A female runner’s performance truly depends on which stage of the menstrual cycle she is in. The menstrual cycle has been typically thought of being twenty-eight days, but in reality it can range between twenty-one and thirty-five days, depending on the woman. There are three phases to a woman’s menstrual cycle: menstrual, pre-ovulatory, and post-ovulatory.
A lot of women complain that in the days leading up to menstruation, running just seems harder. This is due to the levels of progesterone and estrogen dropping during the pre-menstrual period. Both hormones decline to the fourteenth day, but the progesterone climbs to a peak on the twentieth day. This is the major hormone that causes pre-menstrual syndrome (pms), which can leave a female feeling fatigued and moody. This point in the cycle is called the mid-luteal phase and is about a week after ovulation or about a week before menstruation actually begins. During this time, exercise becomes more difficult and ventilation rates increase due to progesterone stimulating the brain’s respiratory center. Because of that, many women find that exercise feels harder. This not the time to do speed work or to expect top performance in a race. However, the mid-luteal phase is the perfect time to store glycogen in the muscles. Recent research shows that glycogen storage is 22% higher in the leg muscles of females in the mid-luteal phase, compared to before ovulation. It also shows that the total endurance performance tends to be about ten percent greater. So this may actually be the best time to run a marathon because of the added glycogen stores. Non-menstruating women and women taking oral contraceptives don’t have a mid-luteal phase; therefore, don’t have to worry about negative psychological and physical changes.
Any sport can have an effect on the cycle of a menstruating woman. Running can place stress on the body and could lengthen or shorten the time of menstruation. It could also lead to irregular cycles, called oligomenhorrhea and cessation of the cycle, called amenorrhea. Amenorrhea is not good for the body. It can lead to osteoporosis, decreased calcium absorption, decreased bone density, and an increase in musculoskeletal injury. A high calcium intake is essential, around 1200mg per day. If a woman experiences irregularities in her cycle, she should consult her doctor.
During the mid-luteal phase, a female runner should listen to her body and train by ratings of perceived exertion. To combat PMS, eat a well-balanced diet. Limit the amount of refined sugar, red meat, salt, alcohol, saturated fats, and caffeine. PMS symptoms have been linked to low levels of magnesium, which affects blood sugar levels and hormonal metabolism. Add foods rich in magnesium, B vitamins, and calcium to the diet, such as fish, beans, and green leafy vegetables.
A female runner should listen to her body, adjust workouts as needed, and push it when she’s feeling great. It’s best if she learns to train with her cycle, not against it.
Written by Genie Bianchi, RRCA Coach