Differences in autonomic heart rate modulation during rest and after a supramaximal anaerobic test in relation to gender and the menstrual cycle in women

Abstract

Background / Aim. Heart rate variability (HRV) and heart rate recovery (HRR) show differences between genders and dissimilarities were, as well reported in women in various menstrual cycle (MC) phases. The goal of this research was to analyze cardiac autonomic indices during rest and in recovery after a Wingate test between genders in young, sedentary population and to investigate whether a MC phase can influence these indices. Methods. Twenty-five females (20.5±0.7 years) and sixteen males (20.4±0.7 years) performed a Wingate anaerobic test on a cycle ergometer with their HRR and resting and recovery HRV indices obtained. In females data were collected during three distinctive MC phases. Results. Natural logarithm of low frequency HRV marker (lnLF) and natural logarithm of high frequency HRV marker (lnHF) were higher in males during rest in regard to women in all MC phases, except in late follicular phase, where no differences in lnHF between genders were observed. Markedly higher lnLF and lnHF were recorded in males after the Wingate test. There were no differences in HRV between women in various MC phases during rest. Surprisingly, parasympathetic time domain marker (the square root of the mean squared differences of successive NN intervals, RMSSD) and lnLF were both higher in early follicular in compare to luteal phase during the recovery. HRR was faster in men in compare to women in all MC phases. Conclusion. In conclusion, males show greater HRR and total variability during rest and recovery, but it appears that resting parasympathetic activity is similar when females are in late follicular phase. Intra-female resting autonomic variability is not affected by sex hormonal cycle. Post-exercise HRV in early follicular phase reflects a significantly favourable autonomic profile in compare to luteal phase.