Gender Differences in Cardiovascular Performance While Running at Maximum Heart Rate: Emphasis on Phase Space Dynamic

The aim of present study was to examine the difference between the cardiovascular performance of women and men due to running effects using phase space dynamics.

Fifty four University students were voluntarily participated in this study and divided in two groups’ male (34 participants, 21.68±1.66 years old and 67.01±9.77 Kg) and female (20 participants, 22.4±5.33 years old and 54.1±5.79 Kg). Heart rate variability (HRV) parameters as a function of the cardiovascular system indices measured in these subjects. Using drawing the phase space dynamics and applying the Poincaré section, the features of the time-domain extracted. Data were analyzed by an independent t-test with a significance level (p<0.05).

The results of this study showed that the HRV parameters, i.e., P-Com, PNN50, HRmax, Tr, and  in men’s group significantly altered compared to the women’s group. We found that the average time for reach to maximum heart rate was higher in the women's group and that the average PNN50 and rMSSD parameters in the men's, were higher than the women's, which was stimulated by the parasympathetic and vagus nerve and affected. So this point demonstrated the slowest rhythm of the heartbeat in men.

According to the experimental results, during exercise activities, there is a phenomenon of hysteresis in the cardiac phase space arising from the chaotic and nonlinear dynamics of the biological system in the human body. Therefore, the analysis of these parameters indicates that the intervals between two consecutive beats are higher in men. Thus, they have fewer beats rhythm. Besides, this group is almost more physically fit than women are.