Charge 3 doesn't track my treadmill routines accurately

[ARR92]

I'm sure someone has asked this question, but my search skills has yet to pull any answers up. 

Is there a way to update the completed exercise with the stats from my treadmill, I have walked 2.5 miles (not holding any bars) but my Fitbit only records 1.64 miles. I have adjusted my stride accordingly and it did improve a little bit but it's still not registering all of my workout it makes me wonder if the other data like heart rate, and calories burnt are also incorrect. Could that be possible?

Moderator edit: updated subject for clarity

[MarreFitbit · Accepted solution]

Hi there @ARR92, welcome to the Community Forums. Thanks for the details provided and for already adjusting your stride length. Nice way to go! 

While reading your post I was wondering if you're using SmartTrack to track your treadmill routine or you manually start the exercise? For more information about how SmartTrack tracks activities, please review our help article: Which activities does my Fitbit device track automatically?

As you may know, your tracker cannot detect your number of steps if your arm is not moving. If you walk with a normal arm swing on the Treadmill/Elliptical, it should count the proper number of steps and calories. Take a look at the article: How does my Fitbit device count steps? and Why does my step count differ depending on where my Fitbit device? 

Also, remember that if you are using the Treadmill exercise mode on the Charge 3 it will use the Walking Stride Length and not the Running Stride Length for calculating distance from the number of steps. This will cause the distance to be off substantially. So, if you are running on the Treadmill/Elliptical, it is better to use the Run exercise mode, assuming you have correctly set up the stride lengths for Walk and Run. However, keep in mind that it is important that your arms swing freely in order for the Charge 3 to count steps, and not held next to the body.

To properly update your stride length, track a run with GPS or measure your stride length manually. Check that you did it correctly by checking the help article: Can I change my stride length in my Fitbit account?

Let me know if you need further assistance, I'll be around.