How many runs before cardio score reassessed/updated?

[Saqib_ins]

Hi, 

Started using the tracker about 40 days ago. I wear it nearly incessantly (take it off only when showing, so basically 24/7)

Anyway, that's not strictly relevant. Just that my data collection is as good as it can be. 

On to my question -

I want to make cardio data more precise. 

So, I'm going on 10 min GPS tracker runs. Fitbit says you need several of these before the cardio fitness score readjusted to this data.

Does anyone have experience of actually doing this to train the software, and how many of these 10-min runs you did before the score changed? 

[LZeeW]

@Saqib_ins   Can you please clarify something?  Fitbit is supposed to report your cardio fitness score as a single number when you do GPS runs.  Otherwise, it reports a range.  Are you saying that your Fitbit is still reporting a range or is your single number not changing?

There's a lot of misunderstanding about what this score is.  It's an estimate of your vO2max -- the volume of oxygen your lungs can take up during exercise.  In simple terms, your heart and lungs work better as you become more fit.  You're not training the software, you're improving your heart and lungs.  You don't say how often you run.  If you don't run often, it can take more that 40 days to start to see an improvement.  I read your other post from today.  If you really want to change that cardio fitness score, you should quit smoking.

[Saqib_ins]

I'm not trying to improve my cardio score, well ultimately that's the goal. 

I know that my cardio level is much lower than what Fitbit estimated. This is from just how I feel. 

But I also have measured my vo2 max manually (my legs died next day). So, I know for a fact that Fitbit estimate is inaccurate. 

I'm trying to make it more accurate (essentially trying to lower my score because that would be the real number). 

The cardio fitness score is 42.46 on Fitbit. But my vo2 max is just above 22 approximately.

About the smoking thing, thank you. What can I say other than that you are right. Planning to quit sometime in September actually. 

[LZeeW · Accepted solution]

@Saqib_ins   I can't give you an exact answer.  It depends on how many times per week you run and if your performance is improving.  Is your pace improving?  Is your average heart rate the same for your runs or can you run longer with a slower heart rate?