So we homeschool and not only are the PE requirements 20 minutes per day; but when you take the primal challenge you need about that same amount of time devoted to your preferred method of movement. Therefore, we are covered on all fronts!
My youngest son thought up this obstacle course and we do a combination of stretching, calisthenics, obstacle course, and walking. Plus we hit up the park and all of us do the jungle gym there and run to our heart's content.
In fact, I felt a little bad when my youngster was moving things in front of me when I was doing my daily walk on our concrete slab in our sideyard. He started putting all these things in my way. I said, "I'm going to fall on my face here Mr.". He said "Mom, I'm making an obstacle course!". Wow you have to appreciate innovation like that from a 6 year old.
We all do a series of galloping jumps over the buckets and then zigzagging around each. You could also use cones or whatever you have around your yard. We might get some small cones to take to the park to break up our routine. I'm pretty certain "cave kids" were jumping and running most of their day so 20 minutes of the same is a "walk in the park" :)