TDEE and Fitbit Charge Hr

kindrabbit

Hi.

I am 30 days into MFP and am loving the CICO way of life. I'm thinking of getting a Fitbit Charge Hr (well, saving up for one!) because I love my gadgets and I like to have lots of information to play with.

From what I understand, the charge Hr monitors your heart rate constantly so at the end of every 24 hour period you will know (to the best of its ability) how many calories you burnt that day.

My question is: Is that calorie count the total of all the calories your body used for its basic functions plus your every day exercise plus your gym workouts all included in 1 total at the end of the day?

And if that is the case - lets say it says that I 'used' 2000 calories for the whole 24 hour period. If I were to eat 1500 calories the next day would that be the correct deficit. (MFP gives me a 500 calorie deficit for 1lb a week loss)

Is that how the information is used?

Also I know they say that calorie burn from lifting is inaccurate so how do you use the charge in those circumstances?

I'm not sure if I am getting my question across but hopefully someone who has a Charge can help me.

Thanks X

betuel75

I have the Charge HR. I dont think the calories burned in a 24hr period is based on heart rate data from the Charge HR constantly monitoring your heart rate for a 24hr period. If you press a button on it it will show you your heart rate(innacurately). If you are doing some sort of exersice you can push and hold the putton on it it will start a timer and it will track your heart rate for that period of exercise until you press and hold the button again to stop the exercise period of time. It will use your heart rate logged for that period of exercise to calculate calories burned for that period of exercise. Now the heart rate monitoring is not very accurate so dont expect accurate calories burned. Even though it has a HR on it it still is best for counting steps like the Fitbit Flex. For accurate calories burned i use a Polar Chest strap HR monitor. There a different model so get the one that you like best. I use the Polar H7 which pairs via bluetooth to my iphone6 and gives me all kinds of good data/stats on the Polar Beat app. I dont use it to track weight lifting, only cardio exercise. This is what is works good at. Dont bank too much on accuracy from a Charge HR for calories burned in a 24hr period, i wouldnt use it to calculate how many calories you can eat back.

kindrabbit

Now that's exactly what I didn't want to hear!!!

kindrabbit

I have a polar FT4 which I use to log my cardio.

So what's TDEE? and whats NEAT? How do the TDEE people know how many calories to eat? and more importantly which new toy can I obsess over?

JohnBarth

The ChargeHR does use your heart rate in its calculations for estimated calorie burn whether you're in an activity mode or not.

PAV8888

Karen there is another thread discussing these toys or you may check out DC Rainmaker's blog.

I have used the vivofit, mio fuse, schorsche rhythm, and fitbit charge and many years ago a low end polar hrm.

Fitbit has a good community especially if people you know are using one. I ended up with the charge HR because of that.

I find their app and especially their calorie and how much to eat calculations to be just shy of incomprehensible and useless. Mainly because, unlike MFP, they assume that you will continue the same "rate" of activities to the end of day, and they adjust downwards as the day goes on if you don't.

To me that's pretty useless unless you regularly plan to either have dinner or head for a run at 11:30pm.

So with Fitbit you have peaks and valleys based on activity or lack thereof, whereas MFP assumes that you will continue on your pre-determined activity level to the end of day and adds exercise as a "one off".

HAVING SAID THAT, Fitbit is not useless at all : - )

The integration between fitbit and MFP works fine and yes your HR data does play into fitbit's calculations of how many calories you've burned. I have definitely had 20,000 step days with less caloric burn than 15,000 step days during which I had pushed harder!

But, just as with any other "exercise bonus" on MFP you have to be careful what you assume and perform mental arithmetic. If it is 7pm, you've just come back from a long walk, and based on Fitbit's calories burned you are getting a 700 calorie bonus... you may want to only eat back 400-500 of them as opposed to the whole shebang!

If you are engaged in HIIT or non steady state aerobic type activity the Fitbit HRM will probably not be able to keep up and you would be better off with a strap based solution, or with a strap replacement such as the Scorsche Rhythm+ which uses a Valencell sensor, or with a wrist based HRMs from Mio, or from the Tom Tom Cardio line which use the identical Mio/Philips sensors.

PAV8888

AFAIK the Charge does take your HR into account and it is fairly accurate when it comes to steady state activities or monitoring your HR when you are standing around.

When "activity mode" is not turned on the sampling frequency is lower than when activity mode is turned on. However it is still sampling.

If my Charge HR were not able to give me a HR within 2-3 or so of what a strap or manual measurement would indicate when I was just sitting or standing around (and not engaged in vigorous activity, sweating profusely, or experiencing continuous changes to my heart rate), then I would seriously consider sending it back for replacement as it appears to be perfectly capable of doing so for the vast majority of users out there : - )

StaciMarie1974

Fitbits (all) estimate daily burn based on your # of steps and the time it takes to make them, coupled with stats like height/weight/age/gender. My understanding is the HR function allows for a more accurate reading while doing cardio. Keep in mind: HRMs are not accurate for non steady-state activity.

But yes, if you're burning 2000 a day then eating around 1500 would be the goal if you're looking to average 1 pound per week loss.

JohnBarth

I'm a big math/spreadsheet dork, and I add the calories my Fitbit Surge says I burned for a week and compare it to my total calories consumed for a week. I've only been at it for a few weeks, but it's been generally consistent. One week, it'll be 15% too high; the next week it'll be 20% too low, but if I can measure my calorie output and compare to my accurately measured calorie input and get within 20 %, I'll have a great base for predicting future results. Of course, there are about a million variables that can skew these results, but long term consistency seems to be reasonable with this device.

PAV8888

StaciMarie, not that companies never lie, but:

http://help.fitbit.com/articles/en_US/Help_article/How-does-Fitbit-know-how-many-calories-I-ve-burned

Your tracker and dashboard show an estimated number of calories burned based on your BMR (Basal Metabolic Rate), which we calculate using the height, weight, age, and gender information that you provided when you set up your Fitbit account.

If your tracker measures heart rate, the calorie burn estimate also takes heart rate into account.

Note that calorie tracking for the following day begins at midnight and incorporates the calories you burn while sleeping.