Identifying and Understanding RED-S

What is RED-S?

RED-S, or Relative Energy Deficiency in Sport, is a syndrome characterized by impaired physiological functioning caused by not having enough energy for your body to support your metabolic rate, menstrual function, bone health, immunity protein synthesis, and cardiovascular health. The evolution of our understanding of RED-S was adapted from the Female Athlete Triad. However, we know that RED-S is not limited to females. It can affect any athlete or active person.

RED-S is often a result of low energy availability, or LEA. LEA is “a mismatch between a person’s energy intake (via their diet) and the energy used in exercise. This results in an energy deficit, leaving inadequate energy to support the functions required by the body to maintain optimal health and performance” (Mountjoy, M., et al., 2018). In a nutshell, when you intentionally or unintentionally put yourself in a large energy deficit (whether through not eating enough food, exercising excessively, or a combination of both), you will have a low energy availability, putting you at a greater risk for developing RED-S.

RED-S is caused by undereating and may overlap with an eating disorder or patterns of disordered eating. Having an eating disorder or disordered eating may place you at a higher risk for developing RED-S. According to the British Journal of Sports Medicine, both male and female athletes have a 20% higher chance of developing an eating disorder, and furthermore, have a higher chance of having LEA (Dudgeon, E., 2019). Furthermore, according to a review published in the Journal of Eating Disorders, “45% of female recreational exercises were found to be at risk of LEA, while another study found a high LEA prevalence in both male and female elite young athletes (males, 56%; females, 51%)” (Sim, A., Burns, S.F. 2021). Research proves that both male and female elite or recreational athletes are at risk for LEA and subsequently at risk for RED-S.

It’s important to recognize that RED-S is not exclusive to athletes or those with an eating disorder. It can occur intentionally through dietary and exercise changes, or unintentionally, often as a result of a high level of training or exercise.

How common is RED-S?

If you are physically active, then you are potentially at risk for RED-S. Any type of consistent activity including going to the gym daily, regularly attending group fitness classes or running for leisure constitutes being physically active. However, competitive athletes may be at greater risk than others due to their drive to win or achieve a best time.

Endurance athletes or athletes that participate in sports that put a high emphasis on the idea that “leaner = faster” (which we will debunk in a future blog!) are also at particularly high risk. This includes sports such as distance running, gymnastics, swimming, and wrestling. Athletes who place high expectations or a great amount of pressure on themselves are at a greater risk of developing RED-S as well.

What are the symptoms of Relative Energy Deficiency in Sport?

There are many signs and symptoms that can indicate an athlete or active person as RED-S. However, these symptoms include particular sequelae that could indicate a wide array of conditions such as weight loss, reoccurring general illness (such as the common cold), anxiety or depression, concentration difficulties, gastrointestinal difficulties, decreased performance and muscle recovery, increased fatigue, and cardiac arrhythmias. So, it is important to consult with a Registered Dietitian or your primary care physician if you identify these symptoms.

While these symptoms can be indicative of a wide range of issues, when coupled with the following, more RED-S specific symptoms, there should be a higher suspicion of the pathology. Signs and symptoms that are highly prognostic of RED-S include obsession with eating/weight change, impairment of growth, development or endocrine systems, iron deficiency, decreased bone mineral density (which leads to increased risk for injury and stress fracture), and amenorrhea (skipped or irregular periods, which is NOT normal!)

How can you prevent the development of RED-S?

Increased awareness and education around RED-S can do wonders to help prevent it. As athletes and active people become accustomed to the definition and signs of RED-s, the higher the likelihood that cases will be identified and addressed in a timely manner, hopefully offsetting the prevalence of severe cases. Some simple tips for prevention of RED-s include listening to your body, fueling with appropriate amounts of food, and taking or implementing rest days as part of your schedule.

If you are unsure what that looks like for you, talking to a Registered Sports Dietitian to help you determine your individual needs can help you to become aware of potential RED-S symptoms, guide you in overcoming RED-S, and assist in your journey towards short and long-term goals you may have. As always, regular visits with your primary care provider, with open and honest dialogue about your exercise and dietary habits are key to maintaining optimal overall health.

Ultimately, remember that fueling properly is what gives you energy to enjoy the sport or activity you love most! Honor your hunger cues and allow yourself to eat when you are hungry, as well as replenishing your fuel pre- and post-workout/activity. We have plenty of resources for active people who are looking to optimize their performance plates, plan for busy days with prepped meals, or dial in their snacking for performance. You can find our Athlete’s Snack Guide here, which is an amazing resource for planning ahead for those snacks to fuel performance and promote recovery!

Being aware of RED-S as a constellation of signs and symptoms that is a result of intentional or unintentional dietary changes and low energy availability (LEA) that affects both male and female athletes/active people and has “…wide ranging adverse effects on all bodily systems and can seriously compromise long term health and performance” (Constantini, N., 2011) is important for all active people. As the saying goes, knowledge is power. Becoming knowledgeable about RED-S is one of the most powerful ways to identify and prevent it from derailing not only your training, but your overall health.

References: