Introduction. The research relevance is due to the need to improve the process of physical education of school teenagers by taking into account the specifics of physical performance in a wide range of available loads and the degree of puberty. The research purpose is to reveal the features of physical performance and motor fitness of schoolchildren aged 13-15 at different puberty stages (PSs), manifested in different relative power zones. Materials and methods. The study involved school teenagers aged 13-15 (n=168), assigned to the main medical group for health reasons. A complex of functional and motor tests was used to assess physical performance and motor fitness. Differences determined by Student’s t-test were considered significant at p<0.05. Results. An analysis of changes in physical performance in the maximum power zone showed that it significantly increases during puberty: when moving from PS I to V, an increase (t=3.09–13.06; ps<0.01–0.001) of all indicators used was observed. A similar situation was observed when working in the submaximal power zone. With an increase in the level of puberty, there was a general improvement in performance (t=2.81-9.14; ps<0.05-0.001). In the high power zone, differences between PSs I and V were revealed only in relation to PWC170 (t=10.29; p<0.001) and six-minute run (t=4.25; p<0.001). In the moderate power zone, the results of the Cooper test (t=7.92; p<0.001) and watt-pulse – WP (t=2.64; p<0.05) improved, the indicator of aerobic capacity decreased – coefficient b of Muller’s equation (t=5.48; p<0.001). In the maximum and submaximal power zones, there was a progressive increase in the integral performance ratings from PS I to V, while in the high and moderate power zones, the maximum level of functionality was observed at PS III. Conclusion. The results obtained give grounds to assume that in physical education lessons at school, when using extra-curricular and out-of-school forms of physical exercise, it is necessary to combine teenagers with the same indicators of biological maturity into one subgroup and, taking this into account, select means and methods for increasing physical performance, developing physical condition and parameters of various metabolic physical activities. The standards for assessing the physical performance and motor fitness of school teenagers of the same passport age should also be developed separately for the initial and final puberty stages.