Do you trust your Fitbit?

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temazur
temazur Posts: 76 Member
in Health and Weight Loss
I've been using my Fitbit for almost two years, have had it synched to MFP.

Lately I've been more active and greatly exceeding my step goal.

Fitbit adds calories in under exercise if you synch it and I've mostly ignored those and not eaten them back very often. Lately, it's been adding up to 1000 calories a day.

This can't be right. I'm afraid to eat even half of those back because there's no way walking is adding that much more to what I should be eating.

Can anyone add any insight? Is there a setting I need to tinker with?
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Replies

  • jeepinshawn
    jeepinshawn Posts: 642 Member
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    I'm assuming since you are in this forum you are not maintaining but trying to lose still. Is MFP set to sedentary? If so, I'd recommend you eta back 1/2 the calories for a few weeks and see how that affects your loss.
  • kjwasmund
    kjwasmund Posts: 23 Member
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    I bought a FitBit Charge in December and really don't think it's accurate at all. The HR is never even close when I am exercising. For example, I was Kickboxing and it said I was at 92 BPM. My heart monitor said I was at 140.
  • jeepinshawn
    jeepinshawn Posts: 642 Member
    edited March 2016
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    kjwasmund wrote: »
    I bought a FitBit Charge in December and really don't think it's accurate at all. The HR is never even close when I am exercising. For example, I was Kickboxing and it said I was at 92 BPM. My heart monitor said I was at 140.

    The HR monitoring has always been questionable, but the persons post was referring to the over all TDEE earned from steps, which most people find fairly accurate.
  • itsthehumidity
    itsthehumidity Posts: 351 Member
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    I've had a Fitbit (first the Force, and now the Surge) for years. I have learned much about them, and think I can give an informed answer to your question.

    First, understand that the Fitbit is a tool, and it has limitations like any other tool. I found that the Force (which did not have a heart rate monitor) did a decent job of estimating my calories burned. My Surge overestimates my daily calories burned by 1000-1500. For example, on March 11 I had 19,000 steps (walking), didn't lift weights, and Fitbit estimated I burned 3974 calories. I'm a 5'7 male and I weigh 160 pounds; my BMR is about 1600 calories per day. To say I burned ~2400 calories from walking that much is ludicrous. That's supposedly 125 calories per 1000 steps. No way. Probably more like 50 calories per 1k steps, which would mean I burned about 2500 calories TOTAL that day, 1500 less than what Fitbit reported.

    It's staggering how wrong it is in that regard, well outside the tolerance of +/- 10% that Fitbit says I should allow. So, I have to ignore it.

    It's great for step counting, GPS tracking a hike or whatever, showing floors climbed, and other metrics. But calories burned are just plain bad, and I blame the HR monitor. Either the HR monitor doesn't accurately capture my HR, or there's a screw-up in the function that converts heart beats to calories.

    I can look past this and determine my calories burned in other ways, but if I do decide I want a different Fitbit some day I'd probably get one without HR.
  • cerise_noir
    cerise_noir Posts: 5,468 Member
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    So far, my charge HR has been accurate. I set mfp to lose 1lb/week, have my fitbit set to sedentary (to lose 1lb/week), and my TDEE -500 has been accurate so far (losing ~1lb per week). I eat all the calorie adjustment back.

    Do you have negative adjustments enabled? Perhaps your fitbit and mfp are set up with different goals or activity levels? I used to get huge adjustments when mfp calorie goal was too low.
  • Gamliela
    Gamliela Posts: 2,468 Member
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    No, my husband threw it in the trash 3 years ago now.
  • PhilP0wer
    PhilP0wer Posts: 76 Member
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    My fitbit is only accurate with the heart rate for non contact stuff like cycling. With anything involving impact like heavy bag work or quick hand movements it's way off. I think it's just a limitation of tracking heart rate by shining a light at your skin
  • Mouse_Potato
    Mouse_Potato Posts: 1,495 Member
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    Mine seems to be pretty accurate although it has a hard time with non step-based activity. As a result, it tends to underestimate my calories burned on days I do aerial silks or pole fitness.
  • Azercord
    Azercord Posts: 573 Member
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    There might be a setting mix up in there somewhere. I'm new to the fitbit realm as I just got a Blaze but even on my heavy burn days (10 mile + run with yoga in the evening) I don't seen adjustments much above the 500 mark. I've seen a few other people complain about fitbit making outrageous adjustments but I haven't heard of a specific issue causing it.
  • hamelle2
    hamelle2 Posts: 297 Member
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    My charge HR has been accurate in step counts. I had trouble at first until I did the stride test. I also had doubts about the heart rate/calorie burns. Pushing up the band about an inch on my arm during walking workouts has helped alot. I also start/stop the timer whenever I am seriously walking as this gives me the steps, HR and calories for that time only. Pretty cool to see on the fitbit graph too. Honestly, I have found mine to be very accurate but it also doesn't give me crazy numbers that others have been seeing.
  • acheben
    acheben Posts: 476 Member
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    I've found mine to be very accurate. I got my fitbit ChargeHR after I started maintaining and I've continued successfully maintaining by eating back the calories its given me. The adjustments are going to depend a lot on your activity setting in MFP. I've seen adjustments as high as 2000 calories (running a half marathon and then walking around Disney for 10+ hours) since my activity level is set to sedentary.
  • 20yearsyounger
    20yearsyounger Posts: 1,643 Member
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    itsthehumidity wrote: »
    I've had a Fitbit (first the Force, and now the Surge) for years. I have learned much about them, and think I can give an informed answer to your question.

