The Effect of the Menstrual Cycle on Intestinal Damage During Running: Protocol and Initial Data

Methods: Females with a natural menstrual cycle (NC), females using the oral contraceptive pill (OCP), and males will be recruited to allow comparisons between sexes and within the female sex. Blood samples will be taken pre- and post-exercise and will be analysed for plasma concentrations of intestinal fatty acid binding protein to determine enterocyte damage, a dual sugar absorbance test to determine changes in intestinal permeability, and hormonal concentrations (oestrogen and progesterone). Despite the small sample size in the initial data, expected patterns of hormones and hypothesised patterns of EIDG were observed.