In the world of youth sports, we often celebrate the “grind.” We praise the athlete who is the first one at practice and the last one to leave. But there is a silent, physiological breaking point where more effort stops leading to better results and starts leading to systemic breakdown.
This condition is known as RED-s (Relative Energy Deficiency in Sport).
What is RED-s? The Science of the “Energy Gap”
At its core, RED-s is a state of Low Energy Availability (LEA). It occurs when an athlete’s energy intake (food) is insufficient to support both their exercise energy expenditure and the basic functions required by the body for daily life and growth.
When the body realizes it is in an energy deficit, it begins to “power down” certain systems to ensure survival. It’s like a smartphone entering “Low Power Mode”—the screen dims, background apps close, and the processor slows down. In an athlete, those “background apps” are things like bone health, hormone production, and immune function.
Case Study 1: The Accidental Under-Fueler
The Athlete: “Maya,” a 15-year-old high school soccer player. The Situation: Maya had a massive growth spurt over the summer (3 inches). She kept her diet the same, but her training intensity increased as she made the Varsity team. The Symptoms: Maya started feeling “heavy-legged” by the second half of games. She stopped getting her period and developed a persistent pain in her shin that wouldn’t go away. The Diagnosis: Maya wasn’t “dieting.” She was simply an accidental under-fueler. Her body was using every calorie for soccer and growth, leaving nothing for her endocrine (hormonal) system. Her “shin pain” was an early-stage stress reaction because her bones weren’t getting the nutrients needed to repair themselves after impact.
Case Study 2: The Pressure of the “Ideal” Physique
The Athlete: “Leo,” a 17-year-old wrestler. The Situation: Leo felt he needed to “lean out” to stay in a lower weight class. He began cutting carbs and skipping post-workout meals. The Symptoms: Leo’s strength plateaued. He became uncharacteristically irritable and started struggling with focus in his AP classes. Despite training harder, his “explosiveness” on the mat vanished. The Diagnosis: Leo was suffering from intentional RED-s. By restricting his intake, his testosterone levels dropped (a common but rarely discussed symptom in male athletes), leading to muscle wasting and cognitive fatigue.
The Red Flag Checklist
How do you know if a young athlete is hitting the wall? Look for these “check engine” lights:
- The Plateau: Performance isn’t improving despite consistent training.
- The “Walking Wounded”: Lingering injuries or frequent “niggling” pains.
- The Social Shift: Withdrawal from friends or an obsession with “clean eating” that prevents them from eating with the team.
- The Missing Cycle: For female athletes, the loss of a period is never a normal side effect of “training hard”—it is a clinical red flag.
- Temperature Sensitivity: Feeling cold all the time, even in a warm gym.
The Consequences: It’s Not Just About Today
The danger of RED-s in youth athletes isn’t just about missing next week’s game. Adolescence is the peak window for bone mineral density (BMD) accretion. > Important Note: If an athlete does not build bone density during their teenage years due to RED-s, they may never be able to “make up” that loss later in life, significantly increasing their risk for osteoporosis and fractures in their 30s and 40s.
The Path Forward: Fueling for Greatness
Recovery from RED-s isn’t just about “eating more”; it’s about restoring the body’s trust that energy will be consistently available.
- Prioritize the “Recovery Window“: Ensure a snack with both protein and carbohydrates is consumed within 30–60 minutes after training.
- Education over Weight: Move the conversation away from “body composition” and toward “performance fueling.”
- Consult the Professionals: RED-s is a complex physiological issue. A sports dietitian and a physician who understands the RED-s Clinical Assessment Tool (CAT) are essential.
RED-s doesn’t have to be the end of a sports career, but it must be the start of a new approach to health. When we fuel our young athletes properly, we aren’t just building better players—we are building healthy adults. If you suspect your teenage athlete may be suffering from RED-s book a consultation with Corner on Wellness Chiropractic Center and their Nutrition consultant for an assessment.