2. Recognizing RED-S: Early warning signs of energy deficiency in endurance sports
The "Relative Energy Deficiency in Sport" (RED-S) syndrome often creeps up unnoticed – yet early detection is crucial to prevent serious consequences for health and performance. Many athletes don't immediately attribute symptoms like fatigue, susceptibility to infections, or menstrual irregularities to energy deficiency. Therefore, it's all the more important to be aware of these warning signs.
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#### Typical physical symptoms
Energy deficiency becomes noticeable in the body quickly, but often only after weeks or months of insufficient calorie intake. Typical red flags include:
- Constant fatigue or unexpected drop in performance during training
- Frequent infections, prolonged recovery times, muscle soreness, poor sleep quality
- Weight loss, especially when accompanied by loss of strength or muscle mass
- Absence or irregular menstruation in women (amenorrhea, oligomenorrhea)
- Loss of libido, lack of morning erection in men
- Stress fractures, impaired bone density, increased injuries
- Increased irritability, difficulty concentrating or mood swings
These symptoms can also occur with other causes – however, a prolonged or recurring occurrence, especially in connection with increased training volume and calorie deficit, is indicative of RED-S [1][2].
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#### Mental and emotional warning signs
Energy deficiency doesn't just make the body feel weak: Many sufferers report inner restlessness, nervousness, or even depressive moods. Concentration problems, increased reluctance to exercise, and mood swings are further warning signs. Hormonal imbalances also disrupt sleep patterns, which can further impair recovery [1].
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#### Poor recovery and risk of injury
When the body lacks energy, regeneration is the first process affected. This manifests as persistent muscle soreness, slower healing of minor injuries, and an increased risk of overuse injuries. Stress fractures and premature bone loss are particularly dangerous. The immune system also reacts sensitively, becoming more susceptible to infections, as athletes often experience through recurring colds [1][2].
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#### Special characteristics of women and men
While absent or irregular periods in women have long been considered a warning sign of energy deficiency, typical male symptoms such as loss of libido, lack of morning erections, and increased fatigue are often overlooked. Both sexes also develop hormonal changes such as low estrogen or testosterone levels [2].
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#### Self-check: Am I at risk?
A simple but important step is to regularly and honestly observe your own energy intake and how your body feels:
- How often do I feel refreshed?
Will my weight remain stable despite training?
How often am I sick?
Are there any hormonal abnormalities or changes in sleep patterns?
- Is my training progress steadily declining?
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**Conclusion:**
Early detection of RED-S and taking the warning signs seriously – both physical and mental – are crucial. Anyone who notices these signs should review their calorie intake and training load and seek professional help if necessary. This is the only way to ensure the body remains healthy and performs well in the long term [1][2].
Sources
[1] RED-S Syndrome: A Guide to Relative Energy Deficit ... https://blackroll.com/de/artikel/red-s-syndrom
[2] Risk of RED-S in endurance athletes https://junkmiles.de/red-s-energie-defizit-ausdauersport/