“Running on Empty: The Hidden Costs of RED-S on Your Performance and Health”
What is RED-S?
Relative Energy Deficiency in Sport (RED-S) occurs when your body doesn’t get enough energy (calories) to meet the demands of your workouts and daily life. While often associated with elite athletes, RED-S can affect anyone—from weekend warriors to those working out to “look better naked.” It’s not just about not eating enough; it’s about creating a chronic energy deficit where your body has to choose between supporting exercise, recovery, and basic biological functions. Spoiler alert: survival wins.
RED-S disrupts everything from hormonal health and immune function to bone density and mental clarity. Symptoms include fatigue, frequent injuries, irritability, poor performance, and, for women, menstrual irregularities. While it might seem counterintuitive, under-fueling can also hinder body composition goals, as your body starts holding onto fat and breaking down muscle to survive.
How RED-S Affects Your Workouts and Performance
When your energy balance is off, so is your workout. Even if you’re showing up to the gym or clocking miles on the road, under-fueling sabotages your efforts. Without proper energy intake:
• Your muscles don’t recover properly, making you prone to injury.
• Your endurance tanks because glycogen stores (your body’s fuel) are depleted.
• Strength gains plateau because your body can’t repair and rebuild muscle effectively.
• You feel sluggish, unmotivated, or even dizzy during workouts.
Whether your goal is to crush a triathlon or simply feel more confident in your skin, ignoring the nutritional side of performance will eventually catch up with you.
Fuel Smarter: Advice from Experts
Dr. Stacey Sims and Dr. Andy Galpin, both leaders in the fields of performance and nutrition, emphasize the importance of fueling before and after workouts to avoid RED-S. Here are a few of their key recommendations:
Dr. Sims recommends:
Workouts Under 60 Minutes (Low-Moderate Intensity)
- Carbohydrates: 15-30 grams
- Protein: 15-20 grams
- Fats: Minimal
Workouts 60-90 Minutes (Moderate-High Intensity)
- Carbohydrates: 30 grams
- Protein: 20 grams
- Fats: Minimal
Workouts Over 90 Minutes (Endurance/High Intensity)
- Carbohydrates: 30 grams pre-workout. 30-60 grams per hour during exercise
- Protein: 20-25 grams pre-workout
- Fats: Minimal
Key Notes
1. The emphasis on easily digestible carbohydrates and avoiding heavy or fatty meals before training.
2. Protein intake for muscle protein synthesis should be prioritized.
3. Keep fats low pre-workout
It's important to note that Dr. Sims often emphasizes that women should not exercise on an empty stomach, particularly in the morning. She recommends about 100 calories of protein and 100 calories of carbs before any training.
Dr. Andy Galpin recommends:
Short-Duration Workouts (<60 Minutes)
- Carbohydrates: 15-30 grams
- Protein: 15-20 grams
Moderate-Duration Workouts (60-90 Minutes)
- Carbohydrates: 0.5 grams per pound of body weight
- Protein: 0.25 grams per pound of body weight
Long-Duration Workouts (>90 Minutes)
Dr. Galpin's notes that carbohydrate intake may need to be higher for very intense or prolonged endurance activities:
- Carbohydrates: 0.5-1 gram per pound of body weight
- Protein: 0.25 grams per pound of body weight
Fats:
Keep pre-workout fat intake minimal, fats can slow digestion and may not provide immediate energy for workouts.
Dr. Galpin stresses that total daily protein intake is more critical for muscle growth than precise timing relative to workouts.
Worth Noting:
Individual variability:
It's important to note that these recommendations are general guidelines and may need to be adjusted based on individual factors such as body composition, training intensity, and specific goals.
Hydration and Electrolytes:
Very Important to have this dialed in pre- during and post training. More on this in a separate post.
Previous Day Nutrition and Exercise:
The Day Before Matters
Your nutrition and exercise the day prior play a critical role in pre-workout fueling. Prioritizing balanced meals with sufficient carbs, protein, and hydration the night before ensures your body is prepared to perform at its best.
The Value of a Holistic Coach
RED-S highlights the interconnectedness of nutrition, training, and recovery. Working with a coach who understands all three components—not just one—is essential for both long-term performance and health. A coach who focuses solely on training might push you harder without considering your nutritional needs, while a nutrition-only expert might overlook the physical demands of your workouts.
7 BIO takes a comprehensive approach that considers the entire person—not just the training plan or macros. The 7 BIO philosophy prioritizes understanding your unique physiology, goals, and lifestyle to ensure you’re training and recovering in a way that unlocks your full potential.
Takeaway
RED-S is more than a buzzword; it’s a real issue that can derail your progress and harm your health. The good news? It’s preventable. By paying attention to pre-workout and pre-bed nutrition, fueling for the demands of your training, and partnering with a coach who sees the bigger picture, you can stay energized, healthy, and ready to crush your goals.