Relative Energy Deficiency in Sport (RED-S): Scientific, Clinical, and Practical Implications for the Female Athlete

If athletes develop low energy availability (LEA), it can lead to a Relative Energy Deficiency in Sport (RED-S) syndrome which has severe health consequences if not treated.

A narrative review of the most recent and pertinent literature on the topic, with special emphasis on women.

In assessing the current literature, we have synthesized: i) the scientific implications of LEA and RED-S, ii) the clinical manifestations of the conditions currently available for detection, as well as iii) the practical implications for healthcare and support for female athletes and teams in planning intervention or prevention strategies (maintaining EA >45 kcal/kg FFM/day).

The 'Female Athlete Triad" emerged in the 1990s as researchers understood more of the etiological adaptation of female athlete health to sports training. In the last 10 years, the scientific community has recognized that the 'Triad' approach was too narrow in focus, and the broader concept of RED-S emerged. Both the Triad and RED-S are consequences of a frequently prevalent LEA in athletes (<30 kcal/kg FFM/day). Developing LEA and RED-S compromises training adaptation, performance capacity, and health in athletes. For these reasons, it is critical that an athlete's support team recognize the behaviors that may indicate RED-S evolution. In this way, we can assist female athletes in reaching their full potential in sports while protecting their health.