Burned over 5000 calories before 9pm!

[yujamie]

Hi, 

I'm not sure if my calories burned are correct. Today I've worked out for an hour (weights, no cardio), and according to my Fitbit, have walked around 5 miles. The thing is, the total calories burned is 5,328 and it's only 7pm. I've always wondered if the calories burned were accurate, but today has really made me dubious. Can anyone shed any light on this? Does this sound right or is my Fitbit not working correctly? 

In case you were wondering, I'm 25 years old, 6'5 and 255lbs.

Thanks!

[MakMak]

Hi, @yujamie! That definitely seems too high.

Fitbit uses the Mifflin-St Jeor equation to calculate BMR, from which I would guess you should be more around 2000 calories at that point. I would suggest popping into your profile information and checking that all your statistics are in there correctly, because that seems way off and that's the most likely culprit.

[JoshTruong]

@yujamie

I was wondering the exact same thing.

My workout today (Weights*) was reported at 1,196 calories, average heart rate of 121bpm, over 103 minutes. I'm also 25, 6'3" and 290lbs.

I'm assuming it takes the heart rate into account, so in theory it should be accurate, but that number seems a bit high. Most calorie burn estimates aren't based on people our size, so it's hard to compare to a reference number.

*Legs and core specifically. Back squats, front squats, romanian deadlifts, hanging leg raises, russian twists, and kettlebell swings.

[JoshTruong]

@MakMak

I don't tmean to be rude, but BMR is Basal Metabolic Rate, which only determines calories required for the body to function (at rest, with no activity). 

TDEE (Total Daily Energy Expenditure) is more relevent for this question because it factors in activity.

[MakMak]

@JoshTruong, I'm well aware of what BMR is, but it's a good place to start from when estimating how many calories are burned. If the BMR is around 2200 for the day and it's already 9pm and the only activity done in the day is weight lifting, which doesn't usually register too highly in calorie expenditure on the Fitbit, it's reasonable to assume that the total day burn up until 9pm should be around 2000 calories, as I wrote. Do you somehow think that an additional 3000 calories are burned in the day? It wasn't as if we were talking about a couple of hundred calorie discrepancy. 

[JoshTruong]

@MakMak

BMR IS a good starting point, but simply being awake can add (minor) additional calorie burn over the BMR estimate. 

I don't know @yujamie's activity level throughout the day, but we have similar stats and I'm getting similar numbers (5,399 calories burnt, 5.78 miles walked, 140 active minutes).

My BMR estimate is ~2400 calories, and fitbit has set a target TDEE of ~3,700 calories for maintenance.

I work a moderately active job (A bit slow today with only ~8,000 steps by the end of the work day) and work out later in the evening.

I'm not saying this estimate is correct (I'm also curious about the accuracy), but other activity throughout the day (in addition to his workout) factors in to the fitbit estimate. It might not be intense enough for the fitbit to register as an activity, but it does add up.

And weight lifting can vary greatly regarding energy expenditure (ex. bicep curls vs. squats/deadlifts).

[MarreFitbit]

Hello guys @JoshTruong @yujamie, hope you're doing good!  Are you both using the "Weight" shortcut on your Charge 2 trackers? 

Well, let's put an example... Most strength-training workouts burn only a modest amount of calories compared to aerobic activities. Half an hour of moderate weightlifting burns 112 calories if you weigh 155 pounds and 133 calories if you're 185 pounds. Vigorous weightlifting burns 223 calories for a 155-pound person and 266 calories for a 185-pound person. Half an hour of body-weight exercises like pushups and pullups burn 167 calories if you weigh 155 pounds and 200 calories if you weigh 185 pounds. Perform these at a more vigorous intensity and you can burn 298 calories at 155 pounds and 355 calories at 185 pounds.

How long are you doing the weighting workout? And how many times per day?

Thanks for your help @MakMak! 

[JoshTruong]

Hi @MarreFitbit,

Sorry for the delayed response.

I do use the "Weight" shortcut on my Chrage 2.

I usually activate the shortcut after a brief warm-up, before I touch any weights.

My last workout was 103 minutes, average heart rate of 121 (139 peak), with a reported 1,196 calories burnt. 

I usually workout once per day for about 60 - 90 minutes in the evening, but also work a moderately active job.

I'm 25, 6'3", and 290lbs.

[Whocaress]

I'm 160lbs and my Fitbit says I burn over 5000 calories every day but I only eat around 1700. Calories. So I wonder how am I not 105lbs or dead? I also seem to burn more calories walking than running  

[paulvan36]

for me it show i burn 5000 a day and travel  10 to 15 miles a day with 20000 steps and my heart rate is 86 rest and  run normal betwen 99 and 112 so i think it inaccurate do to heart rate if your run high like mine