1. Korkushko OV. Analysis methods and age norms of heart rate variability. Guidelines. Kiev: Health; 2018.
2. Lisovsky B. Functional reserves of the cardiorespiratory system as an indicator of human health. Bulletin of the Precarpathian University. Series: Physical culture. 2016;2:31-4.
3. Dovganyk MS, Chichkan OA, Strelchenko VV, Yavorsky OG. Changes in the cardiovascular system of men and women during long-term health running. Slobozhansky scientific and sports bulletin. 2017;2:76-9.
4. Korobeynikov GV, Korobeynikov LG. Features of autonomic regulation of heart rhythm in wrestlers of different age groups. Pedagogy, psychology and medical and biological problems of physical education and sports. 2018;4:22-6.
5. Mikhailov VM. Exercise testing under ECG control: bicycle ergometry, treadmill test, step test, walking. Ivanovo: publishing house. IGMI; 2019;123.