The cessation of menstruation, known as amenorrhea, in female athletes is a serious physiological red flag, not a sign of peak fitness. This phenomenon, which is common in high-demand sports like gymnastics, signals that the body is under profound metabolic stress. The absence of a period indicates the body has initiated a survival mechanism, diverting energy away from reproductive function to support immediate needs. The underlying problem is not low body fat, but a severe and chronic energy imbalance that carries significant short- and long-term health consequences.
The Role of Low Energy Availability
The root cause of menstrual disruption in gymnasts is Relative Energy Deficiency in Sport (RED-S), which replaced the older term “Female Athlete Triad.” RED-S describes a state where dietary energy intake is insufficient to cover the energy expended during daily life and intense training, creating a substantial energy gap. This deficit is called low energy availability (LEA).
Gymnastics is susceptible to RED-S due to high training volume, pressure to maintain a lean aesthetic, and a culture that promotes under-fueling. Training 20 or more hours per week requires high caloric intake; if the diet does not match this expenditure, the body enters a state of perceived starvation. It is forced to compromise non-essential functions to conserve limited energy stores.
The issue is the calorie deficit, or energy balance, that triggers the body’s adaptive responses, not simply being thin. LEA can occur even if an athlete consumes a seemingly normal amount of calories if their training load is extreme. The body interprets this lack of energy as a threat to survival, initiating hormonal changes across multiple systems, including the reproductive axis.
How Training Disrupts the Menstrual Cycle
The physiological mechanism that halts menstruation begins with the suppression of the Hypothalamic-Pituitary-Ovarian (HPO) axis in the brain. The hypothalamus detects low energy availability and interprets it as stress or famine. The brain responds by slowing the pulsatile release of Gonadotropin-releasing Hormone (GnRH).
Reduced GnRH signaling causes a subsequent drop in the pituitary hormones, Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH). Since LH and FSH stimulate the ovaries to produce estrogen and progesterone, their suppression leads to hypoestrogenism (low estrogen). Without sufficient estrogen and progesterone, the cyclical hormonal signals required for the uterine lining are absent, resulting in functional hypothalamic amenorrhea.
This hormonal shutdown temporarily pauses energy-intensive processes like reproduction. The suppression of the HPO axis is often accompanied by an increase in the stress hormone cortisol, indicating the body is in a state of high physiological duress. The missing period is a clear physical symptom of this internal energy crisis.
The Impact on Skeletal Health
One severe long-term consequence of athletic amenorrhea is the negative impact on bone health, directly linked to prolonged low estrogen. Estrogen plays a role in skeletal homeostasis, maintaining the balance between bone formation and bone resorption. By inhibiting osteoclasts (the cells that break down bone) and promoting osteoblasts (the cells that build bone), estrogen is essential for strong, dense bones.
When estrogen levels are chronically low, this protective effect is lost, leading to a decrease in bone mineral density (BMD). This reduction in bone mass is particularly concerning for adolescent gymnasts, as peak bone mass accretion—up to 50% of total bone mass—occurs during the years between 12 and 18. Disruption of this process can result in a permanent failure to reach maximum bone density.
The resulting low BMD significantly increases the risk of bone stress injuries, such as stress reactions and stress fractures. Athletes with amenorrhea are estimated to be two to four times more likely to suffer a stress fracture than those with normal menstrual cycles. Prolonged hypoestrogenism and bone density loss in youth also raise the risk of developing premature osteoporosis later in life.
Pathways to Recovery
The primary goal for recovery is to address the underlying energy deficit and restore the body’s natural hormonal function. Simply masking the problem with hormonal birth control is generally not recommended. It provides synthetic hormones that cause withdrawal bleeding but does not fix the fundamental energy imbalance or restore the HPO axis. Oral estrogen may also not provide the same bone-building benefits as natural estrogen.
The solution requires a two-pronged approach: increasing energy intake and decreasing energy expenditure. Athletes are advised to increase daily caloric intake, focusing on nutrient-dense foods, including healthy fats and carbohydrates, to provide the energy their body needs. A targeted increase of 300 to 600 calories per day is often the first step in treatment.
Temporarily reducing the intensity, frequency, or duration of training is necessary to reduce total energy burned. Seeking guidance from a specialized medical team, including a sports nutritionist and an endocrinologist, is crucial for a personalized plan. The return of a natural menstrual cycle is the clearest sign that energy balance has been restored, signaling that the body is healthy enough to support all physiological functions.