Understanding Relative Energy Deficiency in Sport (RED-S)
Relative Energy Deficiency in Sport (RED-S) is a syndrome that occurs when an athlete's energy intake is insufficient to cover the energy expended during exercise and support the body's essential physiological functions. This prolonged state of 'low energy availability' (LEA) is often mistaken for simple fatigue, but its consequences are systemic and severe, impacting metabolic rate, hormonal balance, bone health, and immune function. While once thought to primarily affect female athletes (as the 'Female Athlete Triad'), the condition is now recognized in athletes of all genders, highlighting the need for widespread education and awareness. Both intentional under-fueling for performance or body image and unintentional under-fueling due to a lack of knowledge or resources can lead to RED-S. The key to prevention is closing this energy gap through smart and consistent fueling strategies.
Foundational Nutrition Strategies for RED-S Prevention
At the core of preventing RED-S is the concept of fueling for the work required. An athlete's nutritional needs are dynamic, shifting with training volume, intensity, and phases of the season. A consistent approach to fueling, with regular meals and snacks, is vital to ensure your body has the necessary energy and nutrients to perform and recover.
The Critical Role of Carbohydrates
Carbohydrates are the body's primary and most efficient energy source, especially for high-intensity exercise. A common misconception is that all calories are equal, but recent research shows that insufficient carbohydrate intake can trigger a state of low energy availability even if total caloric intake appears adequate. Without enough carbs, the body enters a state of physiological stress, impacting hormonal function and overall health. For athletes, especially those in endurance sports, carbohydrates should make up a significant portion of their diet—often over 50%.
Macronutrient and Micronutrient Balance
Beyond carbohydrates, a balanced diet incorporating adequate protein, healthy fats, and crucial micronutrients is essential. Protein is vital for muscle repair and synthesis. Fats are necessary for hormone production, vitamin absorption, and serving as a long-term energy source, particularly during lower-intensity exercise. Micronutrients like calcium, vitamin D, and iron are also critical, with deficiencies being common consequences of RED-S.
Here is a list of dietary priorities for preventing RED-S:
- Prioritize Carbohydrates: Ensure adequate intake, especially before, during, and after training sessions, to replenish glycogen stores.
- Eat Consistently: Aim for three balanced meals and strategically timed snacks to maintain a steady energy supply throughout the day and avoid large energy deficits.
- Incorporate Nutrient-Dense Foods: Focus on whole foods, including fruits, vegetables, whole grains, and healthy protein and fat sources, to maximize nutritional value.
- Stay Hydrated: Proper hydration is a key component of overall energy balance and health. Pay attention to fluid needs, especially during and after exercise.
- Consider Energy-Dense Snacks: During periods of high training load, include energy-dense but nutritious foods like nuts, dried fruits, and fortified dairy to meet increased caloric demands.
Comparison: Under-Fueled vs. Well-Fueled Athlete
To highlight the impact of proper nutrition, here is a comparison of two athletes:
| Aspect | Under-Fueled Athlete (Risk of RED-S) | Well-Fueled Athlete (Preventing RED-S) |
|---|---|---|
| Energy Levels | Chronic fatigue, low energy, and 'bonking' during training. | Consistent energy, strong performance, and efficient recovery. |
| Athletic Performance | Decreased endurance, strength, and coordination. Impaired judgment and concentration. | Increased endurance and strength. Improved training response and mental clarity. |
| Injury Risk | Higher risk of stress fractures and overuse injuries due to reduced bone mineral density. | Lower risk of injury with stronger bones and efficient tissue repair. |
| Hormonal Health | Disrupted menstrual cycles (females) and low testosterone (males). Reduced libido. | Normal hormonal function, supporting overall health and reproductive well-being. |
| Immune System | Increased frequency of illnesses, such as colds and infections, due to a compromised immune system. | Robust immune function, with fewer sick days and better health. |
| Mood & Psychological | Irritability, low mood, anxiety, and loss of enjoyment in sport. | Improved mood, better concentration, and enjoyment of training. |
Optimizing Fueling Around Your Training Schedule
Timing your nutrition strategically is just as important as the content of your diet. Athletes should focus on fueling before, during, and after exercise to maximize performance and recovery.
Pre-Exercise Fueling
Eating a carbohydrate-rich meal or snack 1-4 hours before exercise provides the necessary fuel for your muscles. For shorter, lighter sessions, a small snack like a banana and peanut butter might suffice. Before longer, more intense training, a larger meal with complex carbohydrates, a lean protein, and some healthy fats is better.
Fueling During Exercise
For exercise lasting longer than 60-90 minutes, consuming carbohydrates during the session is crucial to maintain energy levels and delay fatigue. Sports drinks, gels, or bars provide easily digestible carbohydrates to keep you going.
Post-Exercise Recovery
Post-exercise nutrition is vital for recovery and adaptation. The body is most receptive to nutrient uptake in the hour following a workout. A recovery meal or snack should include both carbohydrates to replenish glycogen stores and protein to repair muscle tissue. Chocolate milk, a protein shake, or a turkey sandwich are all great options.
Lifestyle and Professional Guidance
Beyond the plate, several lifestyle factors contribute to RED-S prevention. Adequate sleep, stress management, and avoiding excessive focus on weight are all key. Perhaps most importantly, seeking guidance from qualified professionals is recommended. A sports dietitian can help create a personalized nutrition plan, especially for athletes with high energy demands or specific body composition goals. Additionally, education for athletes, coaches, and parents is a powerful tool to foster healthy attitudes and behaviors. The International Olympic Committee offers resources and a Clinical Assessment Tool for medical providers to screen for RED-S. You can find more information from the expert body REDinSport at their website.
Conclusion Avoiding RED-S is not about perfection, but about sustainable, consistent, and balanced nutrition that respects your body's demands for both sport and health. By prioritizing carbohydrates, fueling regularly, and listening to your body's signals, you can maintain optimal energy availability. This proactive approach safeguards your well-being, supports peak performance, and ensures a long, healthy athletic career.
