The athletic theme is a theme that plays in various Mario levels, secondary to the main overworld theme. I think it plays in the levels that require more skill or require you to be quick on your feet, hence, it's like the player has to be athletic.
Pretty Plaza Panic, the Great Goal Pole, and Chain Link Charge are three examples I can think of from this game, the first two with the first athletic theme, and last one with the second.
Finding the way to the dawn. Liberate this guilty conscience and clear my name. - 3DS FC: 0447 - 5910 - 1026.-