Relative Energy Deficiency in Sport (RED-S) isn’t a term that rolls off the tongue, but for athletes and active individuals, it’s a crucial concept that needs attention. This condition, whose name changed from the “Female Athlete Triad,” in 2014, impacts both men and women and interferes with athletic performance and long-term health.
RED-S results from an imbalance between energy intake and energy expenditure, leading to symptoms such as chronic fatigue, frequent injuries, and impaired cognitive function. Below, we break down what RED-S is, how it manifests, and the steps needed to both prevent and reverse it. Understanding the science behind RED-S can help you optimise your training, protect your health, and ensure your body is functioning at its best.
What is RED-S?
Relative Energy Deficiency in Sport, or RED-S, is a condition stemming from insufficient energy intake relative to the demands of training and daily life. This creates an energy deficit, causing the body to ration its limited resources by dialling down key processes, like bone repair, immune response, and hormone production. While athletes and active individuals may think of calorie restriction as a quick way to lose weight, chronically low energy availability compromises everything from heart function to mental sharpness.
“Low energy availability not only affects performance but has serious health consequences for athletes, including menstrual disturbances, decreased bone health, and psychological issues.” Says Dr. Margo Mountjoy, from the British Journal of Sports Medicine’s 2014 International Olympic Committee Consensus Statement on RED-S.
The World Health Organization recognises RED-S as an increasingly critical issue, especially as athletic training intensity rises globally.
Causes of RED-S
The primary cause of RED-S is a mismatch between energy intake (calories consumed) and energy expenditure (calories burned). This creates what is known as low energy availability (LEA). This often happens when:
- Caloric Intake is too Low: Athletes reduce calorie intake in hopes of maintaining or lowering body weight, unaware of how much fuel their body truly requires.
- Training is Intensely Elevated: Frequent or high-intensity training burns calories rapidly, and without careful nutrition planning, it’s easy to fall into a deficit.
- Limited Recovery Time: Pushing the body to its limits without rest increases energy demands further.
- Dietary Restriction or Overemphasis on “Clean Eating”: Many athletes focus on low-calorie, nutrient-dense foods that may not provide enough overall calories to sustain their activity level.
However it’s important to note that the imbalance isn’t always intentional – for many athletes, it can just be a case of struggling to replace the energy lost through training. This may be caused by the sheer volume of food required to fulfil their calorie requirements. For example, if training for a marathon, consuming the correct number of calories through whole foods, which is preferred, can be challenging.
The average person burns 100 calories per mile while running. For example, if a training run is 17 miles, an individual will need to replace around 1700 calories on top of their daily expenditure. Physically consuming that much food, assuming it comes from whole sources, can be difficult to stomach.
The issue isn’t limited to elite athletes, also. A study by Sim and Burns indicated that 45% of female recreational exercisers were at risk of Low Energy Availability (LEA), which can lead to RED-S.
Recognising the Symptoms of RED-S
Symptoms of RED-S are widespread and impact multiple systems in the body. They range from subtle to severe, affecting athletes’ performance and health:
- Metabolic and Endocrine Dysfunction:
- Disrupted menstrual cycles (in females) or low testosterone levels (in males)
- Reduced thyroid hormone levels, which can slow metabolism
- Impaired bone health, leading to increased risk of fractures or osteoporosis
- Physical Symptoms:
- Chronic fatigue, lack of stamina, or inability to perform at normal intensity
- Frequent injuries, especially stress fractures and sprains
- Weakness, dizziness, or lightheadedness during or after exercise
- Mental and Cognitive Impairments:
- Difficulty concentrating, mental fog, or slower cognitive responses
- Increased irritability or mood swings
- Reduced Immunity:
- Susceptibility to illnesses, such as colds or infections
- Slower recovery times from illnesses or minor injuries
RED-S can masquerade as many different issues, so identifying the cause as energy imbalance is crucial. Even if you’re not experiencing all symptoms, any combination can indicate potential low energy availability.
How to Reverse RED-S
The good news? With proper adjustments, RED-S is often reversible. Recovery requires both dietary adjustments and changes to training load, so the body can rebalance energy levels and gradually restore vital functions.
1. Increase Caloric Intake
- Aim to eat balanced, nutrient-dense meals with a mix of proteins, fats, and carbohydrates to support recovery.
- Consider tracking calorie intake for a short period to understand daily needs better and ensure you’re meeting them.
- Don’t skip meals, and incorporate snacks if you’re frequently training or feeling hungry throughout the day.
2. Periodise Training Intensity and Frequency
- Schedule lower-intensity days and rest days to avoid continuous high-energy output.
- Match energy intake more closely with training load. For example, plan higher-calorie meals around intense training sessions.
3. Address Nutritional Deficiencies
- Certain nutrients – calcium, iron, vitamin D, and B vitamins – are especially vital for energy production and bone health. Consider blood tests to check for deficiencies and adjust your diet or supplements accordingly.
4. Seek Guidance from a Specialist
- If symptoms are advanced, working with a registered dietitian or sports nutritionist is essential. They can create a tailored nutrition plan and help manage calorie intake to support your unique activity level.
Key Takeaways
- RED-S is a serious condition caused by an imbalance between energy intake and energy expenditure, leading to symptoms that affect nearly every bodily function.
- Regularly monitor both caloric intake and training intensity to prevent RED-S from impacting your performance and health.
- Reversing RED-S involves increasing caloric intake, adjusting training loads, and possibly working with a specialist to rebuild energy balance safely.
Rebalancing your energy intake is the first step towards a healthier, stronger body. For many athletes, meal planning and nutritional support can make all the difference. Fresh Fitness Food offers tailored meals that make it easy to fuel up with the right calories and nutrients – because nothing should come between you and your performance.
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