IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update

To investigate the dependence of LH pulsatility on energy availability (dietary energy intake minus exercise energy expenditure), we measured LH pulsatility after manipulating the energy availability of 29 regularly menstruating, habitually sedentary, young women of normal body composition for 5 d in the early follicular phase. Subjects expended 15 kcal/kg of lean body mass (LBM) per day in supervised exercise at 70% of aerobic capacity while consuming a clinical dietary product to set energy availability at 45 and either 10, 20, or 30 kcal/kg LBM.d in two randomized trials separated by at least 2 months. Blood was sampled daily during treatments and at 10-min intervals for the next 24 h. Samples were assayed for LH, FSH, estradiol (E2), glucose, beta-hydroxybutyrate, insulin, cortisol, GH, IGF-I, IGF-I binding protein (IGFBP)-1, IGFBP-3, leptin, and T3. LH pulsatility was unaffected by an energy availability of 30 kcal/kg LBM.d (P > 0.3), but below this threshold LH pulse frequency decreased, whereas LH pulse amplitude increased (all P < 0.04). This disruption was more extreme in women with short luteal phases (P < 0.01). These incremental effects most closely resembled the effects of energy availability on plasma glucose, beta-hydroxybutyrate, GH, and cortisol and contrasted with the dependencies displayed by the other metabolic hormones (simultaneously P < 0.05). These results demonstrate that LH pulsatility is disrupted only below a threshold of energy availability deep into negative energy balance and suggest priorities for future investigations into the mechanism that mediates the nonlinear dependence of LH pulsatility on energy availability.

The Female Athlete Triad is a medical condition often observed in physically active girls and women, and involves three components: (1) low energy availability with or without disordered eating, (2) menstrual dysfunction and (3) low bone mineral density. Female athletes often present with one or more of the three Triad components, and an early intervention is essential to prevent its progression to serious endpoints that include clinical eating disorders, amenorrhoea and osteoporosis. This consensus statement represents a set of recommendations developed following the 1st (San Francisco, California, USA) and 2nd (Indianapolis, Indiana, USA) International Symposia on the Female Athlete Triad. It is intended to provide clinical guidelines for physicians, athletic trainers and other healthcare providers for the screening, diagnosis and treatment of the Female Athlete Triad and to provide clear recommendations for return to play. The 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad expert panel has proposed a risk stratification point system that takes into account magnitude of risk to assist the physician in decision-making regarding sport participation, clearance and return to play. Guidelines are offered for clearance categories, management by a multidisciplinary team and implementation of treatment contracts. This consensus paper has been endorsed by the Female Athlete Triad Coalition, an International Consortium of leading Triad researchers, physicians and other healthcare professionals, the American College of Sports Medicine and the American Medical Society for Sports Medicine.