The purpose of this study was to evaluate the 8-week training influence according to CrossFit® concept on the healthy adults’ body composition and to determine the diversity the training outcomes by gender. This study covered 55 subjects, 18 female and 37 male. Female mean age was 28,4 ±6,5 years, mean body height 168,2 ±6,7cm and mean body weight 60,5 ±5,0kg. Among men, mean age was 25,7 ±6,8 years, mean body height 180,2 ±6,0cm, while mean body weight 81,6 ±8,2kg. To evaluate the body composition bioelectric impedance method was used, before and after beginning the training. During 8-week of CrossFit® training 5 continuous training sessions a week has been held. Two-day gap was held after every 5 days of training. Single training session lasted 60 minutes. In female group 1 kg/m2 BMI reduce was shown, while in male group there was no statistically significant changes in this parameter. It was shown that statistically significant differences were present about every analyzed parameter of the body composition (fat tissue, lean body mass), both globally and segmentally. The CrossFit® training significantly affects fat tissue reduce in two analyzed groups, both globally and segmentally. In female group more trunk fat tissue reduce was found compared to upper and lower extremities in male group.