The Rational Evolutionary Approach to physical fitness emphasizes two key aspects: program development and program implementation. This approach also emphasizes a generic process that can be individualized for a given agency. The program development process is defined by five major components: research, communication and planning, program definition, and program design. The final component, standard definition, consists of validation, test selection and norm definition. Validation provides data and rationale to establish that physical fitness is important for performing on the job. Test selection ensures that any physical fitness test be a valid measure of what is intended to be measured. Norm definition maintains age- and-sex-adjusted standards, whereby a 20- to 29-year-old male is expected to meet a norm cutoff associated with that age group. Program implementation addresses four major areas: program operations, program leadership, evolutionary installation, and program evaluation. Program operations defines all major elements of how officers enter into and maintain themselves through the program. Program leadership is successful when the administration is committed to the program and when there are trained fitness coordinators or instructors within the agency. Evolutionary installation involves six basic steps including mandatory fitness testing and data collection. Program evaluation includes evaluating the number of officers participating, the program's impact on health statuses, and impact on job performance.