From wikipedia: American Ninja Warrior is a sports entertainment competition spin-off of the television series Sasuke, in which competitors try to complete a series of obstacle courses of increasing difficulty called “stages”.
This is one of those shows you stumble across when you cannot find anything else to watch. Then all of a sudden you can’t stop watching it. Then you find you are cheering along hoping someone gets through these crazy courses. American Ninja Warrior is flashy and looks a little like “Wipeout” at night. And yet it becomes apparent very quickly that the competitors are quite serious and have been training for years. It feels like a cross between Olympics and Battle of the Network Stars. Pretty amazing stuff.