Materials needed: Boxes, sticks (or lengths of string), cones (or shoes or paper plates) for markers, chairs you can climb on, 2x4 or bricks, anything else you can find around the house or yard
Build a Do-It-Yourself obstacle course. Use boxes for hurdles to jump over or to make tunnels to go through, sticks or bits of string to jump, cones or other markers to weave through, climb over chairs, balance on 2x4s or bricks. Run around trees and bushes. Can you think of anything else fun? Lay everything out in the yard, and then go!
If you have a play structure in your yard, can you include that? Go up and down, swing through the swings or go down the slide.