Distance accuracy: fitbit or treadmill?

sweetdianachka
sweetdianachka Posts: 318 Member
in Fitness and Exercise
I just finished couch to 5k and I’m running on my treadmill trying to time myself running a 5k. C25k always starts with 5 min warm up and ends with 5 min cool down so I don’t want to count those. I started my Fitbit and restarted my treadmill after 5 min warm up. According to my treadmill I did 3.1 mi but Fitbit told me 2.9? Which should I trust?

Replies

  • Shortgirlrunning
    Shortgirlrunning Posts: 1,020 Member
    I have a Garmin not a Fitbit but my Garmin doesn’t work great with treadmill runs. I trust the treadmill distance over the watch.
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    sweetdianachka wrote: »
    I just finished couch to 5k and I’m running on my treadmill trying to time myself running a 5k. C25k always starts with 5 min warm up and ends with 5 min cool down so I don’t want to count those. I started my Fitbit and restarted my treadmill after 5 min warm up. According to my treadmill I did 3.1 mi but Fitbit told me 2.9? Which should I trust?

    You're FitBit is only estimating your mileage per your number of steps and learning your stride...treadmill.
  • NorthCascades
    NorthCascades Posts: 10,968 Member
    Treadmill.
  • Ikeeptrying2
    Ikeeptrying2 Posts: 156 Member
    Treadmill.
  • yirara
    yirara Posts: 9,941 Member
    Does this little difference really matter?
  • Nativestar56
    Nativestar56 Posts: 112 Member
    Another vote for treadmill. My fitbit is rarely accurate for distance.
  • callsitlikeiseeit
    callsitlikeiseeit Posts: 8,626 Member
    If all you're worried about is distance, I'd go by the treadmill over the fitbit
  • CaffeinatedConfectionist
    CaffeinatedConfectionist Posts: 1,046 Member
    As others have said, treadmill. My fitbit consistently underestimates distance by 18-20%.
  • Chieflrg
    Chieflrg Posts: 9,097 Member
    I don't think it really matters as long as you are consistent measuring yourself with one or the other.

    Running on a treadmill for a 5k is much different than running 5k outdoors. But as long as you are using the same method of measuring, you will see what progress is being made.
  • sweetdianachka
    sweetdianachka Posts: 318 Member
    Thanks everyone! I run outside and on the treadmill so I do want to be accurate so I know for myself. I am also planning on doing virtual runs, So yes it does matter!
  • heybales
    heybales Posts: 18,842 Member
    sweetdianachka wrote: »
    Thanks everyone! I run outside and on the treadmill so I do want to be accurate so I know for myself. I am also planning on doing virtual runs, So yes it does matter!

    If literally running whole time and that was normal pace you will be doing about - then it would be good to adjust the Fitbit setting for stride length running. Might as well for when you go outside.

    You have the Activity Record now for that 3.1 mile (going to assume that's decently accurate) workout chunk of time - it'll tell you how many steps were in there when you view stats on it.

    3.1 x 5280 = 16368 ft / reported steps taken = decimal feet per stride (like 2.6).
    Record the 2 ft (or whatever yours is)
    0.6 x 12 = 7.2 inches (or whatever your is)

    You can test again, but know you have better correction than default based on gender and height.

    Oh - if you are losing weight still, most find their stride length changes as they lose weight.
    After 10-15 lbs have another test - a mile run is usually good enough. A high school track using the mile markers (since most are metric now) would be better than treadmill though.
  • Chieflrg
    Chieflrg Posts: 9,097 Member
    sweetdianachka wrote: »
    Thanks everyone! I run outside and on the treadmill so I do want to be accurate so I know for myself. I am also planning on doing virtual runs, So yes it does matter!

    My point is if you use the exact same method it will be accurate to measure progress.

    Much like somebody counting calories burned or caloric intake. You could be off by 500 calories, but if you are always off 500 calories you will have the exact same data to make decisions.
  • nanastaci2020
    nanastaci2020 Posts: 1,072 Member
    edited July 2020
    Your Fitbit should have a stride setting, which may not be accurate. That will influence its readout of distance when it can't go by GPS. Even with an accurate running stride its imperfect because what if every 'step' is not the same? You're in pretty good shape that they were only slightly off between treadmill and fitbit.

    Note: you may ultimately find that running outside vs running on the treadmill that you run at different speeds. I started on treadmill and when I finally got outside, I was shocked to find I was running at a faster pace.
  • Jthanmyfitnesspal
    Jthanmyfitnesspal Posts: 3,522 Member
    Maybe neither. Home treadmills aren't all that accurate. (Although, I don't think the innacuracies hurt your workout much.)

    You can test the accuracy of the treadmill by measuring the length of the belt, putting a mark on it, and timing the number of revolutions in a certain amount of time at a certain speed. Or, you could buy a rolling ruler and test its distance accuracy. It's a piece of work for a small payoff.

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