The aim of this work was to examine effects of 10-week high-intensity strength interval training (HIIT) program on body composition. Seven women (31.0 ± 6.0 years old, 65.7 ± 9.8 kg body weight, 23.6 ± 2.8 kg*m-2 BMI, 18.6 ± 5.8 kg body fat, 26.0 ± 3.4 kg muscle mass) completed intervention program. We performed an analyze of body composition before and after training program. We focused especially on body fat and muscle mass. Each session consisted of short term bouts (until 30 s duration) with rest in ratio 2:1. HIIT itself lasted 15-20 min three times per week (30 trainings overall). The results showed that 10-week high-intensity strength interval training have nonsignificant positive effect on decrease of body fat and significant positive effect on increase of muscle mass.