I like a good physical challenge. And the world is a venue of endless possibilities. You could be hiking through the red rock and invent a game where your shoes can only touch rocks (it's called "Bounding"). You could be on a boat and decide to jump out of it at top speed ("Dive of Death" or "Entrada de la Muerte"). Or you could be atop a pyramid in Tical, Guatemala and decide to do a handstand (see video for the name for that). Get creative wherever you go and invent a physical challenge. You'll like life more.