As a requirement of their instructor-level training, students must actively engage in the specific exercises of the course they are signing up for. For these lessons to be effective and for the students to pass the courses, they must be in good physical shape. In some of these courses, students may be exposed to chemical agents. It is the responsibility of students with medical issues that have to limit their participation to get medical clearance from their doctor before enrolling. Conditions such as high blood pressure, heart issues, lung issues, including bronchitis and asthma, or allergies are among those that call for such a visit.