Amenorrhea (uh-men-o-REE-uh) is the absence of menstruation, often defined as missing one or more menstrual periods.
Exercise-induced amenorrhea (EIA) is a condition where women experience an absence or irregularity of their menstrual periods due to intense physical activity. It is common among female athletes and women who engage in regular strenuous exercise. EIA is a significant concern for women’s health, as it can have long-term consequences, including reduced bone density, increased risk of fractures, and fertility issues.
The menstrual cycle is regulated by the hypothalamus-pituitary-ovarian (HPO) axis. Exercise can disrupt this delicate balance by affecting the release of certain hormones, such as estrogen, progesterone, and luteinizing hormone (LH). High-intensity exercise can result in a decrease in estrogen production, which can lead to changes in the menstrual cycle. Estrogen is essential for maintaining the uterine lining, and when levels are too low, the lining may not build up properly, leading to a missed period.
Several factors can contribute to EIA, including low body weight, low body fat, and high levels of physical activity. These factors can trigger a chain reaction that disrupts the HPO axis and results in amenorrhea. Additionally, stress can also contribute to EIA, as it can cause a decrease in the production of the hormone GnRH (gonadotropin-releasing hormone), which is responsible for triggering the release of LH and follicle-stimulating hormone (FSH)
How does the menstrual cycle work?
A complex system of hormones controls the menstrual cycle. Every month, hormones prepare the body for pregnancy. Ovulation then occurs. If there is no pregnancy, the cycle ends with the uterus shedding its lining. That shedding is the menstrual period.
The hormones responsible for this cycle originate in different parts of the body. A dysfunction in any of these parts can prevent a person from getting a period:
- Hypothalamus, which controls the pituitary gland.
- Pituitary gland, called “the master gland,” which produces the hormones that instruct the ovaries to ovulate.
- Ovaries, which produce the egg for ovulation and the hormones estrogen and progesterone.
- Uterus, which responds to the hormones and prepares the lining. This lining sheds as the menstrual period if there’s no pregnancy.
What are the types of amenorrhea?
There are two classifications of amenorrhea:
- Primary amenorrhea is when you haven’t gotten a first period by age 15 or within five years of the first signs of puberty. It can happen due to changes in organs, glands, and hormones related to menstruation.
- Secondary amenorrhea is when you’ve been getting regular periods, but you stop getting your period for at least three months, or you stop your menses for six months when they were previously irregular. Causes can include pregnancy, stress, and illness.
Who is at risk for amenorrhea?
Risk factors for amenorrhea include:
- Family history of amenorrhea or early menopause.
- A genetic or chromosomal condition that affects your menstrual cycle.
- Obesity or being underweight.
- Eating disorder.
- Poor diet.
- Chronic illness
In this article Certified Fitness & Nutrition Consultant Leena Doshi will discuss about Exercise Induced Amenorrhea:
What is Exercise-Induced amenorrhea?
When women stop having monthly periods due to excessive exercise, it is called exercise induced amenorrhea.
The most common cause of amenorrhea in athletes is what is known as functional hypothalamic amenorrhea (FHA). The hypothalamus is a regulatory center in the brain that releases hormones, which control multiple bodily systems, including the reproductive system.
In FHA, the hypothalamus is ‘silenced’ from releasing hormones that ultimately allow for ovulation and a normal menstrual cycle. FHA is caused by low energy intake, exercise, weight loss, stress, or a combination of these factors.
What causes Exercise-Induced amenorrhea?
The combination of low body weight and low fat percent below 14 % and intense exercise causes the starvation state in the body. The starvation state shorts down the reproductive system causes amenorrhea and even infertility.
2. Release of Stress hormone
Even among female athletes that train hard and eat plenty, amenorrhea is common. The biological explanation for this lies in the release of “stress hormones” that are part of the body’s normal response to exercise. These “stress hormones” are similar to those released during “fight or flight” situations, and are also what makes people feel so good after exercising (post-workout euphoria). Unfortunately, these “stress hormones” interfere with the brain’s production of the reproductive hormones necessary to keep the menstrual cycle flowing.
