Body composition and fat components of the human body are of great significance in modern diagnostics and assessment of a training process when compared to other benchmarks. The basic goal of this research is to evaluate the effects of circuit training on body composition changes in female population. The sample for this research consisted of 45 female test subjects of 35 years of age in average. Eight variables were applied for body composition assessment measured through a unique and advanced double frequency technology of TANITA TBF-300 A monitor electronic scales, and the BIA technique (Bio Impedance Analysis = measuring bioelectric impedance). The test subjects had taken part in a two month long program of circuit training sessions three times a week (24 training sessions in total). Based on partial differences (t-test for dependent samples) between the initial and final testing, the results have indicated that statistically significant changes have occurred in the following variables: body weight (BW), body fat percentage (FAT%), fat tissue mass (FTM), metabolic age of a body (MTA) and body mass index (BMI). Circuit training was demonstrated to be a very efficient mean of exercise with the goal of reducing body fat in women.