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In recent years, more and more attention has been paid to specific women's health problems and diseases in sports. Since the pressure for results in women's sport is enormous, and since it is becoming increasingly difficult to succeed in competition, women are increasingly exposed to some of the negative impacts of elite sport. 

In the last two decades, a female specific health disease in sport called the female athlete triad has become well known. In 2014 the International Olympic Committee advanced the concept of the female athlete triad with the term relative energy deficiency in sport (RED-S). RED-S covers the broader consequences of chronic low energy availability on an athlete’s health and performance.

It also recognizes the fact that any athlete, regardless of sex or gender, can experience this syndrome. The female athlete triad is a more specific and traditional term that describes three interrelated conditions: disordered eating, irregular menstruation, and bone loss. RED-S refers to more complex impairment of physiological functioning caused by relative energy deficiency and includes, but is not limited to, impairments of metabolic rate, menstrual function, bone health, immunity, protein synthesis and cardiovascular health.


RED-S is a condition that occurs when athletes, both male and female, do not consume enough calories to meet the energy demands of their training and competition. However, the term "Female Athlete Triad" has historically been used to describe a similar condition that primarily affects female athletes, which includes low energy availability, menstrual dysfunction, and low bone density.  The key factor of the two conditions is low energy availability. 

Low energy availability is described as a state in which the body does not have enough energy to support all the physiological functions needed to maintain optimal health. This condition can occur in both male and female athletes, as well as non-athletes, and can lead to a range of health problems. Practically, low energy availability is something that athletes can experience after a particularly demanding training session or competition. With rest and hearty nutritious meals, most athletes can replenish their energy reserves and continue training and competing in a healthy way. Low energy availability can be caused by a variety of factors, including insufficient caloric intake, excessive physical activity, or a combination of both. When the body is in a state of low energy availability, it is forced to conserve energy by reducing metabolic rate which can lead to a range of physiological and psychological problems. If an athlete continues to push themselves without refueling, the energy deficit will deepen and over time can negatively affect not just their sports performance but also their health and well-being. It is important to address low energy availability promptly to prevent long-term health consequences. 


RED-S and female athletes triad reproduced from Mountjoy et al.  2014


  • Decreased athletic performance: RED-S can negatively affect athletic performance, including decreased strength, endurance, and speed.
  • Low energy levels: Athletes may feel tired, fatigued, or sluggish, even when they are not exercising.
  • Fatigue: Athletes may experience excessive fatigue and feel drained, even with adequate rest.
  • Irregular menstrual cycles or amenorrhea: Female athletes may experience changes in their menstrual cycle, including missed periods, irregular periods, or a complete cessation of periods
  • Weight loss or difficulty gaining weight: Athletes may experience unexplained weight loss or have difficulty gaining weight, despite eating a normal or increased amount of food.
  • Decreased muscle mass: Athletes with RED-S may experience a loss of muscle mass, which can negatively impact their strength and power.
  • Decreased immune function: Athletes may be more susceptible to infections and illnesses because their immune function is compromised.
  • Decreased bone density: RED-S can lead to decreased bone density, which can increase the risk of stress fractures and other bone injuries.
  • Psychological effects: RED-S can affect a person's mood, leading to depression, anxiety, and irritability.


RED-S can have serious consequences for athletes, including decreased athletic performance, increased risk of injury, and long-term health problems such as infertility, osteoporosis, and cardiovascular disease. It is important to note that RED-S can affect athletes in any sport, regardless of their body size or shape. RED-S can have serious consequences for health and athletic performance. RED-S can be challenging to diagnose because the symptoms can be subtle and can overlap with other conditions. However, there are some signs and symptoms that athletes, coaches, and healthcare professionals should be aware of. If an athlete shows any of these signs, it is important to seek medical attention and consider the possibility of RED-S. A healthcare professional can help diagnose and treat the condition to prevent long-term health consequences.



  • Medical history: The healthcare professional will take a detailed medical history, including information about the athlete's training and competition history, nutrition and eating habits, menstrual history (for female athletes), and any symptoms that may be associated with RED-S.
  • Physical exam: The healthcare professional will perform a physical exam to assess the athlete's overall health and look for any signs of RED-S, such as low body weight, decreased muscle mass, and decreased bone density.
  • Laboratory tests: The healthcare professional may order laboratory tests to assess the athlete's hormone levels, bone density, and overall health. These tests may include blood tests, such as a complete blood count, thyroid function tests, and sex hormone levels. Imaging tests, such as a DXA scan or bone density scan, may also be ordered to assess bone health.
  • Evaluation of energy availability: Energy availability, which is the amount of energy left over after training for use in normal body functions, is a key component of RED-S. A healthcare professional may use a combination of dietary assessment and metabolic testing to evaluate energy availability in athletes.


