Doctor Biological Sciences, Professor M.V. Shaikhelislamova¹
PhD Biol., Associate Professor N.B. Dikopolskaya¹
PhD Biol., Associate Professor G.A. Bilalova¹
PhD Biol., Associate Professor A.A. Sitdikova^1
1Kazan (Volga Region) Federal University, Kazan

Objective of the study is to study the reaction of the sympathetic-adrenal system to dosed physical activity in children 7-9 years old, taking into account the initial autonomic tone, age and gender.
Methods and structure of the study. The study was conducted with the participation of 7, 8, 9 year old children of both sexes studying in a secondary school. Initial autonomic tone was assessed using the method of variation pulsometry using the Reo-Spectrum hardware and software complex from Neurosoft. Adaptive reactions of the sympathetic-adrenal system were studied by shifting the excretion of adrenaline, norepinephrine, dopamine and DOPA in portioned urine in response to a dosed bicycle ergometric load of moderate, based on the fluorometric method. Urine was collected before exercise and an hour after it.
Results and conclusions. The study found that the reaction of the sympathetic-adrenal system to dosed physical activity is unstable and depends on the initial autonomic tone, age and gender of the children. Sympathotonic boys aged 7 years are characterized by high mobilization readiness of the sympatho-adrenal system with increased consumption of its functional reserves. Vagotonia - a more balanced version of neurohumoral regulation is accompanied by a simultaneous increase in the excretion of adrenaline and norepinephrine, an increase in dopamine and DOPA. Boys 9 and girls 7 years old deserve special attention, in whom, in response to dosed physical activity, there is a significant increase in catecholamines and their precursors, regardless of autonomic tone. This is a condition for stable and long-term physical performance of the child’s body and allows us to recommend this particular age as the most favorable period for starting systematic physical training and sports.

Keywords: autonomic tone, catechol amines, physical activity, children 7-9 years old.

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