Shifting of menstruation in female athletes

: The menstrual cycle can be divided into 2 phases. During the trophotropic, or follicle, phase, energy is stored in anticipation of ovulation and a possible conception; at this time the sensation threshold is high. After menstruation, the ergotropic, or corpus-lateum phase, is marked by a dissipation of energy and a low threshold of sensation. Studies of male athletes show that an ergotropic type phase is observed during sport activity, followed by a trophotropic phase during rest. Thus, a woman's athletic potential is dependent on her place in the menstrual cycle. Women in sports which require endurance should compete during the follicle phase. In sports which require short-term, intense performance, women with ergotropic tendencies should compete during the follicle phase, and women with balanced or trophotropic tendencies should compete during the corpus luteum phase. Hormonal contraceptives can be used to regulate the menstrual cycle; this is not considered to be doping.