The board of education of each school district and the governing authority of each chartered nonpublic school may adopt a policy to excuse from the high school physical education requirement each student who, during high school, has participated in interscholastic athletics, marching band or cheerleading for at least two full seasons or an approved Junior Reserve Officer Training Corps (JROTC) program for two years. If the board or authority adopts such a policy, the board or authority shall not require the student to complete any Physical Education course as a condition to graduate. However, the student shall be required to complete one-half unit, consisting of at least 60 hours of instruction, in another course of study.