Calories burned are incorrect - too low for some activities

[porcelina]

HI all,

I am a new member and looking for some help.

I have been tracking and logging fitness and food for many years now via sparkpeople.com. I also used to use a polar hrm for tracking calories burned when I was initially losing weight around 4-5 years ago. Neither of these had the same level of detail as the fitbit, and so I am still getting used to everything and figuring out how it all works. However, I am getting a bit perplexed!

At my goal weight (139 lbs) according to my HRM, I was burning about 400 cals on a 30 minute run and around 600 for an hours high intensity circuits class, sometimes 700 for Body Attack. Spark people would give a lower cal burn because it was more of an estimation than an accurate reading. 

I have been using my fitbit charge hr now for around a week - I have worn it for a 32 minute run, during a 45 minute Body Attack class and then for GRIT strength and CX worx this morning. Each of my burns seems a little low in my opinion: 169 for GRIT, 341 for my run, 356 for Body Attack.

The run probably makes sense to me as it was a gentle run as I am getting over a chest infection, however the gym classes don't. I don't wish to blow my own trumpet or sound conceited but I worked really hard - and always do - in GRIT and Attack. Also, a lot of my friends have fitbits and their burn was a lot higher than mine, and we were all pushing equally as hard together!

I am wondering if I have something set up wrong, or if I am using it incorrectly? The polar unfortunately is broken and it was a couple of years ago when I was using it, so it could be that over the years my body has gotten used to working at high intensity during these activities and so I don't burn as much - however I still feel just as pooped at the end of the sessions as I used to do!! Maybe I need to find some more intense workouts!

Any help would be gratefully received. Thank you.  

[tigger25]

I still have not been able to get my fitbit to correctly measure calories burned

[Tarita]

I am having the same issue. 

[ufrnd]

I am having the same issue. 

The calorie calculation is way off...low!  And, the HR monitor does not seem to be calculating continuously.  During a workout it is not uncommon for my fitbitHR to read 30-40 beats low.  

I have worn it all over my arm.  My settings are correct, and I start the workout timer when I begin workouts.  Please help!!

[TarinFitbit]

Hi guys @ufrnd, @porcelina, @Tarita, @tigger25! Have you tried to restart your tracker?. Also, I recommend create a Food Plan in order to make your calories burned more accurate. 

Let me know how it goes, I'll be around for you! 

[ufrnd]

Yes. I have done both.

I like the Fitbit and most of its features, but I'm not sure what to think if it will not gauge calories correctly.

Sent from my iPhone

[TarinFitbit]

Thank you for the update @ufrnd, lets try one more thing! Let me share with you a Caloric Burn Guidance and try to compare the information with your tracker. 

Keep me posted, I'm going to further investigate this issue! 

[ufrnd]

It read 447 which would be on far with the problem. I wear a chest strap when I workout, so I know the Fitbit is not calculating correctly.

Thank you for the help!

My best guess is that the Fitbit is not calculating HR continuously. I know that is the intent, but I do not believe it is happening. I can push the button during a workout and 8 out of 10 times the Fitbit has to adjust to catch up with correct HR...sometimes 20-30 beats off.

Again, thank you!!

Sent from my iPhone

[TarinFitbit]

It was a pleasure @ufrnd!  Please remember that Fitbit is using Pure Pulse LED lights on your tracker, this reflect onto the skin to detect blood volume changes and finely tuned algorithms are applied to measure heart rate automatically and continuously, this is different technology than other brands, so, maybe you wont have the same readings. However, let me share with you this article about Heart Rate Zones, where you can optimize your workout by targeting different training intensities and burn more calories.

Thank you very much for your findings!  

Enjoy your weekend! 

[ufrnd]

Thank you! I understand all of that, so let me give an illustration.

When I am sucking wind and my Fitbit has my HR at 110...something is off. I understand different equipment reads differently, but, so far, my Fitbit has not come close to calculating a workout correctly.

I'm not upset and I am willing to walk the road to figure this out, but I want to make sure the problem is addressed and not dismissed. This is not a case of different equipment reads differently.

Again, I'm not upset but I do want to be clear.

Again, thank you!


Sent from my iPhone

[Tarita]

Yes, I have had the same problem. I feel cheated out of my calories burned. 

[ufrnd]

Wow. Thank you for the update!


Sent from my iPhone

[Sades]

Hi, did you get a resolution/ solution to this issue? I'm experiencing the exact same thing...

[ufrnd]

I have not. A moderator was posting for a bit, but then all conversation stopped.

Sent from my iPhone

[BlackOwl]

I used to try work out with my Polar HRM (with chest band) and ChargerHR and they show different HR and different calories burnt. But not so much...something around 50-80cal for 1H of moderate activity.

But when I tried them for 24H continous wearing.... OMG there was THE DIFFERENCE!
3100cal Polar and 1900cal Charger)))) 

[BaileyYoung]

I have the SAME problem. I do a 60min HIIT workout. Have done multiple tests with heartrate monitors and it says 600 calories burned.

Fitbit Charge HR says 200 - no way this right. Hope there is a way to make this more accurate. 

[BaileyYoung]

Hi Tarin!

Hoping you can help: yes, i've created a food plan and have resrtated my tracker. any other advice?

[SebringDon]

There's a lot of information about Heart Rate issues in What should I know about my heart rate data? In particular, I'd recommend the section What Impacts the accuracy of my heart rate reading? This paragraph is particularly important concerning HIIT.

With high-intensity interval training, P90X, boxing, or other activities where your wrist is moving vigorously and non-rhythmically, the movement may prevent the sensor from finding an accurate heart rate. Similarly, with exercises such as weight lifting or rowing, your wrist muscles may flex in such a way that the band tightens and loosens during exercise.

If you have a chest strap or you're using a treadmill or other device that calculates calorie burn and you feel that's more accurate, you can always manually log your activity to get the most accurate records possible.

Hope this helps!

[BlackOwl]

I can manually log all my activities during the day. I can even count my stepson and hart beats. But why do I want to do it if I bought a device like charger HR?
It can't count because of flexes, tightens, loosens. ..even when I'm running, just running. It freezes on jogging level and that is ALL and the highest level of my activity is 135-145, even if work out was done at 80-90% of my max.

[haley4540]

I go to Orange Theory and wear a chest strap. The Fibit's calorie burn is always half. Very frustrating!