Physical education teachers shoulder the burden of trying to battle the nation-wide obesity epidemic among children as their job of keeping kids active has become much more critical with so many adolescents in desperate need of physical fitness. Teachers who instruct physical education typically design a fun and active physical activity lesson that is relevant to the required curriculum by state guidelines. Physical education instructors may vary in the way they decide to construct their particular curriculum, often depending on the age group they are in charge of. Many teachers choose to make the class a fun and exciting opportunity for students to learn the values of competition through physical activity, be it through various games, challenges, running, or other similar events and exercises. More and more however, physical education teachers are incorporating health and nutritional instruction into their daily lessons, as it is now being required in many areas. Physical education teachers vary on how they ultimately grade their students' performance in their class as it can sometimes be based on varying criteria. Some will simply evaluate their students' overall attitude and amount of participation in their class, while others may set certain physical goals and them grade accordingly. There is no denying that being a physical education teacher in today's society comes with a greater sense of urgency and importance than ever before, as in many cases, a physical education teacher may be the only guidance to health and physical activity that a child has in their life.