Autonomic providing cardiac rhythm of middle-aged women with long-term regular training experience of aerobic orientation

Résumé

Aim. To study the influence of regular training with aerobic orientation on heart rate variability of middle-aged women with long-term training experience.

Materials and methods. In the work the results of research autonomic providing cardiac rhythm of 19 women, who were divided into two studied groups are presented. The first study group consisted of 10 women who had experience of regular training (3 times a week) aerobic orientation from 3 to 5 years, the average age of this group of women was 37,9±5,9 years. The second study group consisted of 9 women with regular training experience with aerobic orientation over 10 years, the average age of women – 44,6±5,5 years. At this stage we defined the specific features autonomic heart providing, that was characterized on the basis of the analysis of heart rhythm variability results. For this purpose it was used the device – spiroarteriocardiorhythmography, which in simultaneous mode register defines the parameters of heart rate, systolic and diastolic blood pressure for each heart reduction. According to data the measuring of sequences cardiac rhythm, systolic and diastolic blood pressure variability and data respiratory ventilation was conducted by Fourier's spectral analysis, which determines the capacity of regulatory influences on three frequency ranges: very-low-frequency (VLF, 0–0,04 Hz), low-frequency (LF, 0,04–0,15 Hz) and high-frequency (HF, 0,15–0,4 Hz), what are measured in the absolute values of power (ms²). Additionally there was a spectral method determined by data of sensitivity arterial baroreflex (SBR, ms/mmHg) – α-coefficient, what calculated in ranges high (SBR_HF) and low (SBR _LF) frequencies, connecting with a total activity, activity of over-segmental structures, parasympathetic and sympathetic branches of autonomic nervous system.

Results. Research results showed difference in heart rate variability of parameters observed only for high-frequency components, which was significantly (p<0,05) lower in second study group. In this case, women of that group had a tendency to a slight sympathetic predominance and in the first study group– parasympathetic influences. As for the other components the power spectrum of heart rate variability, it should be noted that there is a certain tendency that certifies reduction of general and all constituents power spectrum of heart rate variability in the second study group.

Results of determination of sensitivity arterial baroreflex of women demonstrate the positive impact of training on the mechanisms autonomic regulation in the high-frequency range, which because of long-term experience significantly reduced.

It can be asserted that increasing the term of training with aerobic orientation leads to increased low-frequency (sympathicotonic) but decreased high-frequency (vagotonics) effect on cardiac rhythm.

Conclusions. The studies which were conducted revealed, that women in second study group have, unreliable, but a significant increase in activity of regulatory impact in very-low-frequency range, that in our opinion could be predefined by physiological characteristics of an organism at the age that group of women. The biggest changes come from the decrease in activity of regulation in high-frequency range with increasing the term of training. The latter is confirmed by probable decrease in autonomous control for the indicators of sensitivity arterial baroreflex in a high-frequency range