Gym is the first class you'll take that doesn't start inside the main school building. The gym is to the south of the school, on the right hand side just beyond the bull statue. The class is taken by Mr. Burton.
There are two types of "study" in Gym - wrestling, in which you'll learn new grapple moves, and dodgeball, which increases your slingshot accuracy.
 Gym 1
Wrestling versus Fatty. Copy the on-screen prompts to perform and learn two new fighting moves.
|,||,||, +||Grapple headbutt|
|,||,||times 3||Three-hit combo|
 Gym 2
 Gym 3
Wrestling against Fatty again. Copy the on-screen prompts to perform and learn two more fighting moves.
|,||,||, +||Knee drop|
|, ,||, ,||, , times 3||Three-hit ground combo|
 Gym 4
Dodgeball, same as the last one, except against the greasers. Use the same strategies as last time, and you should breeze through.
 Gym 5
Dodgeball again, against the jocks. You should know what to do now.