Changes in bioelectrical activity of the cerebral cortex in children aged 8–12 after interval hypoxic training

The period of early puberty is accompanied by significant cognitive, physical and emotional stress, which requires methods to optimize the functional brain state. Interval hypoxic training (IHT) activates adaptation mechanisms caused by hypoxia-inducible factor-1 (HIF-1), which increases the oxygen capacity of the blood, improve energy production and cerebral blood supply. Objective. The aim of the paper is to study the changes in the bioelectrical activity of the cerebral cortex in children aged 8–12 while adaptating to hypoxia during normobaric IHT. Materials and Methods. The study involved 95 boys aged 8–12 (main group – 50 trial subjects after IHT, comparison group – 45 trial subjects). Before the IHT, a hypoxic test was performed (10-minute inhalation of oxygen mixture (O2 10–14 %) with monitoring of SaO2, HR, BP, and saturation recovery time. IHT included sequences of hypoxia and normoxia: 5 days – 13 % O2, 5 days – 12 % O2, 5 days – 11 % O2. Compact-Neuro EEG electroencephalograph (16 leads, 10–20 system) was used to record cerebral bioelectrical activity at rest and under functional loads. Results. The hypoxic test revealed that when inhaling a mixture with 12 % O₂, the SaO₂ level decreased up to 85 % with a recovery to 97 % during the first minute of the recovery period, indicating the development of subcompensated hypoxia, which contributes to the activation of the body’s adaptive mechanisms. After IHT, the index and amplitude of alpha and beta rhythms increased, the index of theta and delta rhythms decreased. Moreover, reactions to functional loads improved, indicating increased alertness and neural network activity. Subjective improvement in concentration, memory, sleep quality and decreased anxiety indicate improved neuroplasticity and functional brain state. Conclusion. The obtained data demonstrate the IHT potential, as it can increase brain stress-resistance, and improve the adaptive capabilities of the central nervous system.