Cardio Fitness calculation seems off

[khem00]

Hi! 

I bought my Fitbit Versa about 2 weeks ago. 

I was wondering whether you could tell me if I am doing something wrong in relation to my Cardio Fitness score. 

I'm a female. 

I am 53 kg (22% BFM) and 168cm. My BPM is 61. I am 24 years old. 

I go to gym at least 4 times a week (sometimes more). 

I am an avid runner.

And yet my Cardio Fitness score is 39. 

It was suggested to me to run outside (as opposed to on a treadmill which I usually do) - and I did today. My run was 7km in 44 minutes. 

My CF score has not improved.

I consider myself generally fit so the number does not bother me as much as it puzzles me. Is it because I have average cardio fitness compared to all females using Fitbit? Or all females of my measurements using Fitbit? Or a female average in general? 

Thanks for your answer. 

[MarioDings]

Same here.

I have an incredible VO2max of 48 what I do not deserve.

My max run was 5 km in 38 minutes. (Age 63, 71 Kg)

I do have to say that I ride an electric bike (40 KM , 4 times a week) and that may be the reason why I have this score.

It should be easy to calculate, because the Cooper test is quite accurate.

The suggestions Fitbit gives me give negative results! 

So don't bother, it's just an app that tells you wrong. I tell you: keep up the good work!