How accurate is the FitBit Flex??

LisaC8611

I just got a FItBit Flex bracelet and I feel like its telling me I've burned way more calories than I actually have. My daily allowance of calories has gone up because the FitBit is saying I'm burning mega calories. I'm just wondering anyone else with a FitBit has the same thing going on. Is the calories burned really accurate?

Also on a side note....I know I can wear it in the shower but should I take it off if I go in the pool?

Thanks!!

ze_hombre

I think its fairly accurate as long as you input your stats correctly. If anything I think Fitbit underestimates some things. I know my HRM says I burn a lot more on runs than Fitbit does. You can adjust the sensitivity of the device by changing the setting saying you wear it on your dominant hand (even if you don't).

I wear mine when I swim laps. Fitbit says its safe to 5 feet, so if you are going to do any diving or plan on being in the water for extended times (more than 30 minutes submerged) then I would take it off.

eaglefish

I'm thinking of getting the FB Flex for the waterproofing it offers... just swimming or kayaking for me but I don't want to toast my gps watch like I did the last time I fell out of the yak.

mlb929

I don't have the flex, I have the one, it's not accurate at all. I use it mainly to track my sleep. My running miles are always off and the calories make NO sense at all.

whisperer02

I have the flex and I think as long as you put in the correct information it is accurate. I did research on it and three other activity monitors before I bought it and the flex came out on top due to being the most accurate (I know they compared the flex, the Nike one, the Jawbone up and one more).

schnarfo

I have a flex and I think it's accurate for maintaining my weight but I find its not very good for me personally trying to lose weight which for me is fine as I'm almost at maintenance

TeaBea

I don't have the flex, I have the one, it's not accurate at all. I use it mainly to track my sleep. My running miles are always off and the calories make NO sense at all.

It's my understanding that FitBits aren't designed to accruately measure steady state cardio..... that's what HRM's specialize in. I have a FitBit One on order ... not here yet.

ze_hombre

I don't have the flex, I have the one, it's not accurate at all. I use it mainly to track my sleep. My running miles are always off and the calories make NO sense at all.

For the mileage you might need to adjust your gait settings. I did and made it much closer. Not exact, but closer.

LisaC8611

Thanks for the input. Should I not log my exercise then since the fitbit is already logging my calories burned for me?

ze_hombre

Thanks for the input. Should I not log my exercise then since the fitbit is already logging my calories burned for me?

I log anything that is intentional exercise (e.g. running, biking, etc.). MFP is smart enough to ignore step data that Fitbit logs while you are exercising as long as you are careful with the start times.

_EndGame_

Well, I read LOTS of reviews on both the Flex the the Fitbit One, and I went with the Fitbit One in the end.

After using it for a month, I discovered that even though it was more accurate than the Flex, it was still wayyyyy off with the calorie count, so I bought a HRM, and it's one of the best gadgets I've ever bought when it comes to fitness.

Check out the Polar FT4 - HRM's are the best things you can get for a dead accurate calorie burn count.

ze_hombre

Well, I read LOTS of reviews on both the Flex the the Fitbit One, and I went with the Fitbit One in the end.

After using it for a month, I discovered that even though it was more accurate than the Flex, it was still wayyyyy off with the calorie count, so I bought a HRM, and it's one of the best gadgets I've ever bought when it comes to fitness.

Check out the Polar FT4 - HRM's are the best things you can get for a dead accurate calorie burn count.

Absolutely. If you have to choose between the two the HRM is the way to go. However, HRM's are not well suited for full day tracking, whereas the Fitbits are.

FitFoodieMomBillie

Log your exercise, use a HRM if you have one for the calorie count. The fitbit is for everything else. I leave it on all day - even when I strap on the HRM... MFP and fitbit talk well to one another. I also like the option that you can allow negative numbers; when I have an all day sit-a-thon, there's nothing like seeing NEGATIVE exercise for getting you to move a bit, lol!

