Three different experiments were designed. Experiments 1 and 2 involved 29 young officers aged 22 to 35 from a relatively small suburban police department of Richardson, Texas, 3 officers from the Texas Department of Public Safety, and 130 officers from the Dallas Police Department. The third experiment involved 31 middle-aged officers aged 36 to 55 from the Dallas Police Department. The officers, who were volunteers, were required to complete various medical and physical fitness evaluations before being allowed to participate in the exercise programs. The exercise program for the young officers in experiment 1 consisted of 20 weeks of jogging. The officers exercised 3 days a week for about 45 minutes per exercise session. The first 15 minutes of the workout were devoted to various stretching and calisthenic exercises. The remaining 30 minutes were spent walking and jogging. As training progressed, participants walked less and jogged more. In addition to following the program of experiment 1, officers in experiment 2 exercised 30 minutes in a program of weight training after warmup exercises. The middle-aged officers in experiment three trained in a program of progressive jogging similar to experiment one. Findings showed that physiological changes in the young and middle-aged runners as a result of the training resulted in improved working capacity, cardiovascular function, body composition, and muscular endurance and strength. The weight training program did not affect cardiovascular function, but significantly improved treadmill running performance, body composition, strength, and muscular endurance measures. It was concluded that future physical fitness programs for police officers should include a combination of running, strength training, and motor ability development. Tabular data are provided, along with 28 references.