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Relative Energy Deficiency in Sport (RED-S)

Relative Energy Deficiency in Sport (RED-S), is a syndrome which can adversely affect the health and performance of athletes.  It exists when there is a negative balance between dietary energy intake and the energy expenditure required to support optimal health, daily living activities, growth, and sport.

Key messages

What is REDs

RED-S is caused by low energy availability and can have long-term health impacts for both women and men.


It is most prevalent in sports/activities where leanness/weight are important for performance; aesthetics/appearance; or to meet a weight category.

Diagnosis and treatment

Diagnosis and treatment of RED-S should be completed by a team of medical specialists.

RED-S is most common in sports where leanness and/or weight are important for performance (long distance running, road cycling); aesthetics/appearance (gymnastics, dancing); or to meet a weight category (wrestling, boxing, combat sports).

Screening for RED-S can be difficult as the symptoms can be quite subtle. Athletes, parents, coaches, and medical practitioners need to understand the signs, symptoms, and dangers of RED-S in order to identify athletes who are in danger of developing, or already have, the syndrome and to determine an appropriate treatment.

As the primary cause of RED-S is energy deficiency some early signs can be:

  • weight loss;
  • Disordered Eating (DE) or an Eating Disorder (ED);
  • lack of normal growth and development;
  • menstrual dysfunction;
  • recurrent injuries and illnesses;
  • decreased performance; or
  • mood or social behavioural changes.

Coaches who observe such signs should refer their athlete to a medical professional for diagnosis and treatment.

Key areas of research

Related Topics

Reviewed by: Australasian Sport Information Network
Last updated: 13 October 2020
Content disclaimer: See Clearinghouse for Sport disclaimer

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