Understanding RED-S: The Hidden Threat to Athletic Performance and Health

It is 5:00 a.m. when the alarm sounds in my dorm room. My heart is already pounding against my chest in anticipation; my body knows the routine all too well. Exhausted and depleted, I lace up my running shoes and head out the door. With a strict schedule to keep, I need to complete this workout and arrive at my internship by 9:00 a.m.

This run was simply another item to check off my training log, a standard mid-week, medium-long run. Descending toward the Schuylkill River, I remember thinking how beautiful and peaceful Philadelphia is at this hour. Yet, beneath that appreciation was a quiet, nagging realization: my body did not want to do this. Still, I never questioned the schedule. I was driven, disciplined, and a high achiever. As I pounded the pavement and sprinted toward the finish, my primary emotion was not accomplishment, but pure relief that I could finally move on with my day.

What I failed to realize at the time was that my body was screaming for rest, fuel, and recovery. I believed I was training to win, but in reality, I was training to fail.

As a full-time student-athlete, I was not consuming enough calories to sustain my rigorous training volume. Instead of building fitness, each consecutive workout became a setback to my recovery. Without adequate rest or fuel, my body could not integrate the hard work I was putting in. Despite my profound love for the sport and an intense desire to run faster, my mental health began to deteriorate. I became anxious and depressed, found myself constantly obsessing over food, and even caught myself wishing for an injury, simply so I would have a permissible excuse to rest.

I was experiencing Relative Energy Deficiency in Sport (RED-S).

What is RED-S?

RED-S is a clinical syndrome characterized by a mismatch between an athlete’s caloric intake and the energy expended during exercise and daily living. When the body receives insufficient calories to sustain both basic physiological functions such as respiration, heart rate, and organ operation and the demands of athletic training, it enters a state of Low Energy Availability (LEA). To survive, the body begins to suppress non-essential biological processes, severely compromising both long-term health and athletic performance.

Recognizing the warning signs of RED-S is critical for athletes, coaches, and practitioners alike.

Common physical symptoms

• Chronic fatigue: Feeling perpetually exhausted and experiencing prolonged recovery times after standard workouts.
• Frequent injuries: Suffering from recurrent stress fractures, persistent muscle strains, or abnormally slow healing times.
• Gastrointestinal distress: Experiencing frequent bloating, gas, constipation, or severe abdominal cramps.
• Impaired thermoregulation: Feeling chronically cold or struggling to maintain normal body temperature.
• Dermatological issues: Noticing sudden hair thinning, hair loss, or excessively dry skin.

Performance and psychological changes

• Declining fitness: Experiencing a noticeable drop in athletic stamina, strength, or speed despite consistent, hard training.
• Cognitive dysfunction: Struggling with mental fog, poor focus, lack of concentration, or memory lapses.
• Mood disturbances: Exhibiting increased levels of anxiety, irritability, or clinical depression.

Hormonal indicators

• Female athletes: Experiencing irregular, abnormally light, or completely absent menstrual periods (amenorrhea).
• Male athletes: Experiencing a suppressed libido, lowered testosterone levels, or erectile dysfunction.

Moving forward: awareness and recovery

Looking back, I realize I could have achieved far greater athletic heights had I properly fueled my training.

My mission now is to raise awareness about RED-S so that athletes are educated on the risks and understand that they are not alone in this struggle.

I entirely understand the deep desire to stay in the game and compete at your highest level. My ultimate goal is to provide the education and support necessary to help you navigate your relationship with fuel and training, allowing you to return to your sport in a safe, healthy, and sustainable way.

If you are an athlete, a coach, or a clinician wondering whether this is what you are seeing, read more about how I work with athletes and RED-S.