There a lot of sports that imply one dose of physical demand and above everything mental. For prepare your body it needs a big concentration because are sports where it depends your physical integrity in every moment.
Actually, when I am eighteen, I want to do skydiving because I like to see the world from the sky and I want to feel as a bird.
My father has done skydiving, bungee jumping, parachute, etc. and he recommends me to do skydiving because is an unique and special experience.