International Journal of Exercise Science 15(3): 1641-1660, 2022. This study investigated traditional training (TT) versus ability-based training (ABT) in custody assistant recruits. Retrospective analysis was conducted on two recruit classes who completed an 8-week academy. The TT group (18 males, 13 females) followed a physical training model where recruits completed the same exercises with the same intensity; the ABT group (17 males, 12 females) had exercises tailored towards their ability. Pre- and post-academy, recruits were assessed in: body mass; body fat percentage (BF%); resting heart rate (RHR); blood pressure (BP); waist circumference (WC); waist-to-hip ratio (WHR); grip strength; push-ups; sit-ups; YMCA step test recovery HR; 201-m run; and 2.4-km run. Independent samples t-tests evaluated between-class pre-test differences, with significance set at p ≤ 0.05. Paired samples t-tests (p ≤ 0.05) detected within-group training changes. Change scores were calculated for each variable; independent samples t-tests (p ≤ 0.05) compared change scores between groups. The TT group had lower BF%, BP, and WC; and were superior in sit-ups and the 2.4-km run before training. After academy, the TT recruits improved WHR, grip strength, recovery HR, 201-m run, and 2.4-km run, but increased diastolic BP. The ABT recruits decreased BF%, RHR, and WC, and improved push-ups, sit-ups, recovery HR, 201-m run, and the 2.4-km run. ABT recruits had greater positive changes in BF%, RHR, diastolic BP, and sit-ups. TT and ABT recruits generally experienced favorable fitness changes; the degree of positive change tended to be greater for ABT recruits for select tests. Coupled with the diastolic BP increase for TT recruits, this may provide evidence for ABT