Understanding Relative Energy Deficiency in Sport (RED-S)

In the world of sports, athletes are often celebrated for their incredible physical abilities and dedication to their craft. However, behind the scenes, many face a hidden struggle known as Relative Energy Deficiency in Sport (RED-S). This condition can have profound implications on an athlete's performance, health, and overall well-being. 

What is RED-S?

Relative Energy Deficiency in Sport (RED-S) refers to a state where an athlete does not consume enough energy (calories) to support their daily bodily functions and training requirements. This energy imbalance can lead to numerous physiological and psychological issues, affecting various systems, including hormonal balance, metabolism, immune function, and bone health.

Previously referred to as the "Female Athlete Triad", RED-S was introduced in 2014 as a broader term to encompass the consequences of energy deficiency not only related to eating disorders and women, but also as a lifestyle choice or from misconceptions about nutrition and training demands.

Symptoms of RED-S

The symptoms of RED-S can be diverse and may not always be straightforward. Common signs include:

  • Fatigue: A persistent feeling of tiredness that doesn’t improve with rest.
  • Menstrual Irregularities: For female athletes, missed periods or irregular cycles can be a significant indicator.
  • Frequent Injuries: Increased risk of stress fractures and other injuries due to weakened bone health.
  • Decreased Performance: A noticeable drop in strength, endurance, or overall athletic performance.
  • Mood Changes: Heightened anxiety, irritability, or depression can also manifest in athletes suffering from energy deficiency.
  • Digestive Issues: Problems such as bloating, constipation, or discomfort can arise.

Causes of RED-S

Several factors contribute to the development of RED-S:

  1. Inadequate Caloric Intake: Athletes may not consume enough food due to strict dieting, a lack of understanding of energy demands, or peer pressure.

  2. Increased Training Demands: Athletes often train intensely and may not increase their caloric intake to match their energy expenditure.

  3. Misconceptions about Weight and Performance: Some athletes may believe that being lighter will improve their performance, leading to unintentional under-eating.

  4. Cultural and Societal Pressure: The pressure to conform to certain body ideals can lead to unhealthy eating patterns.

Prevention and Treatment

Awareness and education are crucial in preventing RED-S. Athletes, coaches, and support staff should be educated about the importance of energy balance. Here are some effective strategies:

  • Balanced Nutrition: Athletes should focus on a well-rounded diet that meets their energy needs, including all macronutrients (carbohydrates, proteins, and fats).

  • Regular Monitoring: Health professionals should monitor athletes’ weight, menstrual health, and energy levels regularly to detect early signs of RED-S.

  • Communication: Creating an environment where athletes feel comfortable discussing their nutrition and mental health is essential for early intervention.

  • Professional Guidance: Working with sports dietitians and mental health professionals can provide athletes with personalized support in developing a healthy relationship with food and training.


Relative Energy Deficiency in Sport (RED-S) is a serious condition that can affect any athlete, regardless of their sport or level of competition. Understanding its symptoms and causes is the first step towards prevention and treatment. Athletes must learn the importance of energy balance and seek support when needed. Ultimately, a healthy athlete is not just measured by their performance but also by their overall physical and mental well-being.