Consequences of Exercise-Induced Amenorrhea (EIA)
Most women actually don’t mind it so much when their periods stop coming. And in fact, menstruation can be a big inconvenience, particularly for competitive athletes. But many women are not aware of the serious long-term health consequences of exercise-induced amenorrhea.
Because of the altered production of reproductive hormones, women with exercise-induced amenorrhea are estrogen-deficient. Estrogen is one of the most important female hormones, and when there is too little of it, the health risks include infertility, atrophy of the vagina and breast, and osteoporosis (which can lead to fractures of the spine, hip, and other areas). Prolonged exercise-induced amenorrhea may also increase the risk of heart attacks later in life.
Treatment of Exercise-Induced Amenorrhea (EIA)
Once the diagnosis is confirmed, the main objective of treatment is to restore estrogen levels to the normal range. In many women, this can be accomplished by increasing caloric intake so that the body exits a “starvation state.” In women who are reluctant to increase their calories, estrogen can be given in the form of birth control pills or patches.
It can also be given as hormone replacement therapy, similar to that used by postmenopausal women. Such treatments will protect a woman’s bones from fractures due to osteoporosis, but will not treat her infertility. Infertility due to exercise-induced amenorrhea can be treated with fertility medications, but if a woman is underweight, optimizing body weight by improving nutritional intake before trying to get pregnant is the preferred approach.
In conclusion, exercise-induced amenorrhea is a condition that can have long-term consequences for women’s health. Women who engage in high-intensity exercise should be aware of the risks and take steps to prevent the development of EIA. It is essential to maintain a healthy body weight and body fat percentage and to seek medical attention if irregularities in the menstrual cycle occur. By taking these steps, women can maintain their health and continue to engage in the physical activity they enjoy.
- Warren MP, Perlroth NE. The effects of intense exercise on the female reproductive system. J Endocrinol. 2001;170(1):3-11. doi: 10.1677/joe.0.1700003.
- Loucks AB. Energy balance and body composition in sports and exercise. J Sports Sci. 2004;22(1):1-14. doi: 10.1080/0264041031000140536.
- De Souza MJ, West SL, Jamal SA, et al. The presence of both an energy deficiency and estrogen deficiency exacerbate alterations of bone metabolism in exercising women. Bone. 2008;43(1):140-148. doi: 10.1016/j.bone.2008.03.019.
- De Souza MJ, Miller BE, Loucks AB, et al. High frequency of luteal phase deficiency and anovulation in recreational women runners: blunted elevation in follicle-stimulating hormone observed during luteal-follicular transition. J Clin Endocrinol Metab. 1998;83(12):4220-4232. doi: 10.1210/jcem.83.12.5299.
- Ackerman KE, Slusarz K, Guereca G, et al. Higher ghrelin and lower leptin secretion are associated with lower LH secretion in young amenorrheic athletes compared with eumenorrheic athletes and controls. Am J Physiol Endocrinol Metab. 2012;302(7):E800-806. doi: 10.1152/ajpendo.00623.2011.
- Hoch AZ, Pajewski NM, Moraski L, et al. Prevalence of the female athlete triad in high school athletes and sedentary students. Clin J Sport Med. 2009;19(5):421-428. doi: 10.1097/JSM.0b013e3181b8c270.
- De Souza MJ, Williams NI. Physiological aspects and clinical sequelae of energy deficiency and hypoestrogenism in exercising women. Hum Reprod Update. 2004;10(5):433-448. doi: 10.1093/humupd/dmh037.
- American College of Sports Medicine. Exercise and Women’s Health: Position Stand. Med Sci Sports Exerc. 1998;30(6):i-x. doi: 10.1097/00005768-199806000-00002.
- National Institute of Child Health and Human Development. Amenorrhea: Condition Information. https://www.nichd.nih.gov/health/topics/amenorrhea/conditioninfo. Accessed February 18, 2023.
Fitness & Nutrition Consultant