All physically able students shall be required to participate in the program for a minimum of one-eighth unit during each semester they are enrolled except as otherwise provided in this paragraph. A twelfth-grade student may be excused from this requirement by the principal of the school in which the student is enrolled under one of the following circumstances:
(3) An organized and supervised athletic program which requires at least as much time of participation per week as one-eighth unit of physical education.
Students in grades nine through eleven may be excused from the physical education requirement in order to enroll in academic courses not otherwise available to the student if the board of directors of the school district in which the school is located, or the authorities in charge of the school, if the school is a nonpublic school, determine that students from the school may be permitted to be excused from the physical education requirement.
A student may be excused by the principal of the school in which the student is enrolled, in consultation with the student's counselor, for up to one semester, trimester, or the equivalent of a semester or trimester, per year if the parent or guardian of the student requests in writing that the student be excused from the physical education requirement. The student seeking to be excused from the physical education requirement must, at some time during the period for which the excuse is sought, be a participant in an organized and supervised athletic program which requires at least as much time of participation per week as one-eighth unit of physical education.
The student's parent or guardian must request the excuse in writing. The principal shall inform the superintendent that the student has been excused.