If a girl of about 12 years old has vaginal bleeding after running, it is considered to be vaginal bleeding caused by the first menstruation. If an adult woman of childbearing age has vaginal bleeding after running between menstrual periods, most of the bleeding is due to ovulatory bleeding, the amount of bleeding is usually not too much and the bleeding does not last more than a week, which is a normal physiological phenomenon. However, it is still necessary to take rest and avoid strenuous exercise to avoid a significant increase in bleeding. If a woman is approaching menopause and has this condition after running, it cannot be ruled out that it is due to menstrual disorders and endocrine disorders, especially in the case of heavy bleeding.