This study aims to evaluate the effect of a 12-week physical training program on police officers’ physical fitness attributes. Thirty male police officers (age, 31.03 ± 3.15 years) participated in this experimental study, having carried out a 12-week physical training program (01−04/2023), 3 times/week with an average duration of 1 h/session (through circuit work, body weight exercises, and exercises with additional weight). The physical fitness evaluations were performed at three time points (weeks: 0, T0; 8, T1; 12, T2), and consisted of morphological (height, weight, waist circumference, fat and muscle mass, body mass index, and waist-to-height ratio) and fitness (push-ups; sit-ups; pull-ups; handgrip; horizontal jump; shuttle-run test; t-test; sit-reach test) evaluations. Were observed significant improvements at (i) 8 week (T1), in waist circumference, waist-to-height ratio, and all fitness tests (except in flexibility, handgrip right/left sum, and VO2max); and (ii) 12 weeks (T2), in relative fat mass, relative muscle mass, waist circumference, waist-to-height ratio, and all the fitness tests. Although 8 weeks of training allowed us to observe improvements in most of the physical fitness attributes, all of them improved significantly in the 12-week physical training program. In accordance, prolonging the duration of the training program from, 8 to 12 weeks, results in strong improvement in the physical fitness of police officers.