Prevention of RED-S requires a comprehensive approach that addresses nutrition, training, and overall health. Also, the prevention of RED-S requires a collaborative effort among athletes, coaches, trainers, and healthcare professionals. By prioritizing proper nutrition and overall health, athletes can maximize their performance, and reduce their risk of RED-S and other negative effects on health.

The strategy of prevention or early treatment of RED-s can be divided into the following categories: 

  • Adequate energy intake: Athletes need to consume enough calories to meet the energy demands of their training and competition. This means that they need to eat enough to maintain a healthy body weight and support their training goals.
  • Balanced diet: Athletes should prioritize nutrient-dense foods, such as fruits, vegetables, whole grains, lean proteins, and healthy fats. They should also aim to consume a variety of foods to ensure they are getting all the nutrients they need.
  • Training: Coaches and trainers should work with athletes to develop a training plan that supports their individual needs and goals while ensuring adequate rest and recovery. Overtraining and inadequate rest/recovery can contribute to the development of RED-S.
  • Monitoring: Regular monitoring of nutrition, body weight, menstrual function (for female athletes), and bone density is essential for early detection and prevention of RED-S. This can be done by athletes themselves, parents, coaches as well as healthcare professionals.
  • Education: Athletes, coaches, and parents should be educated about the risks and consequences of RED-S. Education should focus on the importance of proper nutrition, energy balance, and rest/recovery to support optimal sports performance and reduce the risk of RED-S, as well as other negative effects on health.
  • Positive team environment: Coaches and teams can promote a positive and supportive team environment that prioritizes health, wellness, and performance over weight and appearance.
  • Mental health: Psychological factors, such as stress, anxiety, and body image concerns, can contribute to the development of RED-S. Athletes should prioritize their mental health and seek support from a mental health professional if needed.
  • Early intervention: If an athlete shows signs of RED-S, such as changes in menstrual function or decreased performance, it is important to intervene early to prevent the condition from worsening.


Tip: Nutrition: Athletes or teams should work with a registered dietitian to develop an individualized nutrition plan that meets their energy needs and supports their training and competition goals. The dietitian may also provide guidance on proper timing of meals and snacks to optimize energy availability.



The female athlete triad as a part of RED-S is an interrelationship of low energy availability (with or without an eating disorder), menstrual dysfunction, and decreased bone mineral density; and is relatively common among young women in sport. These three conditions can occur independently, but they often occur together in sports that emphasize leanness or require high levels of training and performance. The female athlete triad is a serious condition that can have long-term health consequences if left untreated. Female athletes who are at risk for the triad should work with a healthcare provider and a sports nutritionist to develop a healthy eating plan and training regimen that meets their individual needs while also promoting overall health and well-being. It is important to address the triad early to prevent long-term complications such as stress fractures, infertility, and osteoporosis.



The female athlete triad is caused by a combination of factors related to nutrition, hormones, and physical activity. The specific causes of the triad are not fully understood, but there are several factors that can contribute to its development:

  • Caloric restriction: Athletes who restrict their caloric intake, either intentionally or unintentionally, may not consume enough energy to meet the demands of their sport. This can lead to weight loss and a decrease in body fat, which can disrupt the menstrual cycle and lead to a decrease in bone density.
  • Overtraining: Regular and long-term intense training without appropriate recovery can place stress on the body and cause hormonal imbalances. 
  • Genetics: Some females may be predisposed to developing the triad due to genetic factors that affect bone density and hormonal regulation.
  • Psychological factors: Anxiety, depression, and low self-esteem can contribute to the development of disordered eating behaviors, which can in turn contribute to development of the triad.

More detail into the three conditions of the female athlete triad (energy deficiency, menstrual irregularities, and decreased bone density) is below. 

Energy deficiency 

Energy deficiency refers to a state in which an individual's energy intake is insufficient to meet their energy needs. Energy deficiency can occur for a variety of reasons, including inadequate food intake, increased energy expenditure due to physical activity or illness, and certain medical conditions that interfere with the body's ability to absorb or utilize nutrients. Energy deficiency, also known as low energy availability, means that the body does not have enough energy for training or for maintaining health.  A major cause of energy deficiency is disordered eating. This can include binge eating, crash diets, and/or restricting nutrient intake. These eating disorders, in combination with high training demands, can result in more severe or prolonged cases of disordered eating. Abnormal eating behaviors can evolve into clinical eating disorders (such as anorexia or bulimia), distorted body images, and further medical complications.

