The importance of the Military forces for any state is unquestionable, and the most important component of a successful soldier is excellent physical fitness and health. Numerous studies confirm the positive effects of CrossFit training on the motor and functional abilities of various members of Special units, including members of the Armed Forces. The aim of this study was to create and test the effects of the three weeks lasting CrossFit fitness on members of the Republic of Croatia Armed Forces. The study was therefore conducted on a convenient sample of N=15 subjects age 24 to 44 during the twenty days of training, with initial and final measurement of motor and functional abilities. The research assumed that there would be a significant difference between the results of the first and final testing of the same group of respondents after successful training. In addition to testing group scores, differences between individual variables were also tested and it was found that there is significant effect of the program for push-ups and abs, but not for pull-ups and running. The hypothesis was tested with a statistical procedure t-test, and the result was t(14)=4,416, p<0,01, which means that there is a statistically significant difference between the compared groups in general. In other words, a designed three-week CrossFit fitness program has proven successful and effective in improving the motor abilities, but not in functional abilities of tested soldiers.