RED-S (Relative Energy Deficiency in Sport)
RED-S, or Relative Energy Deficiency in Sport, is a condition that arises when the energy consumed through food is insufficient to meet the demands of exercise and vital bodily functions like growth, breathing, and digestion.
When we underestimate how much energy our activities require or deliberately reduce our intake, our bodies can enter a state of low energy availability. Similar to a phone on low battery mode, this causes the body to prioritise essential functions at the expense of others. Without proper “recharging,” this can compromise both long-term health and athletic performance.
It’s a situation that can happen to anybody, athlete or not, and at any time. Understanding the signs and symptoms is the first step to preventing or overcoming RED-S.
What causes RED-S?
RED-S occurs when there is a consistent mismatch between calories consumed and energy expended. Common factors include:
- Caloric restriction (intentional or unintentional) to alter body composition.
- Misjudging the energy needs of exercise, especially in endurance sports.
- Increased training intensity without corresponding increases in nutrition.
- Poor meal timing, with prolonged gaps causing energy deficits.
- Suppressed appetite or gastrointestinal issues before or after exercise.
- Disordered eating patterns or clinical eating disorders.
What are the symptoms?
Physical Symptoms
Logging sleep, mood, and energy levels alongside training data helps identify patterns and assess how your body is adapting.
Consulting a registered dietitian can ensure your energy intake matches your activity levels.
Chronic under-fueling can affect bone and soft tissue health, leading to recurring injuries. Consider a DEXA scan to assess bone density if injuries persist.
Low energy availability weakens the immune system, making frequent illnesses or prolonged recovery a concern.
Persistent fatigue, fluctuating energy levels, or stagnating progress in training could indicate imbalances in nutrition, recovery, and workload.
Changes like missed or irregular periods can be a red flag for low energy availability. Apps like FitrWoman and Flo can help track patterns.
Be aware that hormonal contraceptives might mask symptoms, making it harder to identify issues related to menstrual health.
Reduced sex drive may signal hormonal disruption due to low energy.
Athletes may need higher iron levels than the general population. Speak to a healthcare professional about optimal ranges.
Psychological Symptoms
Increased irritability, poor concentration, or feelings of depression can be signs of RED-S.
Noticeable changes in social life, libido, or overall enthusiasm for non-training activities are also key indicators.
Negative thoughts about body size or shape, believing weight changes will improve performance.
A distorted self-perception where your reflection doesn’t match reality or external feedback.
Avoiding specific food groups or feeling anxious at mealtimes may indicate disordered eating patterns.
Spending excessive time thinking about food, “earning” meals, or eating less on rest days are potential red flags.
Struggling to rest, avoiding rest days, or feeling compelled to add extra training can signal an unhealthy exercise mindset.
Sticking rigidly to plans despite physical signs like pain or exhaustion may indicate deeper issues.
Who is at risk?
Any active individual can develop RED-S, regardless of age, gender, or athletic level. Risk is heightened for:
- Endurance athletes with high training loads and a focus on leanness.
- Sports emphasizing aesthetics, such as dance or gymnastics.
Even recreational athletes juggling busy work or academic schedules face challenges in achieving adequate nutrition and rest.
Diagnosis and Support
Diagnosing RED-S requires a comprehensive approach, including blood tests, DEXA scans, and assessments of training and dietary habits. Unfortunately, awareness among general practitioners may be limited, so seeking a Sports Medicine Doctor or RED-S specialist can be crucial.
For those experiencing menstrual irregularities, hormonal contraceptives are not a solution, as they can mask underlying issues. Addressing the root cause is essential.
It’s also worth remembering that:
- Weight is not a sole indicator: RED-S can affect individuals of all body shapes and sizes, as responses to energy deficits vary.
- Not all cases involve disordered eating: While some athletes may experience disordered eating behaviors, RED-S can also occur from unintentional under-fueling due to busy schedules or increased training loads.
Getting Support
If you suspect RED-S, seek support from professionals familiar with the condition. Push for thorough evaluation if initial consultations feel dismissive. Early intervention is key to minimising long-term impacts on health and performance.
If you’re experiencing missed periods or recognise some of these symptoms, you can also consider booking an appointment in our Women’s Health Clinic with Dr Colinette Margerison.