Versa 2 - VO2 Max suddenly dropped by 8 pts without explanation

[dontaquero]

Hello team. I have a Versa 2. A few days ago my Cardio VO2 Max fitness score was 56 and it had been that amount for about 6 months. However, suddenly it dropped to 48 without any explanation. This does not make sense. E.g. today I went for a 6km run at a 4'53'' pace at 159 avg bpm. Do you know why this happened? Thanks!

Moderator Edit: Clarified subject

[EdsonFitbit]

Welcome to the Fitbit Community, @dontaquero.

Thank you for the information provided.

There are some factors that can affect the Cardio Fitness Score (VO2 Max) which is determined by your resting heart rate, age, gender, weight, and other personal information. For best results, please make sure your weight is correct in your Fitbit profile. Also, wear your Fitbit Versa 2 to sleep for a better resting heart-rate estimate. Your cardio fitness score will be shown as a range unless you use connected GPS for runs. Increased exercise may help you improve your score by up to 20 percent over a period of two to three months

Whether you've followed our recommendations to track and improve your Cardio Fitness Score in this site in the menu "How do I improve my cardio fitness score?" without luck, please restart your watch by following these steps. 

If you're running with GPS, please try the following tips for the best estimate:

• Go for long runs (at least 10 minutes long) on flat terrain.
• Complete multiple runs to help improve accuracy.
• Run at a faster pace if you’re able to do so. You don’t have to run at maximum speed but higher-intensity runs provide a more accurate estimate.

Hope this helps.