Does Challenge Hound keep adding activities when the challenge is over?
Once a challenge is completed, Challenge Hound stops adding activities to the challenge. We've run a lot of challenges and found that most participants prefer a clear cut goal to achieve. If some participants achieve that goal before others, it is more motivating for participants that have not yet achieved the goal to continue, when numbers aren't being inflated beyond the goal. To put it another way, running up the scoreboard can demotivate participants still trying to complete the challenge.
Many participants are very hungry for a new challenge! Since it is super easy to create challenges with Challenge Hound, you can just set up the next challenge and have participants join and start, once they complete.
You can adjust the challenge distance for an existing challenge, although that really has mixed results and is not ideal. "Moving the goal post" can be deflating, especially after participants put a lot of effort into completing a challenge.