II. Definitions
- Relative Energy Deficiency in Sport (RED-S)
- Relative energy deficiency
- Results in impaired physiologic functioning
- Impaired metabolic rate, Protein synthesis
- Amenorrhea or Oligomenorrhea
- Impaired cardiovascular health
- Low Bone Mineral Density
III. Background
-
Female Athlete Triad was originally defined by American College of Sports Medicine (1984)
- Disordered Eating
- Amenorrhea
- Premature Osteoporosis
- International Olympic Committee renamed Female Athlete Triad as RED-S (2014)
- Relative energy deficiency
- Results in impaired physiologic functioning affecting multiple systems beyond original definition
- Impaired metabolic rate, Protein synthesis
- Amenorrhea or Oligomenorrhea
- Impaired cardiovascular health
- Low Bone Mineral Density
- Associated with multi-system complications
- See below
IV. Epidemiology
- More common in female gender, but also occurs in males
V. Risk Factors
- Eating Disorder (e.g. Anorexia Nervosa)
- Sport type
- Judged sports (appearance, aesthetics)
- Weight category sports
- Endurance sports
VI. Pathophysiology
- Low energy availability
- Dietary Energy Intake is insufficient for Energy Expenditure needs (given sports activity)
VII. Evaluation: Screening
- Low Energy Availability in Females Questionnaire (LEAF-Q)
- RED-S Low Risk Criteria (Green)
- Appropriate BMI and body habitus
- Appropriate energy availability and healthy eating
- Normal cardiovascular exam
- Normal mood and affect
- Normal Menstrual Cycles (may be altered by contraceptives)
- Healthy bone density for cohort (Z-Score) without recurrent Stress Fractures
- Healthy musculoskeletal system without frequent or persistent injury
- RED-S Moderate Risk Criteria (Yellow)
- Significant recent weight loss (5 to 10% of BMI) or prolonged low BMI
- Low energy availability or disordered eating that is severe or prolonged
- Associated physical complications of disordered eating
- Abnormal Menstrual Cycle
- No Menarche by age 15 years
- Functional Hypothalamic Amenorrhea >3 months
- Stress Fractures (at least one) due to endocrine dysfunction or low energy availability
- Decreased bone density by DEXA Scan (Z-Score <1 S.D. or decreased from prior)
- Disordered eating refractory to management or impacting other team members
- RED-S High Risk Criteria (Red)
- Anorexia Nervosa or other serious condition related to low energy availability
- Extreme weight loss techniques
VIII. Signs
- Decreased glycogen stores
- Decreased Motor Strength
- Decreased endurance Exercise performance
- Increased Musculoskeletal Injury risk
- Fatigue and difficult recovery from Exercise
- Impaired concentration, judgement and coordination
- Increased irritability and depressed mood
IX. Differential Diagnosis
- Endocrine abnormalities (e.g. Hypothyroidism, Adrenal Insufficiency)
- Female Athlete Triad (similar syndrome with overlapping definition, preceded RED-S Definition)
- Eating Disorder
X. Management
- Multi-disciplinary team
- Sports medicine provider
- Sports dietician and nutritionist
- Sports psychologist
- Goals
- Restore balance between Caloric Intake and expenditure
- Treatment Plan (expectations for continued sports participation)
- Regular follow-up
- Meal Plan adherence
- Individualized weight gain plan adherence
- Return-To-Play
- RED-S Low Risk (Green)
- Full sports participation without restriction
- RED-S Moderate Risk (Yellow)
- May continue to train as long as following above treatment plan
- May compete under supervision if medically cleared
- RED-S High Risk (Red)
- No competition or training
- Follow treatment plan as above (under a written contract signed by patient)
- Adherence to a minimum BMI
- RED-S Low Risk (Green)
- Other measures
- Antidepressant use is limited to typical indications for psychiatric conditions (e.g. Major Depression)
- Oral Contraceptives are not recommended to correct Menstrual Cycles
- Does not correct the underlying energy deficiency, and masks the endocrinopathy
XI. Resources
- Dietary Analysis Tool for Athletes
- Athlete Diet Index (University of Sidney)