I used to be the planner/organizer for our elementary school district cross-country meet every October for many years.
My school backed onto a conservation area that had lots of hills, meadows and a wooded area.
Everyone loved our natural setting and the hills really tired the kids out.
It was a big job organizing but I had people with decades of experience helping me and it always ran like clockwork.
I used to practise with my kids and in my 30's and 40's I would usually beat them, but in my 50's the Grade 8's would "take me" most of the time.