Variation in physiological function within and between menstrual cycles: uncovering the contributing factors

Sex matters in neuromuscular control

“…Sex hormones have extensive effects on many physiological systems throughout the human body and differ between the sexes. In eumenorrheic females, endogenous levels of estradiol and progesterone fluctuate regularly across the menstrual cycle and these fluctuations have been associated with aspects of motor control, 9 including motoneuron firing rates and fatigue. At a more basic level, neurons throughout the body (ie throughout the cortex, brainstem, and spinal cord) contain estradiol and progesterone receptors, suggesting that fluctuating sex hormones may impact neuronal function, including that of motoneurons.…”

The art of facilitation: a delicate hormonal balance!

“…Although differences in sex hormones are present throughout early life, the pattern of expression is most divergent from the onset of puberty with the establishment of the menstrual cycle in females and a rise in circulating testosterone in males. Once sexual maturation is established in females, 17β-oestradiol and progesterone express cyclical fluctuations with every menstrual cycle until menopause with recent publications suggesting that, similar to other systems, variability between consecutive menstrual cycles adds an additional level of complexity (McNulty et al, 2021).…”