Menstrual Cycle and Physical Effort

In addition to affecting the sexual organs in women, ovarian hormones have a wide impact on processes related to metabolism, water and electrolyte balance, thermoregula tion, and redox balance. Differences in the estradiol and progesterone concentrations during the follicular and luteal phases, as well as the increase in the concentration of these hormones under the influence of physical exercise, may cause a different course of exercise response in women depending on the phase of menstrual cycle. Estrogens affect the metabolism of women by reducing the rate of gluconeogenesis and glycogenolysis and, at the same time, by increasing the share of lipids in covering energy requirements. Progesterone affects respiratory system parameters causing, among others, an increase in pulmonary ventilation. The resultant antagonistic action of progesterone and estra diol is the effect on thermoregulatory mechanisms. Increased estradiol concentration at the low progesterone concentration level causes water and electrolyte retention. In turn, an increased level of progesterone leads to loss of water and sodium, causing a decrease in the volume of plasma during the postovulatory phase of the menstrual cycle. The pro cesses described above are related to metabolic changes affecting the ability to perform physical efforts.