Your gym sets up challenges, such as the most kilometres in October or twenty workouts in a month. You find them under the middle button, at All → Challenge.
What’s running. For each challenge you see what’s being counted, until when it runs, and possibly a goal.
Joining is a choice. If you join, the other participants see your name and your score. Sometimes your gym chooses initials instead of names.
What counts. What you already do in the app: workouts, classes, kilometres, habits, territory or path days. You don’t need to fill in anything separately.
Teams. For some challenges you choose a team. The ranking then goes on the average per participant, so a small team competes fairly.
The leaderboard. How you’re doing compared with the rest. Along the way you may get alerts, for example halfway or when you reach the goal.
The result. After the end date your place is shown, possibly with points and a badge. Share your result turns it into an image.
No challenges? Your gym sets those up itself. Without a gym, there aren’t any.