RED-S
RED-S (Relative Energy Deficiency in Sport) is a condition in which energy intake is insufficient over time relative to the body's needs for training, recovery, growth, and other physiological functions. It can affect hormonal function, bone health, immunity, metabolism, and athletic performance.
Early signs may include increased fatigue, poorer recovery, recurrent minor injuries, reduced training response, irritability, or declining performance. These symptoms are non-specific and do not by themselves establish RED-S.
RED-S develops when the body receives too little energy over time relative to total energy expenditure. This may occur unintentionally, for example with high training loads and insufficient recovery, or through intentional dietary restriction.
Common contributing factors
- •High training or competition load
- •Insufficient energy intake
- •Rapid or repeated weight loss
- •Restrictive eating or disordered eating behaviours
- •Insufficient recovery
- •Periods of growth in young athletes
- •Insufficient understanding of energy and nutritional needs
Prevention primarily involves ensuring adequate energy and nutrition in relation to training, competition, recovery, and growth. RED-S can occur in athletes who do not consider themselves underweight.
- •Plan nutrition and recovery alongside training load
- •Avoid unnecessary or rapid weight loss
- •Pay attention to persistent fatigue, performance decline, and injuries
- •Monitor menstrual patterns where relevant
- •Take recurrent stress fractures or other overuse injuries seriously
- •Seek help early when low energy availability is suspected
Reduce training load when appropriate and ensure adequate energy and nutrient intake. Athletes with persistent or combined symptoms should be assessed by a healthcare professional and, when appropriate, a sports dietitian.
Load and nutrition
Training load and energy intake are adjusted to support recovery and physiological needs.
Goals
Improved recovery and stable energy availability.
Progression criteria
Energy intake, recovery, and training load are balanced without clear adverse symptoms.
Gradual return
Training load is gradually increased as recovery and health improve.
Goals
Restore normal training capacity without recurrence of symptoms or injuries.
Progression criteria
Increased load is tolerated with adequate recovery and medical follow-up when required.
- Adequate energy and nutrient intake
- Normal or improving recovery
- No significant ongoing bone stress or other overuse injury
- Training load can be increased without clear deterioration
- Medical assessment when symptoms persist or are combined
The information in the Injury Center is for educational purposes and does not replace professional medical advice. Always consult a qualified healthcare professional for diagnosis and treatment.
RED-S
RED-S (Relative Energy Deficiency in Sport) is a condition in which energy intake is insufficient over time relative to the body's needs for training, recovery, growth, and other physiological functions. It can affect hormonal function, bone health, immunity, metabolism, and athletic performance.
Mild — Förbättring kan ske över veckor till månader, men återhämtningstiden varierar beroende på hur länge tillståndet funnits och vilka kroppsfunktioner som påverkats.
Symptoms
Early signs may include increased fatigue, poorer recovery, recurrent minor injuries, reduced training response, irritability, or declining performance. These symptoms are non-specific and do not by themselves establish RED-S.
Acute Treatment
Reduce training load when appropriate and ensure adequate energy and nutrient intake. Athletes with persistent or combined symptoms should be assessed by a healthcare professional and, when appropriate, a sports dietitian.
Rehabilitation
Training load and energy intake are adjusted to support recovery and physiological needs.
Goals
Improved recovery and stable energy availability.
Progression criteria
Energy intake, recovery, and training load are balanced without clear adverse symptoms.
Training load is gradually increased as recovery and health improve.
Goals
Restore normal training capacity without recurrence of symptoms or injuries.
Progression criteria
Increased load is tolerated with adequate recovery and medical follow-up when required.
Return to Play
- ☐ Adequate energy and nutrient intake
- ☐ Normal or improving recovery
- ☐ No significant ongoing bone stress or other overuse injury
- ☐ Training load can be increased without clear deterioration
- ☐ Medical assessment when symptoms persist or are combined
Moderate — Ofta månader snarare än dagar eller veckor. Olika delar av hälsan kan återhämta sig i olika takt.
Symptoms
More pronounced signs may include recurrent injuries, persistent fatigue, clear performance decline, menstrual dysfunction, frequent illness, or other signs of impaired physiological function.
Acute Treatment
The athlete should be assessed by a healthcare professional. Training load may need to be reduced, while nutrition, recovery, and any underlying problems should be addressed systematically.
Rehabilitation
Assessment of energy availability, training load, recovery, and relevant health symptoms.
Goals
Identify and address factors contributing to RED-S.
Progression criteria
An individualized treatment and load-management plan is established.
Energy intake and recovery are prioritized while training load is gradually adjusted.
Goals
Restore health, recovery, and physical capacity.
Progression criteria
Increased training is tolerated without deterioration in relevant health markers or symptoms.
Return to Play
- ☐ Adequate energy intake and recovery are established
- ☐ Current injuries are under control
- ☐ Training load can be managed without deterioration
- ☐ Relevant medical follow-up has been completed
- ☐ An individualized follow-up plan is in place
Severe — Kan kräva flera månader eller längre beroende på graden av fysiologisk påverkan och eventuella komplikationer.
Symptoms
Severe RED-S may involve significant physiological impairment, such as severe energy deficiency, significant menstrual or hormonal dysfunction, recurrent or high-risk bone stress injuries, fainting, or other medical complications.
Acute Treatment
Severe symptoms require medical assessment. Emergency care should be sought for fainting, seizures, severe weakness, or other acute medical complications.
Rehabilitation
Treatment is individualized and may require a multidisciplinary team including a physician, dietitian, and physiotherapist.
Goals
Stabilize health and treat medical consequences.
Progression criteria
Medical assessment confirms that gradual physical activity is safe.
Training load is rebuilt gradually as recovery progresses.
Goals
Return to sport without compromising health.
Progression criteria
The medical team determines that full training and competition are safe.
Return to Play
- ☐ Medical stabilization has been achieved
- ☐ Any bone stress injuries have been addressed
- ☐ Energy and recovery needs are being met
- ☐ Training load can be managed without deterioration in health
- ☐ Medical clearance before full competition load
When to Seek Medical Care
Suspected RED-S should be assessed by a healthcare professional, particularly when multiple signs occur together or health and training capacity are affected.
- Recurrent stress fractures or other overuse injuries
- Clear and persistent performance decline
- Persistent fatigue or impaired recovery
- Menstrual dysfunction or absence of menstruation
- Significant weight change or restrictive eating
- Fainting, dizziness, or severe weakness
- Signs of an eating disorder or severe disordered eating
References
- 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs) — International Olympic Committee / British Journal of Sports Medicine (https://doi.org/10.1136/bjsports-2023-106994)
- IOC REDs Clinical Assessment Tool Version 2 — International Olympic Committee / British Journal of Sports Medicine (https://doi.org/10.1136/bjsports-2023-106914)