Aim: To investigate the effectiveness of functional training implementation for improving the physical working capacity of high school students in physical education. Materials and Methods: The research, which was conducted in 2024-2025, involved 176 high school students aged 16, of whom the experimental (EG) and the control (CG) groups were formed. Functional training was introduced into the physical education classes of the EG, while the CG high school students studied according to the existing program. The following indices were used to assess high school students’ physical working capacity: Rufier index, Kerdo vegetative index, circulatory efficiency coefficient, Stange and Genchi tests. Results: During the research period the EG revealed a significant (p . 0.05-0.001) improvement in the Rufier index by 0.8 c. u. in boys and by 0.6 c. u. in girls, the Kerdo index – by 0.8 c. u. in boys and by 0.9 c. u. in girls, circulatory efficiency coefficient – by 175.8 c. u. in boys and 189.3 c. u. in girls, the Stange test – by 6.7 seconds in boys and 5.8 seconds in girls, the Genchi test – by 4.3 seconds in boys and 3.9 seconds in girls. At the end of the experiment, the EG high school students had all studied indicators significantly better than the CG’s. Conclusions: The results of the conducted experiment prove the effectiveness of functional training implementation in physical education of high school students to improve their physical working capacity.