GLOSSARY

RED-S Management Coordinated care addressing energy supply, training, medical concerns and psychological factors relevant to RED-S.

Relative energy deficiency in sport describes impaired health or function associated with problematic low energy availability and can affect female and male athletes. The duration, severity and individual context matter. No isolated body weight, symptom, hormone value or calculated energy-availability threshold can diagnose every case. Clinical assessment integrates history, signs, measurements and alternative explanations. The IOC assessment framework supports trained clinicians; it is not a self-scoring clearance tool. Management addresses energy supply and training while considering psychological support and the athlete's overall safety.

Energy availability describes dietary energy remaining after exercise expenditure, expressed relative to fat-free mass over a defined period. It differs from whole-day energy balance and from body-fat percentage. Calculations are sensitive to errors in food records, exercise expenditure and body-composition estimates. No single threshold or short observation establishes a diagnosis for every athlete. Persistent fatigue, impaired recovery or other concerning changes warrant assessment in the broader health and training context rather than a conclusion from one calculated value.

Menstrual dysfunction is a clinical signal with several possible causes, including pregnancy, endocrine disorders, medication and inadequate energy availability. Functional hypothalamic amenorrhea is diagnosed after appropriate evaluation, not from training volume alone. Missing periods should not be normalized as an inevitable sign of serious training. Withdrawal bleeding on hormonal contraception does not establish recovery of spontaneous menstrual function. A qualified team should assess the history, energy supply, bone health and other causes while coordinating nutrition, medical care and training decisions.