Fitbit distance vs Treadmill distance

[clairer6873]

Today I've been on the treadmill, where I've done all my runs so far and I've now completed week 11! But I've been wondering the whole way through the c25k and now bridge to 10k why my Fitbit distance is so inaccurate? Today, the treadmill says I ran 8.03km, my Fitbit says 8.65km!! Its a huge difference! I'm starting and stopping my Fitbit at pretty much the same time I start (give or take a couple of seconds!)

I'm worried about the accuracy of distance using my Fitbit for when I start some outdoor runs...

Does anybody else find this? 🏃‍♀️

[backintime Graduate]

My phone has a tracking app (LG G3). And it's completely useless. Sometimes it doesn't recognise tbat I'm running and sometimes it says I did cycling...I haven't been on a bike in years.

I had heard good things about Fitbit though. Maybe you could do some benchmarking outside ? Run a distance that you know to be accurate and see what your fit bit says ?

[clairer6873 Graduate in reply to backintime]

It's weird because with Fitbit, you can tell it what exercise you're going to do, and in the case of running you can tell it whether it's a free run (outdoor) or whether it's a treadmill run. So I really don't understand how it's so inaccurate.

Good idea to try an outdoor run where I know the distance though! Thanks for that 👍🏼😊

[LeeU Graduate]

Go with the treadmill distance, the Fitbit/Garmin or whatever you choose to use won't know how far you have truly gone, it can estimate it depending on how far it thinks you have gone depending on, mainly, arm movement.

Where-as the treadmill is made with known tolerances of gears, rollers, number of revolutions, etc, from their is it really simple maths.

My Garmin is out but I always go by the treadmill for the reason above.

[clairer6873 Graduate in reply to LeeU]

Yes I always go by the treadmill distance, I just was unsure as to why the treadmill is so different, but now I see why thanks to yours and others comments, so thank you 😊

[Tasha99 Graduate]

Fitbit doesn’t know your stride length. Get yourself outside! Dreadmills suck!

[HeavyFoot Graduate in reply to Tasha99]

Yup. Wake up and smell the cow poo!

[clairer6873 Graduate in reply to Tasha99]

Ahh okay, that explains why then! Thank you. I do need to get outside, and I told myself I would once I completed the c25k. However now I've moved on to 5 to 10k, I've carried on doing it using a treadmill! I have a 5k race for life in a few weeks so I'll have no choice but to run outside then! 🏃‍♀️

[IannodaTruffe Mentor]

Your device has to be calibrated to your personal stride length, otherwise it is just guessing.

Outdoors you can use a GPS device, which is more likely to be accurate, as, especially outdoors, nobodies stride remains totally constant throughout a run.

[clairer6873 Graduate in reply to IannodaTruffe]

Any idea how to calibrate it?! I use the GPS on my Fitbit when I go for walks and when I did the parkrun a few years back, I've just not done any outdoor runs since starting the c25k 🏃‍♀️

[IannodaTruffe Mentor in reply to clairer6873]

Sorry, never used one.

[2718281 Graduate in reply to clairer6873]

Go to the advanced seeing in the Fitbit app (to right icon and then almost at the bottom), you can manually calibrate your stride (treadmill) or let Fitbit use the GPS (only works outside)

[clairer6873 Graduate in reply to 2718281]

Thank you 😊