Functional hypothalamic amenorrhea in athletes

For runners, lifters, and other female athletes who function at high volume levels, losing your period is not uncommon. But “common” does not equate to “normal.” While this may seem ideal to avoid the symptoms that come along with menstruation, regular periods are indicators of health and losing your cycle is a clear sign of dysfunction in the body.

While many women view the lack of a menstrual cycle as a blessing, our period is often referred to as our fifth vital sign for providing insight into a woman’s health and is directly linked to brain function at a core level. Healthy women have regular menstrual cycles with little pain, PMS, or heavy bleeding. When the menstrual cycle disappears for a woman who is physically active, functional hypothalamic amenorrhea (FHA) is often the culprit.

In this article we’ll discuss how our body functions normally to give you an understanding of what goes wrong with FHA, as well as some of the leading causes and recommended interventions to help bring your menstrual cycle back into balance as an athlete. Read on to learn:

• Why do female athletes like runners, cyclists, and other heavy exercisers often lose their periods? Is this normal?
• What causes functional hypothalamic amenorrhea (FHA)? How do I know if I have FHA?
• What are the health impacts of period loss for athletes?
• How do you fix FHA?

All about the hypothalamus: Our “center of hormones”

The hypothalamus is a portion of the brain that maintains the body’s internal balance and helps stimulate and inhibit many of the body’s key functions including blood pressure, body temperature, appetite, body weight, sleep cycles and the production of hormones that influence the pituitary and other endocrine glands throughout the body.

Sitting at the center of the brain, the hypothalamus is responsible for producing and releasing a range of hormones. One such hormone is gonadotropin-releasing hormone (GnRH), which stimulates the hormones necessary for ovulation, including follicular stimulating hormone (FSH) and luteinizing hormone (LH), which subsequently release estrogen. This system comprises the hypothalamic-ovarian axis.

When the hypothalamus stops producing adequate GnRH, hormonal triggers throughout the reproductive system fail to occur and ovulation stops, along with menstruation as a result.

While young women in adolescence are more at risk for developing FHA, this condition exists for women of all ages. Along with loss of a menstrual cycle, FHA creates other health concerns as discussed below.

Causes of period loss, or functional hypothalamic amenorrhea (FHA)

Whether you’re looking to determine the cause of losing your cycle or aiming to prevent this from happening as an athlete, the underlying causes of FHA typically fall into three categories:

1. Insufficient energy intake
2. Excess physical exercise
3. High stress levels

This is often referred to as the female athlete triad, and these factors have one theme in common in that they put the body under significant stress, which alters the hypothalamus ability to function properly.

The hypothalamus is directly linked and affected by all hormones in the body including cortisol, our stress hormone. Typically known as our “fight or flight” hormone, cortisol is released under stressful situations, whether it’s exercise, being in physical danger, or emotionally distressed. Cortisol and stress affect the hypothalamic-ovarian axis, as increasing levels of cortisol inhibit GnRH secretion. This helps to explain why times of high stress can lead to irregular menses and amenorrhea.

Low energy availability is one of the most common stressors to a female athlete’s body, and is associated with hypothalamic dysfunction and, subsequently, decreased menstrual function. This is an ongoing concern as many female athletes strive to lower their body fat composition, weight and BMI to perform optimally.

This issue also stems from the perception that women should not consume more than 1,2000 calories per day, even though the basal metabolic rate for most women is higher than this level. Basal metabolic rate (BMR) is the rate of energy expenditure required as rest, which means that many women have the perception that they are over-eating when consuming less than 1,200 calories, when in reality they are consuming less the amount of calories needed to simply survive. This doesn’t take into account the additional energy expenditure required by physical activity or normal daily functions in the equation, which means that women are often in an excessive calorie deficit.

Adequate calorie intake in addition to appropriate protein, carbohydrate, fat and vitamin balances play a role in ensuring enough energy is provided to the body for not only base level energy expenditure needs, but also physical activity and training regimens. When the body expends more energy than it consumes, its utilizes the calories and energy from food to continue baseline functions such as digestion in hopes to resolving the issue, while outlying health factors such as the ability to produce sex hormones for reproduction are secondary to survival and shut off as a result.

High energy expenditure as a result of high volume training regimens can also play a role in creating this energy imbalance in the body. All training and physical exercise put stress on the body and stimulate the release of cortisol into the bloodstream. This only creates negative effects when there are not enough calories to fuel that exercise or when conducted at high volume levels without adequate recovery strategies.

In addition to external stress on the body from insufficient calorie intake and physical exercise, internal stress including emotional stress and digestive dysfunction can play a role in creating imbalances in the amount of cortisol being secreted on a regular basis.

FHA is a “diagnosis of exclusion,” which means that physicians typically rule out other reproductive imbalances like PCOS before accepting FHA as the official diagnosis.

Health impacts of FHA for athletes

So, why does period loss matter for you as an athlete?

First, menstrual cycles serve as a vital sign of health. At the point that a women’s menstrual cycle disappears or becomes irregular, the fire alarm is going off. Our bodies will attempt to make every concession possible before shutting off the function of our sex hormones.

Without estrogen in particular being produced, FHA can have significant impacts on metabolic, bone, cardiovascular, mental and reproductive health. Estrogen aids in bone health by balancing the osteoclast and osteoblast activity to develop strong bones, which is why women typically suffer from osteoporosis as estrogen levels drop later in life. In general, approximately 20 to 50 percent of elite female athletes meet criteria for low bone density. Without the assistance of estrogen at relatively young ages as athletes, this becomes an even larger concern.

Athletes have a higher incidence, stemming from the synergistic relationship that exercise and low weight have on puberty and the menstrual cycle, but this extends beyond adolescent years when young women are most at risk for developing FHA.

In addition to low bone density risks, FHA can create irreversible effects on the reproductive system when left untreated, including infertility as well as early menopause, cardiovascular and muscular dysfunction, and vaginal and breast atrophy.

Treatment protocol for FHA

The goal of treatment of FHA and the resulting downstream symptoms is a multi-pronged approach to support the entire body by supplying adequate calories through nutrient-dense foods, as well as reducing exercise volume and intensity to moderate levels. In many cases, weight gain is an essential component for ensuring the resumption of menses, which serves as the best indicator that the hypothalamic dysfunction and low estrogen levels have been resolved.

Working with a sports nutritionist who can provide guidance and support for appropriate calorie intake around training. A coach or trainer may also be beneficial for support and guidance around exercise intensity that align with the reversal of FHA. For athletes who struggle with the mental aspect of increasing food intake or those who struggle with eating disorders should also consider a mental health professional as part of their team for promoting FHA healing.

As a last resort, it may be necessary in some FHA cases to replace hormones with physiologic dosing of transdermal estrogen and cyclic progesterone for the benefit of the young woman's bone health. While some physicians recommend the use of hormone birth control to replace hormone levels in the body, this will not allow the athlete to get to the root of the issue and instead cover up the amenorrhea by producing a withdrawal bleed on a monthly basis.

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