LisaC8611

Ok, thanks so much everyone. I was just getting confused cause it was saying I was burning more calories than I was taking in and then adjusting my calories saying I could eat more.....so many numbers! I like that the FitBit keeps track of my daily activity...I was getting frustrated when I'd log my entire workout and only get "credit" for cardio. I'm pretty new to this entire game so I'm learning as I go.

dietcokeg

I think my fitbit is accurate to a good extent but definitely not 100% it probably underestimates some times - for instance when i am doing a class like spin it doesn't count it as active minutes and i would get a minimal calorie burn as if i am just sitting at a desk - but when i do a class like step which involves a lot of movement my active minutes is spot on as its the exact duration of the class. i think its pretty accurate on the calorie burn for sleep and day to day activities for sure. i have my daily calorie burn setting to 2600 - i only reach it if im doing something like running or step.

definitely not 100% as nothing really is but i like it!

jontolson01

I log anything that is intentional exercise (e.g. running, biking, etc.). MFP is smart enough to ignore step data that Fitbit logs while you are exercising as long as you are careful with the start times.

I'm wondering if you had an example. In my case, I did a bootcamp class at noon. Fitbit flex originally counted 12 very active minutes. When I got to a computer, I logged (30 minutes circuit training). I made sure to put the start time for MFP at noon, but all the sudden, I ended up with 45 minutes very active on the Fitbit. Only 30 of those are probably real. Would you just log 15 additional for exercise (subtracting what the fitbit already picked up), or am I maybe not linking MFP and fitbit right yet?

dakitten2

I think its fairly accurate as long as you input your stats correctly. If anything I think Fitbit underestimates some things. I know my HRM says I burn a lot more on runs than Fitbit does. You can adjust the sensitivity of the device by changing the setting saying you wear it on your dominant hand (even if you don't).

I wear mine when I swim laps. Fitbit says its safe to 5 feet, so if you are going to do any diving or plan on being in the water for extended times (more than 30 minutes submerged) then I would take it off.

According to the Fitbit Flex manual: Device is water resistant, and can be submerged up to 10 meters. (which I believe is about 33 feet). I swam with mine all summer and it's still working.

LeslieN65

I have the Flex too:-) Love it! I wear it on my non-dominant wrist and it seems to be pretty close to accurate, except that it seems to measure UNDER instead of over, which is fine by me:-) rather be under-compensating than over any day of the week:-) and as for anything that I do that doesn't have "steps" I just log it manually and that takes care of that:-) probably in a couple of years, the updated models will do everything needed to be absolutely perfect!

heatherannh23

This has been driving me crazy! But I think I figured it out. It counts the calories you burn when you sleep too. Because...you do. Today I would've burned only 100ish calories so far but factoring in the 900 from sleep (amazing night of sleep for once) then it tells me 1,000 which is ridiculous otherwise.

Kas1m

I would like some help it. My left hand is non dominant but I wear a watch on it. I really want to wear Flex on my right (dominant). What setting do I have to change?

boyd4715

I got a FitBit Flex for Xmas and have stop wearing it on my wrist as I found that it was recording way more steps then I was actually doing. I determined this by comparing it to the Moves app on my phone. I now just have the FitBit Flex in my pocket and it is now more in line with the Moves app and what I would be expecting.

So I am still trying to figure when I should wear it on my wrist and when I should not -

boyd4715

When you say accurate what are you comparing it to?

When I wear it on my wrist - non-dominant - I can see it count steps when I am just typing on the computer -

Do I have a misunderstanding on what this device does and what it records?

vignak2013

So can someone give me the sequence of how and where to log? I just want to know how many calories I'm burning when I'm doing my workouts. If I work out at 5:00AM, when and where do I log my activity? If I put it in MFP first, how do I know what calories to enter? Thanks so much!!

