"How do I create a competition that challenges each person to walk 'the most' above their average for a set amount of days? Would this motivate the walkers that are behind? Thanks"

Hi Kathy -
You might consider creating two challenges. One for the walkers who are behind, and another for walkers who are doing well.
That way it'll level the playing field a little for both groups. In creating a competition, you can restrict walkers to certain averages from joining, and so you could create an open competition for people whose averages are between 4000 steps and 6000 steps.

Another option is to run a team challenge, that way they'll have a peer support group to encourage them.