RELATIVE ENERGY DEFICIENCY IN SPORT (RED-S/REDs) IN ATHLETES: A NARRATIVE REVIEW OF CLINICAL CONSEQUENCES, SCREENING, PREVENTION, AND DIGITAL HEALTH IMPLICATIONS

Abstract

Relative Energy Deficiency in Sport (REDs) is a clinical syndrome resulting from problematic low energy availability and associated with impaired physiological and psychological functioning in athletes. This narrative review synthesizes current evidence on the conceptual development of REDs, its multisystem consequences, screening and diagnosis, prevention, management, return-to-play considerations, and digital health implications. Literature was reviewed thematically, with priority given to International Olympic Committee consensus statements, clinical assessment tools, narrative and systematic reviews, and studies addressing low energy availability, endocrine and bone health, mental health, male and adolescent athletes, and athlete monitoring. Current evidence indicates that REDs may affect reproductive, skeletal, endocrine, metabolic, immunological, gastrointestinal, cardiovascular, hematological, psychological, and performance-related domains. Diagnosis remains challenging because symptoms are often nonspecific and no single biomarker confirms the condition. Assessment should therefore combine medical history, training load, nutritional intake, reproductive and bone health indicators, psychological screening, laboratory and imaging findings when indicated, and structured tools such as the IOC REDs CAT2. Management should focus on restoring adequate energy availability, adapting training load, treating medical complications, and providing psychological support when needed. Prevention requires coordinated action from athletes, coaches, parents, clinicians, and sport organizations. Digital tools may support early identification, but only when implemented within confidential, ethical, and athlete-centered systems.