How accurate are fit bits?

I have quite a labour intensive job (commercial plumber) and if I add that in with 1 hour of exercise a day (7.5 hours of work) my fit bit will read::




It just seems a lot and I don’t feel as though I’ve burned 5000 calories as I’m only eating 2000 a day

Replies

  • hunhun57
    hunhun57 Posts: 74 Member
    Fit it’s aren’t accurate . Every person I know that has one adjust their calories.Being honest I wouldn’t go by one. I would go by your height and how active you are I have a Garmin Fitbit 2 and I know for a fact it’s not all accurate.
    It all depends on what your doing. I know some construction plumbers and they walk a lot and do burn a lot while working and carry pipe .
    And too are you working out besides job. If gym time you would definitely need to eat more healthy calories because of burning and building muscle.
    Wish you all the best . I have some great friends and great support people . Men friends that hit the gym besides work . Good luck on your journey. 😁
  • nutmegoreo
    nutmegoreo Posts: 15,532 Member
    Mine underestimated about 200/day, but it didn't have heart rate monitoring.

    How long have you been eating 2000 calories? And what's your rate of loss been? Only way to know how accurate it is for you, is by testing against your own numbers.
  • heybales
    heybales Posts: 18,842 Member
    Depends - if the Fitbit was slipping into using HR-based calorie burn because the HR was high enough - inflated calorie burn.
    If your exercise is lifting and HR-based was used - inflated.

    Daily stuff should be based on distance moved for more accuracy potential - and with that many steps - if stride length setting is off then distance is wrong - big change again.

    Have you ever done a walk 1/2 to 1 mile known distance and confirmed Fitbit saw the right distance?
    It should be at 2 mph - right in middle of potential ranges of pace you'd like have through the day, from grocery store shuffle to exercise level.
    That allows the device best chance to dynamically adjust up or down based on actual pace then.

    If no HR-based kicking in, and distance was accurate - I'd actually wager the Fitbit would be underestimated.
    Because it gives all non-step time a base burn of sleeping level - and if you are standing and working - you are burning way more than that.

    The numbers on reality method can be very good compared to a tweaked Fitbit - because your food logging could also be inaccurate by some many calories.
    So in reality eating more than 2000.

    But even with poor logging - these tools just let you hone in fast, and adjust perhaps for seasonal changes.
    So while you may be eating an inaccurate and underestimated 2000 say and Fitbit says 4000 tweaked - you know if the Fitbit drops to 3500 during winter - you probably need to drop to 1500 eating to keep the loss.
    And as approaching goal weight and need to slow the rate of loss, you know need to eat 2500 logged, whatever it may really be in reality.
  • sarko15
    sarko15 Posts: 330 Member
    Here's a depressing thing I read on the internet recently: https://amp.businessinsider.com/how-accurate-is-fitbit-calories-burned

    They found a 27% margin of error, but even then, it was the most accurate out of all the trackers they tested.
  • klrenn
    klrenn Posts: 245 Member
    Mine is very accurate. I don’t have one with HR monitoring.

    I kept 3 months of data (calories in, calories out, daily weight) and my weight loss matched what my fit bit said I was burning.

    If I’m not weighing all my food it looks like the Fitbit numbers are inflated, but it’s more that I’m not being accurate in measuring my portions and underestimating how much I’m eating.
  • heybales
    heybales Posts: 18,842 Member
    sarko15 wrote: »
    Here's a depressing thing I read on the internet recently: https://amp.businessinsider.com/how-accurate-is-fitbit-calories-burned

    They found a 27% margin of error, but even then, it was the most accurate out of all the trackers they tested.

    My problem with that study like all others I've seen - they are not using the devices as they would be in normal life as designed.

    Here's study - https://www.mdpi.com/2075-4426/7/2/3

    Now the article at least mentions ongoing improvements as it monitors your activity over the weeks wearing it.

    But the study was a strap-on and measure accuracy type study like all the others.

    And these devices improve their formula for HR-based calorie burn (for the exercise) as it hones in on resting HR, and sees how often and intensity of workouts.

    And I never see them tweak the stride length for the walking daily life type pace - so important to have distance decently accurate.

    I'm not claiming the devices will be any better, perhaps they are worse.

    But totally unknowable with a study that is done poorly.
    But the number of people that come away with a tweaked device showing much better accuracy than 27% on average - tells me the study is easily flawed merely from things I can see in it.
  • kimny72
    kimny72 Posts: 16,023 Member
    Mine has been very accurate for me, but as others have said, I don't have HR on mine.
  • cwolfman13
    cwolfman13 Posts: 41,879 Member
    mine seems to jive with my own data for the most part. I get some weird readings from time to time, but for the most part it jives pretty close with my own data.
  • dougii
    dougii Posts: 676 Member
    All of the manufacturers are very careful to state that the trackers are for "entertainment" purposes. They are not particularly accurate. Mine has HR and I've tested it against several things - measured distance, vs. Garmin running watch w/HR strap. and against HR done in the doctor's office. As to steps it is pretty darn accurate. As to HR it is very close. As to calorie burn it is a crap shoot. But then again MFP's numbers are wildly inaccurate as well and even with measuring and weighing a lot of this is still guesstimates at best. If your weight is moving in the direction you want, at the pace that you expect, keep doing whatever you are doing because it's working; adjust as needed. Good luck!
  • jeff97266
    jeff97266 Posts: 93 Member
    I think my fitbit works great. My activity is tracked, it gives me FitPoints in Weight Watchers Online, and staying on budget in WW has helped me drop 60 pounds over the last 12 months.