The purpose of a law enforcement agency's physical conditioning program is to ensure that officer's are physically capable of performing the challenges of their work under all environmental conditions, which requires the maintenance of optimum health and physical fitness. The components of a physical conditioning program should be designed to increase an officer's strength, endurance, and mobility. Principles of physical conditions include progression in the intensity and load of training, variety in the exercises performed, recovery periods, and the use of exercises specific to the tasks an officer may be required to perform on duty. The latter may include chasing, catching, controlling, and apprehending a fleeing suspect; climbing over a 15-foot-high vertical obstacle while chasing a fleeing suspect; and standing for 6 hours while wearing 35 pounds of equipment. All fitness training programs, regardless of their specific goals, should include warm-up exercises, conditioning exercises, and cool-down exercises. This chapter provides examples of such exercises. The selection of conditioning activities will depend on fitness goals, facilities, equipment, the time available, as well as other considerations. Within the parameters that exist for a given conditioning program, the key principles should be variety and balance. The program should include resistance training with calisthenics and weights; cardiovascular conditioning through such activities as running, all-terrain hiking, swimming, and bicycling; water-related conditioning activities such as water aerobics, sprint swimming, and running in water; and obstacle-course activities. The chapter provides a sample 4-week conditioning plan.