@Passion4PhysEd I do one every year for my staff. What we do is that staff takes pictures of their feet on their scale and send it to me weekly. I do a % lost every week. $25 buy in and a 8 week challenge. We do a $5 cash back if you are the biggest loser each week.
@GopherSport My favorite warm-up for 2nd-5th graders is to have students do a simple tabata workout with me. Kids get their heart rates up and can talk with their friends while exercising.