Little-known fact: Jimmy and Dwayne The Rock Johnson used to have pretty successful careers as fitness instructors.
Part 1: http://www.youtube.com/watch?v=1rVNzu7smmw&list=UU8-Th83bH_thdKZDJCrn88g
Part 2: http://www.youtube.com/watch?v=y0d24yxQRvM&list=UU8-Th83bH_thdKZDJCrn88g