    First, understand that the Fitbit is a tool, and it has limitations like any other tool. I found that the Force (which did not have a heart rate monitor) did a decent job of estimating my calories burned. My Surge overestimates my daily calories burned by 1000-1500. For example, on March 11 I had 19,000 steps (walking), didn't lift weights, and Fitbit estimated I burned 3974 calories. I'm a 5'7 male and I weigh 160 pounds; my BMR is about 1600 calories per day. To say I burned ~2400 calories from walking that much is ludicrous. That's supposedly 125 calories per 1000 steps. No way. Probably more like 50 calories per 1k steps, which would mean I burned about 2500 calories TOTAL that day, 1500 less than what Fitbit reported.

    It's staggering how wrong it is in that regard, well outside the tolerance of +/- 10% that Fitbit says I should allow. So, I have to ignore it.

    It's great for step counting, GPS tracking a hike or whatever, showing floors climbed, and other metrics. But calories burned are just plain bad, and I blame the HR monitor. Either the HR monitor doesn't accurately capture my HR, or there's a screw-up in the function that converts heart beats to calories.

    I can look past this and determine my calories burned in other ways, but if I do decide I want a different Fitbit some day I'd probably get one without HR.

    I just love the challenges. Just like the situation above yesterday I mostly walked. For 21k steps I got a fitburn burn of about 3100. I also wear a Garmin and I got a total burn of about 2300 for the same activities and approximate steps. It works great for some people. I guess the key is are you losing weight or maintaining? Then trust it. If you are not, then dont.
  • veliia
    veliia Posts: 70 Member
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    I've only walked 356 steps today , according to mine wrist band i've burned 868 calories. There's no way that's possible. However once I connect it to my app it tells me my active calories are 7 which sounds more reasonable.....i have a different brand tho.
  • xtina315
    xtina315 Posts: 218 Member
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    Mine has nver been accurate. It says my hr is always around 70ish, but I have tachycardia and my normal resting hr is 130 lol
  • tracie_minus100
    tracie_minus100 Posts: 465 Member
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    I have the Blaze and I think it's accurate-ish most days. (Except the HRM, I don't trust that at all). But that being said, I have it and love it for its functions, usefulness, and motivation, not because I think the numbers it gives me are totally accurate and can be taken as such. They are just for the sake of information, taken with a grain of salt.
  • 20yearsyounger
    20yearsyounger Posts: 1,643 Member
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    veliia wrote: »
    I've only walked 356 steps today , according to mine wrist band i've burned 868 calories. There's no way that's possible. However once I connect it to my app it tells me my active calories are 7 which sounds more reasonable.....i have a different brand tho.
    what is showing on your wrist probably includes what you burn by just breathing. the active calories are probably over and above that.
  • Adiemus200
    Adiemus200 Posts: 63 Member
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    I find my charge HR fairly accurate. I have successfully lost weight eating back most of my exercise calories. If im not hungry I won't eat all my calories back, but if im having a day when I am hungry I will eat them all. I veiw it mostly as a weight loss tool, it gives me a rough idea how many calories I burn. I don't think any of these gadgets are ever 100% accurate. Also make sure you have your fit bit set up correctly. I had to change the sensitivity level on mine.
  • ForecasterJason
    ForecasterJason Posts: 2,577 Member
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    I don't really trust the calorie burn it gives me, particularly if I'm doing a lot of intentional exercise. I have looked at MET calculations for various types of exercises (especially walking), and it seems like my Fitbit overestimates my exercise intensity fairly often.
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    edited March 2016
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    How is your weight in comparison to what it should be, based on the additional deficit? Are you losing on schedule, faster or slower? That is the best way to tell assuming you have 2-3 months of data to work with. In general, if you have MFP set to sedentary and you're actually fairly active, you should expect a significant adjustment.

    Personally when I'm very accurate on my diary/food logging and eat what my Fitbit shows I burn, I maintain. If I eat less, I lose. (I'm in maintenance.) For what its worth, I have the One. I know nothing about the newer models with HR function.
    temazur wrote: »
    I've been using my Fitbit for almost two years, have had it synched to MFP.

    Lately I've been more active and greatly exceeding my step goal.

    Fitbit adds calories in under exercise if you synch it and I've mostly ignored those and not eaten them back very often. Lately, it's been adding up to 1000 calories a day.

    This can't be right. I'm afraid to eat even half of those back because there's no way walking is adding that much more to what I should be eating.

    Can anyone add any insight? Is there a setting I need to tinker with?

  • ekat120
    ekat120 Posts: 407 Member
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    I have the One (had a Flex before that) and have found it to be accurate. I was skeptical at first because the numbers seemed high, but I don't gain weight when I eat as much as it tells me to eat.

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