Full Stats
From the Main Menu, quickly press Left (x2), Right (x2), Up, Down, Left, Right, Left. You should hear a sound to confirm the code. Then go to Olympic mode to access the full statistics in all events.

Gold medals
From the Main Menu, press circle, X, triangle, square.

First in all events
From the Main Menu, press triangle, square, circle, square, X.

Gold in javelin event
At the Event Selection screen, press circle, square, X (x2).

Gold in sprint event
At the Event Selection screen, press X (x3), circle, X (x3).