Are Charge HR Calories Accurate?

[Robcarter10]

I previously had a Fitbit Charge without the heart rate sensor. It averaged me from about 2,700 calories on a lazy day to about 3,700 on a day I worked out or was busy. I am 6ft 285 Lbs. This always seemed fairly accurate to me based on what other online TDEE calculators estimated it would be. I also previously owned a Jawbone UP2 and the calorie burn was close to what fitbit says. Well, I just started to use a the Charge HR and the numbers seem really off. For example, yesterday I did 8,466 steps and Fitbit told me I burned 4,431 calories and spent 787 minutes in the fat burn zone, 30 minutes in the cardio zone, and two minutes in peak. All I did was house cleaning and went to walmart. I know that my heart rate it is a little faster than it should be. When I check it while moving around, I am usually between 85-105. However, I doubt that would cause me to burn that many calories.I thought that a heart rate model would be more accurate but feel like it is over estimating by about 500-800 calories. I usually eat somewhere around 3000 calories a day. So, it that number was accurate, I should not have been staying a consitent weight. Has anyone else experienced something like this?

[Ukase]

In a word, yes, I've experience a variation like yours. 

It seems to me the more active I am, the more "off" the Charge HR is. 

But, I did some checking. And even though the Charge HR's readings seemed to be off - my weight loss was varying day to day, but over time, it was only off by about 7% during my first month, where I focused only on my diet, with very little exercise. The 2nd-4th months, I began to increase my activity levels, and the readings, compared to the scale, were off by 10-15%. Overall, about 11% off. 

This could be due to me not using the "workout" mode. I let it figure out when I'm exercising. So, I guess the thing to do is, trim your caloric burn by about 10%, and see what impact that has on the scale. Go up or down in increments of 5% and see where you are at the end of a week or two. 

[A_Lurker]

Over a 5 month period (using weight loss as the ultimate deciding factor) I decided that I needed to burn 4100 calories to burn a pound off, instead of the traditional 3500 calories.  This was based on losing 50.9 lbs and the recorded deficit:  https://community.fitbit.com/t5/Be-Inspired/Calories-Burned-Charge-HR/m-p/1530354

It wasn't much different than I expected, and as I continue to lose weight I'll likely repeat it say every 3 or 4 months to see if it changes.  In that old post I was really just walking, no real attempts to do extended peroids of time.  I'm still not really big on formal exercise, but I've increased my steps and added three days a week of lifting so it will be interesting to see if it changes.

For me, it's a tool.  Now that I have a premise I decided that -1000 calories would bring me an actual weight loss of -1.6 lbs/week.  I stop eating at 2500 calories if I hit 3500 burned.  If I don't hit 3500 I eat less.  Since I made that decision ~6 weeks ago I've lost close to another 12 pounds.   If I've got my steps in later I may do a 30 day comparison with a scatter plot or something.

I picked the HR version as in the past I've had medical issues that showed up with an elevating heart rate, which I didn't know until I ended up in the hospital.  However, in the 8 months that I've been wearing it (and paying attention) my resting rate has dropped and I have to work harder for those calories burned.  Of course, the fact that I'm 80 pounds lighter makes it harder as well.  Oh, and at this point I'm roughly 5 pounds lighter than you, but 8 inches shorter. 

[emili]

I don't look at the calories in and calories out as "accurate" ever. Its guardrails to help keep me on the road to where I need to be. I know that if there is a certain difference between in and out at the end of the day, I will not lose. If its more, I lose, if its less I gain. This is how I maintain my weight..

I will say that with the HR function it is much closer to accurate than without. When I first got my HR over a year ago, I wore it and a chest strap monitor for the first week of working out to see what differences might show up. There were, but not so big that in made a difference in the grand scheme of things.

[josephz2va]

I don't utilize the In vs Out program myself since my Out is way off anyways and I can't consume 3,065 calories despite what they ask for.

.

To me, it's about how much effort you place. 

IN - You can buy either homestyle clean cooking materials or meal prepped packages from the grocery store. But putting as much effort into not eating what is bad for you is up to you. Such as going to the fast food joints that overload their meals with an entire jar of salt.

OUT - How much effort placed including walking, running, and personal training. I utilize Fitstar: Personal Training - Get Lean 30 minutes a day, plus 10 minute abs on my free time when nobody at work bothers me.

[tractorlegs]

Hi @Robcarter10! All Fitbit trackers, regardless of whether they have the PurePulse monitor or not, use BMR x Steps to determine calories burned. The only exception is in certain exercise modes, like for example bicycling, where it switches to BMR x Heart Rate. In what you're describing, there should not be such a marked difference in what your Charge and your Charge HR are reporting for calories.

