Fitbit and bmr?

CeeBeeSlim

Hello. Just purchased a Fitbit charge hr and entered my stats. Have been literally sitting since I got it for the last hour while I peruse forums on how to get the most out of it but I noticed the "calories burned" is staying around 970. Is this my bmr? Almost every online bmr calculation I've done has me about 1200?!

shadow2soul

It would be BMR, but only up to whatever time it is in the day.

Example: I get 13 calories for every 15 mins of inactivity adding up to 1248 calories in a 24 hour period. So at 12:15 am, I will have a calorie burn of 13 calories (unless of course I'm still up for whatever reason).

CeeBeeSlim

@shadow2soul - thank you. I guess I have to educate myself further. I thought bmr was a static number - not based on activity, but on height, weight, age, gender. I thought TDEE was based on activity (sedentary vs little active, etc).

luluinca

Fitbit will give you a calorie burn at around midnight. If you haven't exercised it might be close to your BMR, otherwise it might be closer to your TDEE. It also takes awhile for your fitbit to figure you out so be patient!

shadow2soul

CeeBeeSlim wrote: »

@shadow2soul - thank you. I guess I have to educate myself further. I thought bmr was a static number - not based on activity, but on height, weight, age, gender. I thought TDEE was based on activity (sedentary vs little active, etc).

It is static. But Fitbit doesn't show it as part of your calorie burn until the time has actually passed.

If I lay in bed all day, fitbit will give me 13 calories every 15 mins until midnight. My total calorie burn will be 1248 (my BMR) because I was completely in active.

If I do stuff, Fitbit adds calories onto the 13.
Example: Between 7:30 am - 7:45 am I took 57 steps. Fitbit gave me 9 calories for the steps and 13 for my BMR for a total of 22 calories burned in that 15 min time segment.

Fitbit breaks your BMR into 15 min time segments so that it can add any activity it tracks to your BMR.

Think of it like this, fitbit is adding the calories as you burn them. At 7:45 am, I haven't burned all of my BMR calories yet. I've only burned a small portion of them for the day.
For me:
no activity = 13 calories in 15 mins
Activity = 13 calories + calories for tracked activity every 15 mins

It might help you to look at your calorie burn break down on your Fitbit dashboard (website). You should see something like this on the website, breaking down your calorie burn into 15 min time segments up to whatever time it is in the day:

Merkavar

Don't look at the Fitbit calorie burns etc until you have worn it for a whole day, the first half day you wear it, it will be all estimates and missing information, see what your calories burned are in two or three days, by looking at the previous day.

CeeBeeSlim

@shadow2soul @luluinca

Aaah! Thank you for the detailed response, shadow! It makes perfect sense now. I'll be patient! Please tell me this helped you lose weight!!

I'm a data geek so I'm hoping this will take some of the guesswork away, recognizing nothing is perfect.