Menstrual dysfunction 

The menstrual cycle is a physiological process that involves changes in the reproductive organs and hormones to prepare for potential pregnancy. The menstrual cycle typically lasts for 23–28 days, but duration varies from person to person. The menstrual cycle is made up of three phases of hormonal fluctuation: the follicular phase (low estrogen, low progesterone levels), the ovulatory phase (high estrogen, low progesterone levels), and the mid-luteal phase (high estrogen and progesterone levels). Typically, the effects of estrogen and progesterone are examined at the level of the uterus; however estrogen and progesterone also have effects on multiple organ systems which may affect female athletic performance. 

Changes in hormone levels during the menstrual cycle can cause a range of physical and emotional symptoms, such as bloating, cramping, mood swings, and headaches. It is important for individuals to track their menstrual cycle to better understand their own patterns and to detect any potential irregularities that may require medical attention. Poor nutrition, energy deficiency, high-energy demands, physical and emotional stress, and/or a low percentage of body fat can all lead to hormonal changes resulting in irregular menses or the cessation of menstrual periods altogether (amenorrhea).

Low bone mineral density 

Lack of periods disrupts the body's bone-building processes and weakens the skeleton, making bones more likely to break.  In the most severe cases, young athletes can develop osteoporosis because of disordered eating and menstrual dysfunction. 

There are also several factors which can increase the risk of developing female athlete triad: 

  • Early specialization in sport: Athletes who specialize in one sport at a young age and engage in high-intensity training for many hours a week may be at increased risk.
  • Inappropriately high training volume: Athletes who train for long periods of time or engage in intense training sessions multiple times per day may be at increased risk.
  • Genetics: There may be genetic factors that predispose some individuals to the triad, such as low bone density or hormonal imbalances.
  • Hormonal imbalances: Changes in hormones, such as estrogen and progesterone, can contribute to the development of the triad.
  • History of menstrual irregularities: A history of menstrual irregularities or missed periods can increase the risk of developing the triad.
  • Disordered eating behaviors: Athletes who engage in disordered eating behaviors, such as skipping meals, restricting calories, or purging, may be at increased risk.
  • Psychological stress: Psychological stress can also be a risk factor for the triad. Factors such as low self-esteem, anxiety, or depression may contribute to disordered eating behaviors.



The treatment must be approached in a multidisciplinary way which includes physical therapists, nutritionists, and psychologists/psychiatrists. Treatments will be specific for each component of the triad. Coaches, parents, health care professionals, and fellow teammates should be aware of these signs and symptoms and discuss any concerns with the athlete privately.

Prevention should be the most important aspect, considering the serious short and long-term consequences. One of the most important preventative measures is education of athletes, coaches, and parents.  Emphasis should be placed on optimizing energy availability. It is important to understand the risk of impaired bone mineral density, reduced done mineral density, osteoporosis, stress fractures. 


There are things you can do to prevent female athletes’ triad, especially if someone is at risk: 

  • Adequate caloric intake: It is important for athletes to consume enough calories to meet the energy demands of their sport and to maintain a healthy body weight. Working with a sports nutritionist can help ensure that an athlete is getting the proper nutrients to fuel their body.
  • Balanced training: Athletes should engage in a balanced training program that includes on water and off water trainings and rest/recovery. This can help prevent overreaching and overtraining syndrome as well as reduce the risk of hormonal imbalances.
  • Regular menstrual cycles: A regular menstrual cycle is a sign of overall hormonal health. If an athlete experiences irregular periods or missed periods, it is important to seek medical attention.
  • Body positivity: Emphasizing body positivity and self-acceptance can help prevent the development of disordered eating behaviors and promote overall mental well-being.
  • Mental health support: Addressing any underlying psychological issues, such as anxiety or depression, can help prevent the development of disordered eating behaviors and promote overall mental well-being.
  • Medical evaluation: Regular medical check-ups, including bone density scans and blood tests, can help identify any early signs of the triad and allow for early intervention and treatment.


Based on the evidence, we conclude that the female athlete triad can cause long-term damage to health. It can also hurt sports performance or make it necessary to limit or stop training. For these reasons, it is important to educate athletes and coaches about the possible negative impacts of the triad—not just for sports performance, but also for general health and quality of life.


Written by Matej Vajda

Reviewed by Jaylene Pratt



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