You have certainly heard about RED-S, or at least experienced some of its signs firsthand, such as excessive fatigue, decreased performance, or difficulty recovering.
RED-S (Relative Energy Deficiency in Sport) occurs when an athlete does not consume enough energy to meet the demands of training, competition, and the body’s basic physiological functions. In other words, energy expenditure exceeds energy intake over a prolonged period.
This imbalance goes beyond performance and can affect hormones, bone health, immunity, recovery, and even mood. Often, the early signs are subtle, which makes prevention essential for those seeking consistent and sustainable progress in sport.
Understanding what RED-S is is the first step. The second—and most important—is knowing how to prevent it in practice. Small adjustments in nutrition, training planning, and the way you listen to your body can make a significant difference.
Below, we’ve gathered 6 simple, evidence-based tips to help you prevent RED-S and maintain health, performance, and consistency throughout the season.
1️⃣ Eat enough for your training load
It may seem obvious, but this is where many athletes go wrong. When training volume or intensity increases, nutrition must keep up. Maintaining an energy deficit for long periods—whether due to food restriction or poor planning—is the main trigger for RED-S.
If training goes up, energy intake needs to go up as well.
2️⃣ Don’t be afraid of carbohydrates
Carbohydrates are the primary fuel for intense and endurance training. Consuming too little carbohydrate, even when “eating well,” can lead to low energy availability.
Beyond supporting performance, carbohydrates aid recovery and reduce the physiological stress of training. Restrictive strategies should be occasional and well guided—not a daily rule.
3️⃣ Plan what you eat before, during, and after training
Going many hours without eating around training sessions increases the risk of RED-S. Ideally, nutrition should be viewed as part of training, not something separate.
Eating before training helps you train better.
Consuming carbohydrates during long or intense sessions protects performance.
Replenishing energy post-training accelerates recovery.
All of this contributes to overall energy balance throughout the week.
4️⃣ Don’t normalize extreme fatigue
Constant fatigue, performance decline, difficulty recovering, mood changes, and frequent injuries are not normal. They are often signs that the body is operating in an energy deficit.
Learning to listen to these signals is one of the most important ways to prevent RED-S.
5️⃣ Be cautious with weight and aesthetic obsession
Focusing too much on body weight, body fat percentage, or appearance can lead to unnecessary dietary restriction. In sport, performance comes from energy availability, recovery, and consistency—not just the number on the scale.
A well-fueled body responds better to training—simple as that.
6️⃣ Seek professional guidance
Every athlete has a different routine, training load, and energy requirement. Working with a sports dietitian and other health professionals helps fine-tune nutrition, identify early signs of RED-S, and build safer and more effective strategies.
