While many people immediately assume that a missed period means pregnancy, a woman may miss a period for many other reasons. Physical and emotional conditions that disrupt the body's hormones levels, such as drastic weight loss or gain, eating disorders, stress and anxiety, thyroid disease and pituitary disease, can disrupt the normal menstrual cycle. Another cause of missed periods is habitual, excessive exercise. While regular exercise is important for maintaining a healthy weight and preventing obesity-related diseases, excessive strenuous exercise can prevent the release of estrogen, which is required for menstruation.
Estrogen
Excessive exercise, especially when coupled with a poor or abnormal diet, can prevent menstruation if the woman's body fat is lowered too much. When body fat percentage is too low, the ovaries stop producing estrogen, which in turn prevents menstruation. During the beginning of a woman's menstrual cycle, ovarian follicles produce the hormone estrogen. Estrogen causes the lining of the uterus to thicken in preparation for the implantation of a fertilized egg and signals the most mature follicle to release an egg. If the egg is not fertilized by a sperm within its 24-hour lifespan, the body sheds the uterine lining, resulting in menstruation. Without the necessary body fat that leads to the release of estrogen, a woman will not menstruate.
Body Fat
A missed period is a strong indication that a female athlete's percentage of body fat is too low. While there is no hard rule on what body fat percentage is considered too low for all women, the minimum body fat percentage for normal ovulation is around 17 percent. Most experts in the medical community believe that a healthy body fat percentage for women is 22 percent. A health professional can measure body fat several ways, including measuring skin thickness with calipers and using dual-energy x-ray absorptiometry.
Cutting Back
Women who exercise a lot and have missed a period should decrease the intensity and frequency of the workouts. If the cause of the missed period is too much exercise, simply cutting back on the intensity and frequency of the workouts will help. Following a consistent and healthy diet will also help normalize the body's body fat percentage.
Professional Help
Even if strenuous exercise is the likely cause for the missed period, sexually active women should always take a pregnancy test to rule out pregnancy. Women who have previously menstruated but miss three or more periods in a row, a condition referred to by the medical community as secondary amenorrhea, should see a medical professional. Treatment depends on the cause of the secondary amenorrhea, which the doctor will determine by performing a physical examination, conducting tests and asking lifestyle questions. Secondary amenorrhea may simply be due to exercising too much, for which the doctor will recommend a normal exercise routine and nutrition plan. However, secondary amenorrhea can also be caused by a serious medical condition, such as a thyroid disorder or polycystic ovarian syndrome, which require professional treatment.
References
- Feminist Women's Health Center: Menstrual Cycles: What Really Happens in Those 28 Days?!
- University of Iowa Hospitals and Clinics: Athletic Amenorrhea
- MedlinePlus; Menstruation - Absent; David Zieve, MD, et al.; June 2010
- BabyCenter; I'm underweight and have low body fat. Will this affect my ability to get pregnant?; Spencer Richlin
- "Scientific American"; Going for the Gaunt: How Low Can an Athlete's Body Fat Go?; Katie Moisse; February 2010
