Description

• Relative energy deficiency in sport (RED-S) (female athlete triad) first described in 1992 to include DE, amenorrhea, and osteoporosis
• In 2007, American College of Sports Medicine (ACSM) updated definition to: components including LEA (with or without DE), MD, and LBMD with each component representing an interrelated spectrum ranging from health to dysfunction.
• LEA is fundamental to RED-S and full recovery is not possible without correction of it.
• 2014 International Olympic Committee’s (IOC) position statement from 2014 deviated to consider “RED-S.”
  • Focus on energy deficiency and its broader physiologic effects beyond bone and menstrual health, ranging from growth to cardiovascular.
  • Emphasized similar syndrome in males
• Male athlete triad; LEA, functional hypothalamic hypogonadism, and LBMD
• Concept of energy deficiency in men involving reproductive and bone abnormalities

Epidemiology

Etiology and Pathophysiology

• EA is defined by energy intake minus exercise energy expenditure.
  • LEA can occur either intentionally or inadvertently (e.g., increasing training or DE).
  • Results in energy shunted from reproduction to more critical functions, (thermoregulation cellular maintenance)
  • Leads to suppression of luteinizing hormone (LH) pulse frequency and thus MD
    • This suppresses ovulation and estrogen concentrations, causing decreased bone formation and increased bone resorption, leading to LBMD.
• RED-S elements exist along a bidirectional continuum of severity, ranging from “healthy” to “unhealthy.”
• Additionally, LEA effects endothelial dysfunction and lipids.

Risk Factor

• History of menstrual irregularities and amenorrhea; stress fractures and recurrent or nonhealing injuries; critical comments about eating or weight from parent or coach; depression; dieting; personality factors (perfectionism and/or obsessiveness), overtraining, and inappropriate coaching behaviors
• Lean physique sports with an aesthetic component (ballet, figure skating, gymnastics), or sports with weight classifications (wrestling); frequent weigh-ins, consequences for weight gain, and win-at-all-cost attitude all increase risk.
• A lack of family or social support; intense training hours; social isolation, or entering a new environment (boarding school or college); an athlete with comorbid psychological conditions (anxiety, depression, and/or obsessive-compulsive disorder)

General Prevention

• Education of athletes, coaches, trainers, parents, and physicians. Young athletes are extremely impressionable and may turn negative comments and unhealthy advice into maladaptive eating and exercising habits.
• General screening during preparticipation exam (PPE) and annual physicals
• Female Athlete Triad Coalition has 11-question screening to use during PPE.
• Screen athletes presenting with “red flag” conditions such as fractures, weight changes, fatigue, amenorrhea, bradycardia, orthostatic hypotension, syncope, arrhythmias, electrolyte abnormalities, or depression.
• Screen for other conditions that may accelerate bone loss, including steroid use, tobacco use, alcohol use, and hyperthyroidism.
• IOC consensus statement (2023) recommends only testing body composition in athletes <18 years of age for medical purposes due to risk of detrimental medical and psychological outcomes with unnecessary testing (1).

Commonly Associated Conditions

• Anorexia nervosa, bulimia nervosa, avoidant or restrictive food intake disorder, and other psychological disorders, including low self-esteem, depression, and anxiety
• LBMD predisposes athletes to stress fractures and may not be fully reversible. This may lead to a higher rate of fractures after menopause.