Therefore, I think either the Charge HR's settings need to be double-checked or it is defective. The settings you need to check are in the app: Tap on Charge HR, scroll down to "Wrist Placement" and make sure the correct option (Dominant or Non-Dominant) is chosen. If this setting is correct, then the device is misrepresenting your steps and may be defective. 

I'm a guitar player, and my Fitbit counts steps as I'm sitting and playing my instrument! So I've learned that when I'm strumming away, remove the Fitbit from the wrist lol. This could be another possibility - that your Charge HR is counting "steps" based on another activity.

Hope these ideas help!

---

@Robcarter10 wrote:

I previously had a Fitbit Charge without the heart rate sensor. It averaged me from about 2,700 calories on a lazy day to about 3,700 on a day I worked out or was busy. I am 6ft 285 Lbs. This always seemed fairly accurate to me based on what other online TDEE calculators estimated it would be. I also previously owned a Jawbone UP2 and the calorie burn was close to what fitbit says. Well, I just started to use a the Charge HR and the numbers seem really off. For example, yesterday I did 8,466 steps and Fitbit told me I burned 4,431 calories and spent 787 minutes in the fat burn zone, 30 minutes in the cardio zone, and two minutes in peak. All I did was house cleaning and went to walmart. I know that my heart rate it is a little faster than it should be. When I check it while moving around, I am usually between 85-105. However, I doubt that would cause me to burn that many calories.I thought that a heart rate model would be more accurate but feel like it is over estimating by about 500-800 calories. I usually eat somewhere around 3000 calories a day. So, it that number was accurate, I should not have been staying a consitent weight. Has anyone else experienced something like this?

---

[A_Lurker]

@tractorlegs - I look back at when I first started wearing the tracker and a I found an early day where I did less than a 1000 steps in 20 mins but they were counted as active mins and I went into the cardio zone.  I was much heavier and out of shape.  Tonight I came home with a headache and few steps today and did 1000 in under 15 minutes and didn't hit the cardio zone and definitely not active minutes. So there could be quite a bit of difference between an HR and non-HR tracker depending on fitness level.

[tractorlegs]

Hi @A_Lurker, I agree with your assessment, however I was referring to the tie between steps and calories burned. As you probably know, heart rate and the "zones" it is in are all over the map (completely unreliable) while using a Fitbit. 

Go for a walk, and the tracker will track both steps and heart rate. Halfway through your walk, stop for a ten minute break at a park bench or something like that - then continue your walk. Then on the app, compare the graphs between your heart rate during the walk, and calories burned during the walk - and it will be easy to see that the tracker is using steps to determine calories burned. The calorie graph will mimic what you know you did with your steps - walk, sit ten minutes, walk - but the HR graph will be all over the map. 

---

@A_Lurker wrote:

@tractorlegs - I look back at when I first started wearing the tracker and a I found an early day where I did less than a 1000 steps in 20 mins but they were counted as active mins and I went into the cardio zone.  I was much heavier and out of shape.  Tonight I came home with a headache and few steps today and did 1000 in under 15 minutes and didn't hit the cardio zone and definitely not active minutes. So there could be quite a bit of difference between an HR and non-HR tracker depending on fitness level.

---

[A_Lurker]

@tractorlegs - I'm not sure that I agree.  Let's look at a portion of last week for me. 

So on Sunday, I did a weights routine, which was longer, but had shorter steps.  If the Charge HR was only looking at steps vs time there's no way you would see a higher number for the weights.  Looking at the individual charts is also interesting:

This looks almost exactly what I would expect it to look like.  Cardio warm-up (where I even jogged a little) and drops between some of the sets.  I usually try and pace between sets, but sometimes I have to just stand there and catch my breath.

The straight cardio I could push the speed (I picked this day specifically as I was very low on steps and did a couple of sets of ~20 mins.  This one above was the first.  Solid start but flagged after the  15 minute mark

This one was almost the same time, a few more steps, but they were more even and dragging.  I'ts far enough back that I'm not 100% on the times, but looks like 10 minutes of so-so effort, then an attempt to speed it up, considered stopping at 15 minutes but continued for the 20 minutes. I remember this one because I really really didn't want to do any more, but was still woefully low on calories burned as well as steps.

I'm not saying it's perfect (its not) but I wouldn't call it wildly inaccurate either.  I've checked it during exercise against my treadmill (which has hand grips to measure heart rate).  I'll let it check first on the treadmill then tap it over on the wristband.  They don't match but I don't think I've seen that much of a variance.

[GiuseppinaMaher]

All these comments are useful for me.