Minute to Win It Games are great for youth groups or inter-generational activities because they work for large groups, for all ages and abilities, and everyone is actively involved. The challenges are exciting and sometimes difficult to do, and really fun to watch.
The basic concept comes from a game show on tv called Minute To Win It, participants need to complete challenges within one minute.
The internet is filled with ideas. Check out this example
Here is a playlist off of youtube that may be a good way to introduce challenges?