Am I doing something wrong with Fitbit Charge HR?

BernieMBurke

I went to the doctor on Friday and she gave me the go ahead to lose an additional 10 lbs. This would put me in the healthy BMI range (goal now 170, 5' 10", male, age=58). I currently weigh 183 as of last Friday.

But when I do my exercise, mainly fast walking and a little running, I'm coming up with burns of over 1,000 calories. I walk about 6 - 8 miles at over 4.0 MPH, but that still seems high.

My BMR is currently 1,686 and with this burn, I'm going over 3,000 calories to eat. Something doesn't seem right here. With these kind of numbers, I'm going to blow down through 170 fairly fast and my doctor doesn't really want me to go any lower. I plan on setting my goal weight range at 170 (+/- 4 lbs).

What am I doing wrong?

BernieMBurke

Also, I sit at a desk all day, so I'm marked sedentary. Still, I've been able to get over 15,000 steps in 3 of the last 4 days.

langda

Hi BernieMBurke... actually that doesn't sound too far off. A person who is 183 pounds burns about 7 calories per minute of medium intensity exercise which includes walking, biking, light aerobics, etc. and about 140 calories per mile walked regardless of the pace. so if you walk 8 miles it comes out to 1,120 calories burned. BTW.... good for you that you are able to get in 15k steps in a day with a sedentary job. I too sit behind a desk and typically get 11 - 12k each day. I do an hour on the elliptical each morning and then walk for my 45 minute lunch break otherwise I wouldn't be anywhere near that number of steps in a day.

BernieMBurke

@langda, Thank you for your quick reply. I don't want to overeat, because I am trying to get to a healthy BMI. I kind of had to talk the doctor into letting me go to 170. She was a little hesitant, but when I told her I would stop at 170, she looked at her chart and said that would be OK. My next problem will be going into maintenance. I can't imagine eating over 3,000 calories a day after (currently set to lose .5 lbs a week, so that's another 250 calories) I go into maintenance.

cocobot2013

I got the charge hr too a little over a month ago and on days where I work and workout for a little it says I burn between 2300-2800 calories! I was extremely suprised but also happy but I haven't tried to increase my calories anymore just yet to see if it's accurate (Halloween ,sister in town, thanksgiving coming) but if you do id love to know if it's pretty accurate so I wont be so nervous increasing!

brb2008

I have always been blown away by the numbers my fitbit spits out for my dailu expenditure. But given my results, its very close to correct!! Yours probably is too, but maybe dont "eat back" all of the extra calories just to leave room for any errors. I never eat back more than half of my exercise calories.

Orphia

How long have you had the Fitbit Charge HR?

If you're wearing it day and night it should get pretty accurate after a couple of weeks.

Owlfan88

brb2008 wrote: »

I have always been blown away by the numbers my fitbit spits out for my dailu expenditure. But given my results, its very close to correct!! Yours probably is too, but maybe dont "eat back" all of the extra calories just to leave room for any errors. I never eat back more than half of my exercise calories.

I thought that part of the point of the Fitbit was that it gave you an accurate number of calories used all day? I'm looking to get a Fitbit at least partly for that reason, so I will know what level I should be eating to. If all my exercise is of the sort that the Fitbit will measure reasonably, can I trust its number?

3dogsrunning

Owlfan88 wrote: »

brb2008 wrote: »

I have always been blown away by the numbers my fitbit spits out for my dailu expenditure. But given my results, its very close to correct!! Yours probably is too, but maybe dont "eat back" all of the extra calories just to leave room for any errors. I never eat back more than half of my exercise calories.

I thought that part of the point of the Fitbit was that it gave you an accurate number of calories used all day? I'm looking to get a Fitbit at least partly for that reason, so I will know what level I should be eating to. If all my exercise is of the sort that the Fitbit will measure reasonably, can I trust its number?

@Owlfan88
There is no such thing as accurate outside of a lab. All of these devices give estimates. ALL have their benefits, ALL have their weaknesses.
These numbers are meant to be a starting place. Some people find them pretty close, others, not so much. It also depends on your activity.

OP - what were you eating before to lose weight?

BernieMBurke

Orphia wrote: »

How long have you had the Fitbit Charge HR?

If you're wearing it day and night it should get pretty accurate after a couple of weeks.

I just purchased it on November 7th and the numbers just looked so high. I'm going to give it some time and see how things go.

Thanks everyone!

rosebette

I'm a bit envious. I'm 56 and only 5'1.5", 120 lbs. I did around 15,000 steps, plus a belly dancing class, and my fitbit charge gave me only 1900 calories by the end of the day! Just remember that to lose, you need to eat 500 calories below what the fitbit gives you, so around 2500 would give you .5 per week weight loss. 2000 calories you could lose a lb. a week.

vrokhfit

rosebette wrote: »

I'm a bit envious. I'm 56 and only 5'1.5", 120 lbs. I did around 15,000 steps, plus a belly dancing class, and my fitbit charge gave me only 1900 calories by the end of the day! Just remember that to lose, you need to eat 500 calories below what the fitbit gives you, so around 2500 would give you .5 per week weight loss. 2000 calories you could lose a lb. a week.

