Paper presented to the Physical Education Seminar of the 8th period of the Physical Education degree course at the Federal Institute of Paraná - IFPR - Palmas Campus. The content will cover aspects that underpin Physical Education as an out-of-school activity, as well as its role in the school environment, bearing in mind that the school and Physical Education classes are considered privileged places for the search for a better quality of life. The results of the study will also be clarified and the theories of numerous authors who defend the importance of achieving good levels of health-related physical fitness will be presented. In this way, aspects relating to the components of physical fitness will be pointed out, namely aerobic endurance, muscular strength, muscular endurance, joint flexibility and body composition. We hope that this work will contribute to future research on the subject. We also believe that this is a relevant subject, given that authors have stated the need for more research in this area, both in regular schools with a single shift and in after-school programs.