Non-matriculated students may enroll in Physical Education classes via UC Extention (Fall and Spring semesters). This is termed Concurrent Enrollment.
Concurrent Enrollment is granted by the instructor on a space available basis. If you wish to enroll it's important to attend the first class meeting. If you didn't attend the first class meeting you may try to attend the second class meeting.
For example: If the first day of classes for the semester is on a Wednesday, and you want to enroll in a TuTh class, you should plan on attending the first Thursday class. Failing that, attend the second class meeting on Tuesday.
It is also a good idea to email the instructor to express your interest in the class.