Patterns of physical activity among women and men before and during pregnancy

The menstrual cycle is a recurrent sequence of changes in the uterine endometrium, specifically its functional layer, the stratum functionalis. This cycle prepares the uterus for potential pregnancy. This cycle typically spans 21–35 days, averaging 28 days, and aligns with the ovarian cycle, regulated by fluctuating levels of ovarian hormones, primarily estrogen and progesterone.
The menstrual phase occurs from days 1 to 5 and involves the shedding of the stratum functionalis, as a...

The ovarian cycle regulates endometrial changes throughout a single menstrual cycle via the coordinated action of gonadotrophin-releasing hormone (GnRH) and gonadotrophins.
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH...

Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when...