To monitor the menstrual cycle, we performed daily virginal smears as previously described.14 and 15 Each phase of menstrual cycle is characterized by superficial nucleated cells for proestrus, superficial cytode cells for estrus, superficial nuclearted cell plus luekocyte for metestrus, and flourish leukocyte for anestrus, respectively. At the end of the 6-week intensive treadmill training, ovary epithelial cells changes were obvious as an outcome. Rats in group E showed longer duration of anestrus phase with a large number of small underlayer cells and delayed onset of estrus while typical middle layer cells were found in rats from groups R, G, and O, respectively