Female Athlete Triad: Part 1

In the world of sports and fitness, there is no denying that female athletes are pushing their bodies to the limit. But sometimes, this passion for performance can take a toll on their overall health, particularly when it comes to their menstrual cycles and reproductive health. In this blog post, we'll explore the Female Athlete Triad and amenorrhea in simple terms, so you can better understand these crucial health topics.

What is Amenorrhea?

Amenorrhea may sound like a complicated term, but it simply means the absence of a menstrual period. For many women, having a regular menstrual cycle is a sign of good health, indicating that their bodies are functioning as they should. However, in some cases, like with female athletes, this essential bodily function can be disrupted. Some women may experience, oligomenorrhea instead, which is when there are infrequent or irregular menstrual periods. Specifically, it refers to menstrual cycles that occur at intervals of 35 days or longer (28 days is a ‘normal’ cycle). Both indicate that there may be suboptimal functioning of the essential body processes that lead to normal menstrual cycles.

The Role of Caloric Balance

One major factor that can lead to amenorrhea in female athletes is an imbalance between the number of calories they burn through exercise and the number of calories they consume. This imbalance can be quite common among athletes who participate in sports with high energy demands, like long-distance running, dance, gymnastics, or figure skating. When your body doesn't get enough calories to fuel all the activities you do, it goes into a kind of "emergency mode." Your body thinks it needs to conserve energy, so it might reduce or even stop your menstrual cycle temporarily. This can be alarming, but it's your body's way of trying to protect itself.  

The Hypothalamic-Pituitary-Ovarian (HPO) Axis

To understand why this happens, let's talk about something called the HPO axis. The HPO axis, or the Hypothalamic-Pituitary-Ovarian axis, is a critical part of the endocrine (hormonal) system that plays a central role in regulating the reproductive functions in the female body. It involves three main components: the hypothalamus (a region in the brain), the pituitary gland (a pea-sized gland located at the base of the brain), and the ovaries (the female reproductive organs).

In a simplified manner, here's how the HPO axis works in a healthy reproductive cycle:

Hypothalamus: The hypothalamus in the brain is the starting point of the HPO axis. It monitors the levels of sex hormones, including estrogen and progesterone, in the bloodstream. When these hormone levels drop, as can happen in a normal menstrual cycle, the hypothalamus releases a hormone called Gonadotropin-Releasing Hormone (GnRH).

Pituitary Gland: GnRH travels from the hypothalamus to the pituitary gland, where it stimulates the release of two key hormones: Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). FSH and LH are essential for regulating the menstrual cycle.

Ovaries: FSH and LH, released from the pituitary gland, travel through the bloodstream to the ovaries. In the ovaries, these hormones play crucial roles in regulating the growth and release of eggs, as well as the production of female sex hormones, primarily estrogen and progesterone.

The HPO axis is a tightly regulated feedback system, ensuring that the right levels of hormones are produced at the right times to control the menstrual cycle, ovulation, and other reproductive functions. However, disruptions in this delicate balance can lead to various reproductive health issues, one of which is hypothalamic amenorrhea.

How Caloric Imbalance Can Lead To HPO Axis Suppression

Hypothalamic amenorrhea is a condition characterized by the absence of menstrual periods due to the suppression of the HPO axis. One common cause of HPO axis suppression is a caloric imbalance, where caloric expenditure (the energy burned through physical activity and other bodily functions) is significantly greater than caloric intake (the energy obtained from food).

This is caused by a variety of mechanisms:

Energy Deficit: When a person consistently consumes fewer calories than their body needs to support its functions and activities, the body perceives this as a state of energy deficit or starvation.

Survival Mode: In response to this energy deficit, the body goes into a kind of "survival mode." It prioritizes essential functions and attempts to conserve energy for critical bodily processes.

Hormonal Changes: The hypothalamus, which monitors energy balance, interprets this energy deficit as a threat to the body's well-being. In an effort to conserve energy, it may suppress the release of GnRH, disrupting the normal signals to the pituitary gland.

