Menstrual Cycle Effects on Aerobic Performance

Currently only 33% of females meet the recommended weekly guidelines for aerobic exercise, 150-minutes of moderate activity or 75-minutes of vigorous activity weekly. Each month premenopausal females also go through a complete menstrual cycle phase (MCP) that is a cyclical routine on every 21 to 35 days. Throughout these phases there are fluctuations in female sex hormones such as estrogen, progesterone, follicle stimulating hormone and luteinizing hormone. Estrogen has an effect on glucose metabolism and increases gluconeogenesis. This is important because glucose is the primary fuel substrate for aerobic activity and exercise. The shift in thermoregulatory set point (98.8°F) is associated with elevated progesterone levels found in the luteal phase which can potentially impact performance, a key point when it comes to aerobic training. This research project is interested in understanding if different MCPs have an effect on variations in VO₂ performance (the max rate of oxygen the body can consume and use during exercise), heart rate, and psychological perceived exertion. Researchers hypothesize that during the follicular phase is when females may observe more favorable feelings and effort of exertion. During this phase progesterone is lower and estrogen rises. Researchers are recruiting 5 females to participate in this study and the participants will come in and complete VO₂ max testing during the follicular phase, menstrual phase, and early luteal phase of their MCP. Researchers are comparing these phases to see if VO₂ response is higher or lower in specific phases, if there are changes in psychological performance, and if there are alterations in heart responses to aerobic activity.