Categorizing exercises

[Imick47]

How can I choose cross country skiing as an activity 

[Baltoscott]

You have to log it manually.  The link will give you more information, but I've copied the steps for doing it from your computer below:

1. Log into your fitbit.com dashboard.
2. At the top of the page click Log > Activities.
3. Click a common activity or search for one. If the activity is not in our system, create your own by clicking the Create custom activity text that appears below the search field.
4. Enter the duration, distance (if applicable), and start time of your activity. You can enter the number of calories burned if you'd like to.
5. Click Log. Your activity will now be visible and editable in the Activity History area.

Not sure which tracker you have, but you can mark the start time and duration with your tracker  (use something like "workout" which you can start from the charge models, the Ionic, One and Surge.  Or, if you have a flex 2 or alta model look to see if an auto exercise was created -- might show up as walking or elliptical).  Later, when you get back to your computer, you enter a manual activity with the same start time and duration, and choose cross country skiing as the activity.  The new manual activity cross-country will overwrite and provide stats for that time period.