Dr. Biol., Professor S.P. Levushkin^{1, 2}
PhD, Associate Professor A.I. Laptev¹
PhD, Associate Professor O.F. Zhukov²
Dr. Biol., Professor V.D. Sonkin^2
1Russian University of Sport (SCOLIPE), Moscow
²Institute of Developmental Physiology of the Russian Academy of Education, Moscow

Objective of the study was to identify the current level of working capacity of elementary school students in modern conditions.
Methods and structure of the study. The analysis includes data obtained with the participation of 798 children aged 7-11 years from eight regions of the country. All children studied in elementary school from 1st to 4th grades. The calculation of the PWC170 value and the individual value of the PDAI was carried out.
Research results and conclusions. Age-related changes in the indicators of physical performance of children of primary school age demonstrate manifestations of sexual dimorphism, which manifests itself differently for each of the indicators: in the form of different dynamics of changes–for PDAI (pulse debt accumulation index) and in the form of significant inter-sex differences at a certain period of ontogenesis–for PWC170 rel. At the same time, it can be noted that the registered values of PWC170 rel. for boys and girls aged 7-11 years are consistent with the data known from the literature for this age.
The conducted study is a fragment of a long-term health monitoring program, which is supposed to be carried out on the basis of experimental sites in the form of longitudinal observation. This may make it possible to reveal the mechanisms of age-related development of physical performance and their differences in representatives of different sexes.

Keywords: schoolchildren, physical performance, pulse debt accumulation index (PDAI), work capacity, age development.

References

1. Abrosimova L.I., Karasik V.E. [Determination of physical performance of adolescents]. Novyye issledovaniya po vozrastnoy fiziologii. Moscow: Pedagogika publ., 1977. No. 2 (9). pp. 114-117.
2. Davydov A.S., Sidorov E.P. Novaya modifikatsiya testa PWC170 [New modification of the PWC170 test]. Terapevt. 2014. No. 6. pp. 68-71.
3. Kornienko I.A., Maslova G.M., Sonkin V.D., Evseev L.G. Vozrastnyye izmeneniya nekotorykh pokazateley aerobnoy proizvoditelnosti u malchikov 7-16 let [Age-related changes in some indicators of aerobic productivity in boys 7-16 years old]. Fiziologiya cheloveka. 1978. Vol. 4. No. 1. pp. 61-67.
4. Kornienko I.A., Sonkin V.D. Energeticheskaya i fiziologicheskaya «stoimost» myshechnoy raboty detey 7-17 let [Energy and physiological "cost" of muscular work of children aged 7-17]. Fiziologiya cheloveka. 1991. Vol. 17. No. 5. pp. 130-141.
5. Korol V.M., Sonkin V.D., Ratushnaya L.I. Myshechnaya rabotosposobnost i chastota serdechnykh sokrashcheniy u podrostkov v zavisimosti ot urovnya polovogo sozrevaniya [Muscular performance and heart rate in adolescents depending on the level of puberty]. Teoriya i praktika fizicheskoy kultury. 1985. No. 8. p. 27.
6. Sonkin V.D., Tambovtseva R.V. Razvitiye myshechnoy energetiki i rabotosposobnosti v ontogeneze [Development of muscular energy and working capacity in ontogeny]. Moscow: Librokom publ., 2018. 368 p.
7. Bermejo-Cantarero A., Álvarez-Bueno C., Martínez-Vizcaino V. et al. Relationship between both cardiorespiratory and muscular fitness and health-related quality of life in children and adolescents: a systematic review and meta-analysis of observational studies. Health Qual. Life Outcomes. 2021. Apr. 21. Vol. 19 (1): 127. DOI: 10.1186/s12955-021-01766-0.