Timshel_

I have the Force (The non-wrist burning kind) and it is a good GENERAL fitness counter. On par with anything in the price range. If you want more accurate you step up in price, buy a Polar or Garmin, and spend for the heart rate monitor. I have that setup and really found it overkill for all but working on time improvement for running.

So how accurate are the Force and Flex units? You will find tons of people that misunderstand what they track and how they calculate calories. In a nutshell, they are wrist worn pedometers. They allow you to enter metrics such as height, weight, age, etc to figure out your calories burned in a day. It tends to error a bit on the high side for base metabolism rate AND for exercise calories, so that pretty much is a wash in my book.

You will see some people talk about the units picking up typing or adding steps while sitting. Well, it is on your arm so that is always possible. I've had it add a few hundred steps, which might sound like a ton, but the reality of how it effects your caloric deficit for weight loss is marginal. For instance, I take about 1800 steps in a mile. A mile burns about 120 calories for me at a 4.0 pace. That extra 200 steps really only misrepresents about a couple dozen calories off. That is like forgetting to log one Hershey Kiss. Even if it logged an extra 1000 steps, calorie wise it doesn't amount to much.

Which is where people depart on usefulness. I personally tend to pay more attention to calories burned in the day overall and worry little about a few 100 calories here and there, least I be weighing and measuring everything in a lab. I wanna live and be healthy and not be a slave to finite numbers. But I digress.

Anyway, you can always log activities on Fitbit for more accurate calories counts. So if you tracked an hour of running, you can go to the Fitbit website, go to Logs, then go to the Activity page. There you search for your activity, then plug in the exact start time, duration and mileage if known. Fitbit overwrites the other tracked exercise without double booking it. You can manually enter calories there too if you have used a HRM in the past and better know that calorie burns.

I tie into MFP and I log my food here. Fitbit dumps over exercise calories based on my tracking on logs. I tend to pay more attention to my MFP remaining calories than looking at any of that on Fitbit as they differ. Works well enough.

One HUGE tip is to make sure you correct the stride length for both walking and running. I measured mine several times to get it right. When I started the step counts were pretty close but my mileage was WAY off. Since correcting them all is pretty good.

As for dominance, the recommendation is to have the unit on the non-dominant had and to make sure the unit is set to non-dominant in the settings. Search the Fitbit site for all kinds of info on it.

So accuracy is good and using it is helpful. Want more accurate, spend more. It is personal preference.

vignak2013

So can someone give me the sequence of how and where to log? I just want to know how many calories I'm burning when I'm doing my workouts. If I work out at 5:00AM, when and where do I log my activity? If I put it in MFP first, how do I know what calories to enter? Thanks so much!!

UpEarly

Mine undercounts my calories by 200-300 a day. I just eat more than it tells me to. The step count is pretty accurate though.

jenapologizes

It is accurate because it's calculating BMR.

TeaBea

It is accurate because it's calculating BMR.

No, not BMR ......but not TDEE either....somewhere in the middle.

Your BMR is zero activity. Your TDEE is BMR + activity + workouts.

FitBits do a decent job at tracking activity (but not workouts)....so with FitBit you get BMR + activity (ie: sedentary). Other methods can be used for workouts.....for steady state cardio HRMs are pretty good.

tonyciccione

I think it overestimates calorie burn for walking. Today I walked for 1h34 (slow pace, something around 4.5 km/h) and it told me I burned 692 calories (I logged the activity with the purpose of verifying its accuracy). Comparing with MFP of Runtastic (on the phone of my friend) it's out by at least 250 calories (which is almost 40-45%).

I didn't lose any weight in the first 2 weeks owning the Flex, because I was eating the calories it told me I could eat. So, I think the flex is kinda ok for normal days, but it gets way off when you reach certain levels of activity

mrsfyredude

I have the flex but I wear it on my ankle (if you wear socks just tuck it in there) that way it only measures when I move my FEET not my hands. Obviously if you're a fidgeter, it's going to measure some of those movements, but since I sit and type most of the day I find this better than wearing it on my wrist.

nebslp

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