This paper aimed to study age- and sex-related characteristics of heart rate variability (HRV) in highly qualified cross-country skiers living in the European North of Russia. HRV in supine and standing position (orthostatic test) was analysed in 94 boys and girls aged between 15 and 18 years. Electrocardiogram (ECG) was recorded for 5 min in supine position and 5 min in standing position. The recordings were analysed using the Ecosan-2007 hardware and software complex. The research was conducted during the preparatory cycle. No effects of age or sex on HRV in skiers were detected in supine position; however, a decrease in heart rate in boys and girls aged 17-18 years was recorded. In standing position, the subjects showed certain sex-related differences in HRV. Boys aged 17-18 years, compared to girls, had significantly higher total power (TP) of the HRV spectrum, absolute and relative values of low-frequency (LF) power, and regulatory systems activity index (RSAI), as well as lower relative value of very low-frequency (VLF) power. No differences in the autonomic regulation of heart rhythm in boys and girls aged 15-16 years were revealed. With age, boys demonstrate an increase in TP due to the growing LF and VLF powers. Two-way analysis of variance revealed a statistically significant relationship between age and heart rate, root mean square of the successive differences (RMSSD), RSAI, TP, and absolute and relative VLF powers. A significant relationship was also established between sex and heart rate, RMSSD, RSAI, TP, power of the high-frequency component of HRV, absolute LF power, and relative VLF power. Thus, it was shown that an athlete`s age and sex produce a significant effect on HRV in standing position, but not in supine position.
© Copyright 2020 Journal of Medical and Biological Research. Northern (Arctic) Federal University named after M.V. Lomonosov. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator