All living creatures are endowed with the rhythms of life – built into our very genetics is this beautiful beat of nature. We women are amazing and profoundly rhythmic. We have a daily rhythm, known as the Circadian Rhythm, a lunar rhythm, which correlates with our female menstrual cycle, and even seasonal rhythms, relating to the 365 day rotation of earth around our sun.
Sadly, a significant percentage of women suffer through their menstrual cycles, experiencing a host of physical and emotional symptoms. Severe mood swings occur during the second half of the cycle, known as the luteal phase. Menstrual cycle-related symptoms may include psychological symptoms, such as irritation or depressed feelings, or physical symptoms such as breast tenderness, swelling, headaches or stomach aches in the premenstrual and menstrual phases of the menstrual cycle.
The World Health Organization (WHO) estimated that 199 million women had premenstrual syndrome as of 2010, comprising nearly 6% of all women. Other reviews showed that about 10% of all women experience premenstrual syndrome, and about 70–90% of women experienced menstrual cycle-related symptoms.
Menstrual cycle-related symptoms are physiological and emotional in their impact and can affect health-related quality of life. According to one study, the average scores of students with premenstrual syndrome were significantly lower in all areas of quality of life. Clearly, reduction of these symptoms would contribute to the improvement of the quality of life for these young women.
Many studies, as mentioned, have revealed that symptoms are the worst during the luteal phase of the menstrual cycle, and stressful situations are associated with an increased occurrence of menstrual cycle-related symptoms.
Stress is known to affect cardiovascular changes, which are usually related to autonomic nervous system activity alterations. The autonomic nervous system is comprised of the sympathetic and parasympathetic nervous systems. The sympathetic is activated with stress and the parasympathetic is associated with rest and calm.
An analysis of a measure of stress — which correlates why the autonomic nervous system state, known as heart rate variability (HRV) — provides an excellent sensitive, non-invasive measure of the effects of the state of the autonomic nervous system upon cardiac regulation. The heart mirrors the state of stress and the balance of the sympathetic and parasympathetic nervous system state of being.
There are two main frequency components of HRV, low frequency (LF: 0.04–0.15 Hz) reflecting both sympathetic and parasympathetic nervous system activity, and high frequency (HF: 0.15–0.40 Hz) reflecting the activity of the parasympathetic nervous system. Consequently, the LF-to-HF (LF/HF) ratio represents the sympathetic/parasympathetic balance. In previous studies, HF was lower in the luteal phase than the follicular phase, indicating increased sympathetic nervous activity in the luteal phase and increased parasympathetic nervous activity in the follicular phase. This would translate into more stress and anxiety in the luteal phase of the cycle. And not surprisingly, sympathetic nervous activity is stronger in women with severe menstrual symptoms than in those with less severe symptoms.