If you are having issues with Fitness Level, please first: 

• Ensure that you are launching the Workout mode for running or walking on your watch when you go running, with the Withings App opened. If you do not launch your running session directly from the watch, your Fitness Score will not be calculated. If the Withings App is not opened, the watch will display a message asking that you open it to enable advanced tracking metrics.
• Ensure that you are running or walking outside with your mobile device, and that location services/reporting is enabled. Fitness score is only calculated when running outside with your mobile device as GPS data from your device is needed to calculate your Fitness Score. Additionally, check your Location Services (iOS) or Location Reporting (Android) and ensure that the Withings App always has access to your location data. 
• Ensure that low energy mode, power saver mode, or any other battery-saving mode is disabled as this can prevent the Withings App from accessing the GPS data from your mobile device. This option can be toggled in the settings of your Android or iOS device.
• Ensure that you run or walk for at least 10 minutes. If you do not run for at least 10 minutes, your Fitness Level cannot be calculated.

Once you are done running or walking, pause the workout session on your watch by pressing and holding the side button for 2 seconds. Scroll to stop, and press the side button again for 2 seconds.

Your run and Fitness Level items will be available in the Home section of the Withings App. When you select your run item, you will see the Fitness Level score by scrolling down to the 'Notifications' section.