Fitbit not accurate when running

[Thumm]

After losing my fitbit flex I decided to get the fitbit one since I like not having to wear it on my wrist. However, when I run it is very inaccurate and does not give me enough steps. I ran 1 mile yesterday and it only counted 0.25. Did 6 a few days ago and it counted 4. I have calculated and entered in my stride length but it still made no difference. Any suggestions?

[PureEvil]

Hello @Thumm,

Welcome to the community!

This is curious, my One works just fine for running...  Though I'm using the Surge more these days for runs since it tracks my HR.

How are you wearing it?  Do you clip it on to your shorts or slip it in your bra (your picture looks like that of a woman, I'm assuming that you are)?

Also, are you running outdoors or on a treadmill?  It may make a difference.

[Thumm]

Hi thanks for the reply! I am clipping it on my shorts. I haven't tried clipping it on my sports bra maybe that would work better? I have tried it on both the treadmill and running outdoors and is always inaccurate.

[TandemWalker]

Hi @Thumm. I think that clipping it to your shorts is in fact the best place to wear it.

If you have a few minutes to spare, I would like you to do a little test to see if the step count is accurate. If we can prove that it is (which I suspect it is), then we will know that the stride lengths are off. Why? Because distances reported by fitbit is the product of stride lenghts times your step count.

Here is the test:

1. Walk to an area where you can walk 50 steps without being interrupted.
2. Once you get there, wait 15-20 seconds or so; and click the button on your One to navigate to the step count screen, and jot down the step count.
3. Walk the 50 steps, counting them mentally.
4. At the count of 50, stop and wait another 15-20 seconds; then click the button again to look at your step count.

If the count went up by 50, give or take =/- 5%, then you know that your One is counting steps competently.

So let's tackle the stride lengths. So far, I am working on the assumption that the distances you refer to are distances reported directly by your Fitbit One tracker, as opposed to distances derived from your phone GPS tracking functionality. Is my assumption correct?

If it is, then you will need to revisit your stride length calculations and reset them. But keep in mind that no matter how careful you are in calculating your stride lengths, the end result will always be a best guess and nothing more than just that, a 'guesstimate', based on the assmption that you maintain the same stride length(s) all day long. Since we both know that this can't be, then it is an estimate; which will be reasonable as long as your documented stride lengths are in the ballpark.

Here's what I did to calculate my stride lengths. I used a marked school yard track, and walked and jogged  one mile, using the timing functionality on my one to document each event. Then I used the average of the two to set my stride lengths, for both running and walking, to the one number. It works well for me, perhaps because all my running workouts are interval-based, alternating between jogging and walking every 3 minutes. But even for those who don't do interval walk/jog workouts, I still think that an average of the two is the best solution, as this 'unit of measure' will also drive your daily routine steps.

My take. Have a nice day.

TW

[Thumm]

I have not tried to average out my steps to calculate my stride yet but i have calculated both my waddling and running stride and entered it into the settings of my one. When i walk the step count is accurate but i feel like when u run it is not counting all my steps and that's why it's saying i didn't run as far. This morning i ran 4 miles yet my fitbit said 2.5 and only have me around 5000 steps when I know it should be closer to 8000.

[Thumm]

I should proof read before I post...that should sati walking not waddling!

[Thumm]

And again i didn't proof read that post. ..

[TandemWalker]

Hi @Thumm. And these numbrers are coming straight from your Fitbit One, correct? The only app you're using is Fitbit, and you're not using your phone GPS tracking functionality, correct?

TW

[Thumm]

Yes, these numbers are from my fitbit and fitbit app. I use a gps watch to
get the correct distance

[TandemWalker]

OK, now you just told me what I suspected all along. Your assumption that the GPS-derived distance is more accurate may be wrong, depending on the territory covered and the accuracy of the GPS chipset in your watch, especially if your workout is off documented/mapped roads.

If your Fitbit One is not working properly, the only way to test it properly is to recalculate your stride lengths. Look, you have already confirmed from your earlier tests that your One is counting steps competetenly. So if the distances it reports are off by that much, it can only be one of two things: It's either that your stride lengths are completely off; or your GPS watch is lying to you.

So please go to a measured training track (school yard, indoor gym, whatever.) If you don't have one, use your car's odemeter to measure one mile or kilometer on a straigth stretch of road. Now set the GPS watch aside and walk/jog the mile using the timer functionality of your One to segment the event separately on your activity log and see what you get.

If the reported distance is what you expect, give or take 5%, then you know that your stride lengths are correctly set and that the Fitbit algorithm is accurately multiplying your step count by your stride lengths. If the distance reported is way off, divide the documented track distance (not what the One reported but what the length of the actual measured track) by the number of steps your One recorded during your test, to derive your new stride length and adjust your settings accordingly. Please make sure to save your change and force a sync (otherwise the change will not take effect.)

Now, repeat repeat the test and see what you get. My hunch is that your distance will be bang on.

Now that you know that your One is reporting both steps and distances accurately, you can then go back to that regular run of yours and see how the One compares to your GPS watch.

But I'll tell you this - GPS tracking devices can indeed be way off, especially when walking/jogging off documented mapped streets and roads. Unless your watch is equipped with a very sophisticated GPS chipset, satellite signal can frequently be lost, either because of heavy foliage overhead or when walking in a busy downtown core punctuated with highrise buildings.

Some of the more sophisticated GPS chipset will automatically take a best guess at the route you took during those signal interruptions by filling the gap, using mapped roads and streets. But if your travel was off the map, then the GPS algorithm will simply join the two points bewteen the your last GPS-location and GPS signal recovery point with a straight line; and that guess can lead to totally absurd distances. If you're using a circular-shape training track with a relatively short perimeter, odds are that your GPS watch will report a big zero on distance; because the satellites cannot track your movement on earth because of the short perimeter, so it they see you as reamaning at the same spot, even though you have have done 10 laps around the track!

I hope you carry out these tests through, which will give you a fix as to what's going on.

Cheers!

TW