Before joining a high school sports team, most students in the U.S. have to complete a preparticipation physical evaluation (PPE). This preseason physical is intended to check that a student is healthy enough to participate in competitive sports, but a new study from the American Academy of Pediatrics found that the requirements of the physicals vary widely across states -- so students are not always screened for conditions that could lead to big problems. The study found that the District of Columbia and every state, except for Vermont, requires a PPE for student athletes, but there are no national standards for them.