[Trends of physical development and adaptation to the study load and health-improving sports activities in elementary schoolchildren of Moscow].

Unlabelled: The inclusion of 7-10-year-old children in the school system occurs in the context of the interaction of two processes: activation of ontogenesis at this stage of age development and stimulation of biological and psychological adaptation of younger schoolchildren to the learning activity. The main factors negatively affecting the health of elementary school students are the following: hypokinesia, mental and psycho-emotional stress related to computer and digital learning technologies, prolonged stay in closed rooms of the educational institution rather than in the natural environment. In this regard, it is relevant to find ways to improve the adaptive capacity of children, their physical development (PD), musculoskeletal system (MS), and muscular core as a biological basis for learning activities.

Objective: To determine the trends of the state of regulatory systems (RS), adaptation, and PD in primary school children in Moscow shaped by preventive physical fitness (PF) classes developed within the framework of the federal state educational standard (FSES) to improve adaptation, PD, MS, and muscular core state.

Material And Methods: A pedagogical experiment was conducted; 120 schoolchildren of both sexes in the 1st-4th forms at two Moscow schools were examined during the initial stage of the experiment. All students were engaged in preventive physical fitness classes, including game-based activities and exercises embedded in the FSES for primary schools. More than 50% of students attended extracurricular sports sections in football (17.5%), ballroom dancing (10.0%), karate (6.6%), swimming (5.8%), gymnastics (including acrobatics) (5.0%), basketball (5.0%) and figure skating (3.3%). Diagnostic methods included: anthropometric methods to measure height, bodyweight using a stadiometer and automatic medical scales; dynamometer method, in standing position, arm with dynamometer extended horizontally at shoulder level; a motor test to determine coordination abilities; diagnostics of heart rhythm variability (HRV) using Varicard-Express hardware-software complex. The calculated HRV parameters were determined: a regulatory systems activity index (RSAI) to determine the adaptive capacity of the body, and stress index (SI) to assess the subject's exposure to stress.

Results: It was demonstrated that schoolchildren in the Moscow metropolitan area are characterized by slower growth processes with activation at 8-9 years instead of 6-7 years. The baseline RSAI values in all children were at level 5, which corresponds to the state of RS stress of the body. Preventive PF classes led to improved adaptation in 7-8-year-old children. The condition of 50% of schoolchildren based on SI was optimal; / (22%) of schoolchildren had the initial stage of psychoemotional stress, 18% (in total) of children had severe and extremely severe RS stress related to the school environment.

Conclusion: Monitoring of the RS adaptation and health state allows teaching, preventive, health-improving, and recreational activities in educational institutions with respect to individual and typological features of students, as well as minimizing the negative effects of the education digitalization on the physical and mental development of schoolchildren.