com/calculator/calories-burned-by-heart-rate/

What is to say your sources are more accurate than these?

One might suppose the one that knows most about you is the more accurate.

[PatasCortas]

Well, I have three sources not one saying this. You can check one of them in the next site. My BMR is near 1400 cal/day, more on less 40 cal/hour. 

The situation is this:

3 sources (gear, calculator,treadmill) : 160 cal burned + near 40 cal BMR = 200 cal burned << 509 (your estimation) or 362 (Fitbit estimation). 

What am I loosing?

https://keisan.casio.com/exec/system/1350891527

[Heybales]

It won't be solved.

HR-based calculations can be wrong for many reasons - Fitbit also uses a system that starts getting some correction after about 2 weeks, as your restingHR becomes known, and the frequency of your exercise. But even then, several best guesses are still being used (HRmax & VO2max).

But there is no denying the fact that HR-based calorie burn when near the bottom of the aerobic range will be inflated.

What to do?

Manually log your walk, using the exact same start/duration time as the existing Activity Record shows, create a new Workout Record.

Time is there, enter the distance, and allow the much more accurate distance-based calorie burn be calculated and used.

Fitbit is a replace-only system, so even though the prior Activity Record can be left for reference and seeing other stats, the calorie burn as reflected in your daily burn will indeed be replaced.

Daily burn will correctly go down.

Perhaps after a couple weeks Fitbit will be much closer. Or turn your HRM off so distance-based is used from the start.

Also, I show 200 calories too for Gross burn - which is the correct value to use in a replace-only system. You are replacing what happened in that chunk of time -  base BMR burn and exercise on top. If this was another system that kept the base burn already, and exercise was added to it - then NET would be correct usage.

https://exrx.net/Calculators/WalkRunMETs

I'd argue the treadmill may not be more accurate as some don't even ask for weight, and more recent ones clearly inflate calorie burn to look good. So if it was close that's good, but not a basis for trust.

Also - unless hooked up to a indirect calorimeter or direct system, you don't know "really burned" no matter what calculation you use.

Wrong idea on any of these systems if you think they are measuring calorie burn. Some are better estimates than others.

That exrx formula has shown itself to be pretty good.

Studies have shown that walking between 2-4 mph level, and basing calculations on formula's, is much more accurate than the 15-25% accuracy a HRM may get if properly set up.

http://www.ncbi.nlm.nih.gov/pubmed/15570150

(4.2 kJ is 1 calorie. Notice the energy expenditure on treadmill and track is almost equal.)

That test Walking was 3.2 mph level for 1 mile for 19 min, calculation was 3.4 calories higher than tested 81 cal, or 4.2% higher.
Running at 6.3 mph level for 1 mile for 9.5 min, calculation was 4.8 calories lower than tested 115 cal, or 4.2% lower.

[uscpsycho]

What the OP is saying is 100% correct. I am having the exact same problem with Fitbit awarding WAAAAAY too many calories for steps walked. And it's also erratic, for example on successive days it estimated I burned 230 extra calories by walking fewer than 500 additional steps.

The Fitbit calorie calculation for steps is so far off that I now ignore it because it is nonsensical.

I just logged in today to start a thread about this very topic and my thread was marked as spam (maybe because I linked to a couple of step calculators) so you can't see my thread. Hopefully mods will release it.

[Heybales]

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@uscpsycho wrote:

What the OP is saying is 100% correct. I am having the exact same problem with Fitbit awarding WAAAAAY too many calories for steps walked. And it's also erratic, for example on successive days it estimated I burned 230 extra calories by walking fewer than 500 additional steps.

The Fitbit calorie calculation for steps is so far off that I now ignore it because it is nonsensical.

I just logged in today to start a thread about this very topic and my thread was marked as spam (maybe because I linked to a couple of step calculators) so you can't see my thread. Hopefully mods will release it.

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Well - his complaint was about a treadmill workout specifically, not all day activity walking.

Is yours?

Your's sounds more like all day since you don't mention distance or time for a workout.

What was the total distance on each day?

Because calories per step would be silly as stride length changes depending on what you do, any calculators like that if any decency have huge footnotes on how on error prone their result is going to be and it should be for entertainment purposes only.

Calories is per distance, not steps - therefore how does the distance compare for the days?

And you are talking about days with similar step counts perhaps - but no or exact same workouts between them?

[uscpsycho]

I don't want to hijack this thread. My thread was un-marked as spam so it is visible to all. If anyone wants to see what I'm referring to the link to my thread on a similar issue is here - https://community.fitbit.com/t5/Manage-Weight/Fitbit-giving-insane-and-erratic-amount-of-calories-bu...