Effect of Endogenous 17B Estradiol on Core Temperature and Skin Blood Flow in Healthy, Eumenorrheic Women: A Report of Three Studies

摘要

These studies were done to describe the pre-ovulatory phase core temperature decrease in healthy, eumenorrheic women as a change in the regulated body temperature set point. In Study 1, subjects walked at a moderate exercise intensity wearing personal protective equipment. In Study 2, the environment mimicked that under the PPE in the first study during cycle exercise when dressed in t-shirts and shorts. In Study 3, the environment from the first study was used while the subjects exercised on a cycle ergometer. PPE was not worn in this last study. Subjects in all studies showed a decrease in resting core temperature and elevated serum estradiol for the pre-ovulatory phase experiments. In all studies, subjects (n=4; n=3; n=5; respectively) were studied in the early follicular phase (EF, days 2-6) and in the pre-ovulatory phase (PO, days 8-12) of the menstrual cycle. Lower resting core temperature (esophageal) and elevated serum estradiol for the pre-ovulatory phase experiments were observed in all subjects. Taken together, the observations from the three studies support the theory that there is a decreased regulated body temperature during exercise in the pre-ovulatory phase of the menstrual cycle. This finding holds despite varying clothing, mode of exercise and environmental conditions.