Relative Energy Deficiency in Sport (RED-S)

What is Relative Energy Deficiency in Sport (RED-S)?

Relative Energy Deficiency in Sport (RED-S) is a condition caused by insufficient caloric intake relative to energy expenditure. It occurs when the body does not receive enough fuel to meet its energy demands. Often affecting athletes who overtrain without adequate nutrition. This imbalance disrupts physiological functions and can lead to various health complications in both men and women.

How do I know if I have Relative Energy Deficiency in Sport?

If you exercise at a high intensity or are involved in high-level sport. And have a combination of some the following symptoms, it is best to consult with your primary care health practitioner who will be able to assess you further.

• Frequently feeling fatigued despite getting adequate sleep.
• Feeling irritable and experiencing mood changes.
• Iron deficiency can be a sign of RED-S.
• Females will notice symptoms involving changes in their menstrual cycle – periods may stop or become irregular.
• Reproductive health in males and females can be affected.
• In children and teenagers, growth can be affected.
• People with Relative Energy Deficiency in Sport may become ill with colds or flus more often than usual.
• Even though you may be increasing your conditioning, your ability to perform well in your sport may decrease.
• RED-S can cause stress fractures in athletes. And often it is only at this point that people seek medical attention and receive an official diagnosis of Relative Energy Deficiency in Sport.
• Severe or chronic RED-S can affect the heart.
• In the long run Relative Energy Deficiency in Sport can make you prone to early onset osteoporosis.

It is important to note that in males, diagnosing Relative Energy Deficiency in Sport can be more challenging. As physiological changes are less obvious. Whereas in females with RED-S, irregular or absent periods are a common indicator of energy deficiency, men lack a clear early warning sign. For males, changes associated with decreased testosterone levels due to Relative Energy Deficiency in Sport are more subtle. And can be mistaken for over training or other health issues. If RED-S is suspected hormonal testing can be done. Your healthcare practitioner may also use a tool called a RED-S CAT to assist with diagnosis.

Effects of Relative Energy Deficiency in Sport on performance

• If the body is not receiving adequate energy intake, muscles will fatigue more quickly.
• Muscle hypertrophy and cardiovascular adaptation will not occur as usual in response to training if there is energy deficiency and lack of optimal nutrition.
• Hormonal changes resulting from RED-S will also affect muscle growth, as levels of testosterone decrease in males and females.
• Athletes will have a higher risk of injury and slower recovery from injury and illness. Due to lack of nutrition and adequate energy to allow the body to heal properly.
• Because of these effects, athletes will not be able to reach their maximum potential and will likely have to take more time away from their sport to allow for recovery. Overall performance will therefore be affected.

What can be done to prevent and treat RED-S?

It is important to seek medical attention if you are concerned about developing RED-S. Or if you notice any symptoms of Relative Energy Deficiency in Sport.

Prevention is key for relative energy deficiency in sport. This is because the long-term consequences of RED-S including effects to bone health, can take years to recover from once beginning treatment. This can have a serious impact on the career of an athlete and their ability to perform at their maximum potential. Bone injuries can lead to a lot of time away from training and competing.

If you are a high-performance athlete or sportsperson, you will likely have a team of coaches and health professionals involved in your training. Your medical team may utilise a tool called RED-S CAT to help to determine whether you are at low, medium, or high risk of developing Relative Energy Deficiency in Sport.

The most effective recovery from Relative Energy Deficiency in Sport involves a holistic approach with a multidisciplinary team, which may include a doctor, dietitian, physiotherapist, psychologist, and coach. The primary focus of treatment should be to address the gap between energy intake and energy expenditure. Injuries associated with RED-S will also need to be assessed and treated promptly.

This approach enables athletes to maximize their performance in sports while ensuring their short- and long-term health remains a top priority.

CITATIONS

1. Cabre HE, Moore SR, Smith-Ryan AE, Hackney AC. Relative Energy Deficiency in Sport (RED-S): Scientific, Clinical, and Practical Implications for the Female Athlete. Dtsch Z Sportmed. 2022;73(7):225-234. doi: 10.5960/dzsm.2022.546. Epub 2022 Nov 1. PMID: 36479178; PMCID: PMC9724109.
2. Br J Sports Med: first published as 10.1136/bjsports-2014-094559 on 17 March 2015. Downloaded from http: //bjsm .bmj. com/ on February 11, 2025 by guest