This chapter discusses how to effectively employ perceived threat and efficacy to promote adaptive responses to fear appeal messages. It reviews several ways in which the Extended Parallel Process Model (EPPM) has been, and can be, used to predict and explain behavior in a variety of sport and physical activity communication contexts. The chapter starts by providing an overview of the EPPM, using concussion reporting by student-athletes to illustrate its key concepts. It discusses the emergence of concussions as an important heath issue in sport and considers how the EPPM could help inform message development to increase concussion reporting. The reviews how the EPPM has been and could be used to encourage individuals to engage in exercise behaviors. In physical activity related studies, self-efficacy is commonly used to design messages to increase individuals' efficacy level for their behavioral intention or actual behavior.