HPO Axis Suppression: As a result of the suppressed GnRH release, the pituitary gland releases fewer FSH and LH hormones. With reduced levels of these hormones, the ovaries may not function properly, leading to disruptions in the menstrual cycle and, in some cases, amenorrhea.

The Female Athlete Triad

Amenorrhea often doesn't happen on its own in female athletes. It's often part of something called the Female Athlete Triad. This triad consists of three interconnected problems: menstrual dysfunction (like amenorrhea), low energy availability (not getting enough calories), and decreased bone mineral density.

The menstrual dysfunction is a sign that your body might not be getting what it needs to function properly. Low energy availability means your body is burning more energy than it's taking in, which can be harmful in the long run. Lastly, decreased bone mineral density means that your bones might become weaker and more prone to injuries.

Disordered Eating

It is important to note that the lack of energy in the Female Athlete Triad is with or without an eating disorder. Eating disorders can be quite common in female athletes, but even those without eating disorders but are training at a high level can experience this energy imbalance. Disordered eating can include a range of irregular eating behaviours, even ones that do not meet criteria for severe eating disorders such as anorexia nervosa or bulimia nervosa, which are fairly common in the female athletic community. Additionally, this triad is more common in women who partake in sports that emphasize leanness or aesthetics, such as ballet or running.

Why It Matters

You might wonder why these issues matter so much. After all, aren't athletes supposed to push themselves to the limit? While it's true that athletes aim for peak performance, the Female Athlete Triad can have serious consequences if left unaddressed. Not only can it affect your athletic performance, but it can also lead to long-term health problems like weakened bones, a higher risk of fractures, and reproductive health issues. Prevention of eating disorders and promoting a positive mind set with body image are also very important.

Estrogen and Bone Health

Beyond menstrual cycles and reproductive health, estrogen plays a crucial role in bone health. As mentioned above, the Female Athlete Triad can also lead to long-term health problems like weakened bones and a higher risk of fractures. This is due to suppression of the HPO axis and estrogen.

 Bone Density Maintenance: Estrogen helps in maintaining and increasing bone density. It does this by promoting the activity of bone-forming cells called osteoblasts. This action is vital for overall bone strength and resistance to fractures.

Inhibition of Bone Resorption: Estrogen acts as a natural inhibitor of bone resorption, the process by which bone tissue is broken down and absorbed back into the body. This inhibition helps to preserve the existing bone mass and structure. 

Prevention of Osteoporosis: Postmenopausal women, who experience a significant reduction in estrogen levels, are at a higher risk of developing osteoporosis. Osteoporosis is a condition characterized by weak and fragile bones, making them more susceptible to fractures. By maintaining estrogen levels, the risk of osteoporosis is reduced.

Promotion of Calcium Absorption: Estrogen indirectly promotes calcium absorption in the intestines, which is essential for bone health. Adequate calcium is necessary for building and maintaining strong bones.

 Supporting Growth Plates in Adolescence: During adolescence, estrogen is involved in the growth process. It helps the growth plates at the ends of long bones to close at an appropriate time. Proper closure of the growth plates ensures that bones reach their optimal size and shape.

Collagen Production: Estrogen also supports collagen production in bones. Collagen provides the structural framework for bones and contributes to their flexibility and tensile strength.

Overall Skeletal Health: Beyond its direct effects on bone cells, estrogen has a broader impact on overall skeletal health. It helps to maintain the balance between bone formation and bone resorption, ensuring that the skeleton remains strong and structurally sound.

Prevention of Fractures: Low estrogen levels, such as those experienced during menopause, are associated with an increased risk of fractures, particularly in the spine, hip, and wrist. Maintaining estrogen levels, either through hormone replacement therapy or lifestyle choices, can reduce this risk.

Regulation of Bone Turnover: Estrogen is involved in regulating the process of bone turnover, which is the continuous renewal of bone tissue. Proper regulation of this turnover ensures that bones stay healthy and functional.

Stay tuned for Understanding the Female Athlete Triad and Amenorrhea: Part 2 to learn how to best seek help, as well as to prevent and treat the Female Athlete Triad.