Influence of regular exercise on cardiac autonomic activity in healthy young women during the normal menstrual cycle

Regular physical exercise leads to considerable changes demonstrated in the increase of health related fitness. Heart rate variability is a measure of autonomic nervous system function. Gonadotropin hormones affect autonomic nervous system function. Regular exercise is thought to modulate the sympathovagal control of the heart leading to an enhancement of the vegetative control of the heart. The present study aims to describe the heart rate variability and assesses its association with regular exercise and menstrual cycle in healthy young women in frequency domain method in different phases of menstrual cycle. A total of 54 female students were selected. The selected students were divided into two groups namely Group I consisted of subjects doing regular physical exercise for 30 minute each day and Group II consisted of individuals who were non exercisers the ECG recording were taken during the 3 phases of menstrual cycle. The analog ECG signal were conveyed through an A/D converter to PC and were analyzed . The frequency domain analysis was done in which the LF, HF and LF/HF components were studied. Results showed that a significant increase in the LF/HF ratio in the luteal phase of menstrual cycle in the non exercisers group when compared to other phases of the menstrual cycle (P<0.001). Regular exercisers had more parasympathetic activity than non exercisers. Detection of sympatho vagal inbalance at an early age based on regular exercising with necessary life style modification could decrease the incidence of cardiovascular diseases as age advances.