The list includes the great Mountain McKinley hoax of 1906, during which Frederick Cook claimed he, and fellow climber Ed Barrill summitted the mountain for the first time. Also making the list was Rosie Ruiz's Boston Marathon win and Jennifer Figge's false claims of swimming across the Atlantic Ocean. Rounding out the list are Cesare Maestri's claims of climbing Cerro Torre in Patagonia and Donal Crowhurst's attempt to win a round the world sailing race back in in 1968 that ended in his own death.
To get the true gist of the stories, you'll have to read the full post, but my short summary above gives you the big picture. Is Outside missing any other big ones? What would you add to the list?