If you have FitBit set at a weight loss goal the calories it gives you will include the needed deficit.

ETA: FitBit feeds your expected calorie expenditure through to MFP which also will adjust for whatever deficit you tell MFP you want.. (eg: Fit bit says you're going to expend 3000 calories today. MFP says "Okay, but he wants to lose .5 lbs this week so we'll subtract 250 from that number) The "exercise calories" that you see are the MFP adjustment from what you set your activity level at (eg: at sedentary, MFP estimates you'll burn 2000 calories per day) to what Fitbit estimates you'll expend based on actual activity.

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BernieMBurke

I actually haven't changed my eating habit too much. I usually only weigh in once a week and that will be Sunday this week. I ate at Popeye's last night so I'm drinking lots of water today to flush out some sodium plus really restricting my salt intake today.

segacs

Give it a few weeks to adapt to your habits. And I agree with those who say it will never be 100% accurate. But it should be reasonably close.

It's important to understand what the Fitbit can and can't measure.

It can't directly measure calorie expenditure. Nothing can outside of a lab.

It can measure steps, distance, heart rate, intensity and speed of movement, and then use algorithms based on formulas and population estimates to extrapolate an estimate of your calorie burn. For most of the population, it's actually pretty darn close to accurate.

But the only way to gauge it is to eat at the calories that Fitbit gives you for a few weeks and then see if you're losing weight at your expected rate. Then adjust accordingly.

Remember that your food logging will never be 100% accurate either. Even people who weigh everything on a food scale and are super careful about the database entries they use can expect a 10-20% variance on accuracy in logging. It's normal; after all, food manufacturers have some leeway on how they label, and none of us is perfect.

Strive for consistency over accuracy. You'll be less frustrated that way.

segacs

GuitarJerry wrote: »

I'm gaining weight with my Fitbit. It's estimates seem way off. I'm sticking with it for a few weeks since I spent so much goddamn money on it. I got it about 2 weeks ago, and I've been gaining weight ever since. It's estimates are just too high, IMO.

A few things you can try:

• Switch the setting to "dominant hand" even if you're wearing it on your non-dominant hand. It could be tracking ghost steps for hand movements.
• Give it a few weeks to adjust.
• Double-check the accuracy of your food logging. Most people, despite their best efforts, underestimate the amount of calories they eat, even if using a food scale.

If it's still off after those things, then don't stress. Just figure out how much it's off by, on average, and adjust your intake accordingly. So, say you find that it's 10% off for you, just eat 10% less than what it gives you.

nxd10

That looks right to me. I've been maintaining with those levels for 3 years now and lost with it too. You just walk a lot. But . . .

Don't laugh, but do think about this. My husband and I walk together. We both have a fitbit. When we walk together, I got 75% of the steps he does. He is heavier than I am with shorter legs. So I take many fewer steps for the same distance.

He doesn't lose weight if he eats back all his exercise calories. I do.

Orphia

If you haven't already, you should join the Fitbit Users group.

http://community.myfitnesspal.com/en/group/1290-fitbit-users

Then read their FAQs. They're extremely helpful.

MeanderingMammal

But when I do my exercise, mainly fast walking and a little running, I'm coming up with burns of over 1,000 calories. I walk about 6 - 8 miles at over 4.0 MPH, but that still seems high.

You're right to be sceptical. At your weight walking should be giving you between 55 and 65 cals per mile.

It's not out of the question that it's the HR measurement that's skewing the estimation high. At a moderate pace, 4mph, your HR should be reasonably low, so not particularly well associated with calorie expenditure.

fwiw, at 165lbs it takes me 90 minutes of running to burn 1000 cals. Thats about 10 miles.

MeanderingMammal

Owlfan88 wrote: »

I thought that part of the point of the Fitbit was that it gave you an accurate number of calories used all day? I'm looking to get a Fitbit at least partly for that reason, so I will know what level I should be eating to. If all my exercise is of the sort that the Fitbit will measure reasonably, can I trust its number?

Any measure that you use will only give an estimation, the accuracy depending on what the measure is, and how that relates to lifestyle.

It'll give you an approximation of distance, assuming consistent step length and limited false positives, that it then estimates calories from; energy being related to mass and distance.

Some devices use HR to corroborate the approximation, but again that means lots of assumptions about whether HR is a meaningful indicator in the circumstances. Note that it's only valid in a very limited set of circumstances.

GetThatRunnersHigh

Got my FitBit when I started maintenance. "Gained" about 5 pounds within the first two weeks of eating the calories it gave me and thought it was way overestimating my burns, but after another two weeks the weight was gone and I realized that it was just water weight from my body getting used to eating at maintenance. Give it maybe another month or so, the more you log your food/weight the more accurate the estimations will be.

That burn sounds right for your activity level, height, and weight. For reference, I am 5'1.5", 125 pounds, have a completely sedentary job, and run 20-30 miles per week. Maintenance is ~2400 calories per day.