Complete the following tasks to unlock the corresponding costumes. The Costumes will prevent you from getting records or winning medals.

Unlock Bear Costume:
In Championship mode win ALL the Gold Medals in the mens events then press L or R at the character selection screen to access the costume.

Unlock Penguin Costume:
In Championship mode win ALL the Gold Medals in the womans events then press L or R at the character screen to access the costume.

Unlock Robot Costume:
In Trial mode win ALL the Gold Medals in the mens and womens events then press L or R at the character screen to access the costume.