Relative Energy Deficit in Sport (RED-S)

Article by Zoe Russell

Relative Energy Deficiency in Sport (RED-S)

What is RED-S?

Relative Energy Deficiency in Sport (RED-S) is a condition that is defined as ‘impaired physiological functioning caused by relative energy deficiency. In plain English, this means a state of being in your body which means there’s not enough energy supply for the demands you’re asking your body to perform, leading to weakening or injury in the system. The relative deficiency of energy has negative consequences for bone health, menstrual health, metabolic rate, immunity, protein synthesis, immunity, cardiovascular health and performance outcomes.

Historically, RED-S was called the ‘Female Athlete Triad’. Research in the last decade or so has increased our understanding of this phenomenon and its far-reaching consequences. Previously, the medical community was aware of the three main ‘symptoms’ of the Triad – high demands of physical activity, impaired menstrual function and decreased bone health. Health professionals believed that this condition was only occurring in females. As the research has uncovered more facets to RED-S, the name and definition had to be expanded to accurately reflect our new ways of measuring Low Energy Availability (LEA), the recognition of males with RED-S, identifying many other health parameters that are affected, and to highlight to the sporting community the negative ramifications for athlete performance. (Mountjoy, et al., 2018)

What Causes RED-S?

RED-S is caused by a prolonged state of Low Energy Availability (LEA). This is where the balance between energy (i.e. food) is tipped out of balance with energy out (i.e. activity). This can occur in many ways and is not always a sudden change, making identifying the causes difficult without help from trained medical professionals and coaches. Some examples might be an increase in sport or training load, decreased food intake or type of foods eaten, increased stress to the body through a lack of sleep, growth spurt, illness, or psychological stress.

What Are RED-S Symptoms?

Symptoms of RED-S are broad and cross over with many other conditions and illnesses. This can make it tricky to recognise and diagnose. (Mountjoy, et al., 2018)

Symptoms and other associated conditions your health professional might ask you about when they suspect RED-S might include:

  • Recent weight loss
  • Loss of appetite, disordered eating, or a history of eating disorders
  • Participation in high demand, weight or aesthetically driven sport (e.g. dance, gymnastics, jockeys, boxing etc.)
  • Slow or stunted growth in children and adolescents
  • Recurrent coughs, colds and cases of flu
  • Recent irritability, mood swings, or a history of mental illness or increased stress
  • Poor judgement, poor coordination, decreased athletic performance
  • Low iron or anaemia
  • Changes in or absence of a menstrual cycle in adults or a delayed or absent onset of puberty in adolescents
  • History of stress fractures
  • Recurrent or unhealed injuries
  • Feeling tired, run-down or exhausted
  • Difficulty sleeping or concentrating

How Is RED-S Diagnosed?

Diagnosis can be tricky for RED-S as symptoms vary, and everyone’s body responds differently to LEA. Energy availability is a sliding scale that constantly changes as we eat, move, rest and challenge ourselves. (Couanis, 2017)

Diagnosis can also be made tricky by an athlete’s coping skills and their motivations for revealing or minimising their symptoms to their coaches, trainers, family, friends, and themselves. Generally, the person feels and looks pretty run down because the body isn’t getting enough fuel to perform all the activity.

Often, athletes are recognised as being in an energy deficient state when it leads to them becoming injured or developing other conditions for seeking medical treatment. It is then up to the medical professional they seek help from to recognise the signs and symptoms and get the athlete the appropriate type of help they need to heal well and stay well. Most often, these treatments need to be multifactorial and involve a few different types of practitioners.

What Are Your RED-S Treatment Options?

Treatment options are based on the signs and symptoms each individual has, what their greatest concerns are, and the results of any tests or investigations. A mix usually delivers treatments of professionals, which might include:

  • Sports Dieticians, to address food-related behaviours
  • Physiotherapists, for injury management and rehabilitation advice
  • Exercise Physiologists, for reconditioning and modification of training/performance tasks
  • GPs and Team Doctors, to manage symptoms, prescribe medication and order tests, and clear for return to sport
  • Sports Psychologists and Psychiatrists, to help develop coping skills and address the thinking and beliefs around the current behaviours which led to RED-S
  • Endocrinologists, to help address hormonal imbalances
  • Gynaecologists and fertility specialists, to address hormonal and reproductive concerns
  • Cardiologists, where heart function has changed
  • Immunologist, to assist with the immune system and allergy concerns

Not everyone who has RED-S will require intervention from every single type of medical professional. Everyone is different, but most people who have RED-S have at least 3-4 professionals involved in their treatment team based on their needs.

This team of experts works very closely with the athlete, their family, teammates, coaches and trainers to ensure that the factors influencing energy availability are the most beneficial ones possible for the entire team or club. The best tool we have to reduce further injury and illness risk is education and advising everyone involved about training load, nutrition, coping strategies and sleep hygiene to get the most out of the athletes in a healthy, sustainable way.

Screening and prevention programs are becoming more popular throughout the sporting world. We know that early detection of RED-S is crucial for preventing long-term health consequences.

What Results Can You Expect?

Results for RED-S vary widely, dependent on which symptoms an athlete presents with and their severity and complexity. Each treatment plan is bespoke and will require the collaboration of many professionals.

If RED-S is a result of simply unintentional undereating or over-training, a little bit of knowledge and guidance can resolve RED-S quite quickly. However, if RED-S hasn’t been recognised and other health conditions have developed, treatment timeframes will vary depending on those conditions.

If you suspect that you or your child might be suffering from Relative Energy Deficiency in Sport (RED-S), you can book a consultation with your PhysioWorks physiotherapist.

Article by Zoe Russell

Sports Physiotherapy FAQs

sports physiotherapist brisbane

Sports Physiotherapy is the specialised branch of physiotherapy which deals with injuries and issues related to spokespeople. Practitioners with additional formal training within Australia are Sports & Exercise Physiotherapists.

What is Sports Physiotherapy?

Sports injuries do differ from common everyday injuries. Athletes usually require high-level performance and demands placed upon their bodies, which stresses their muscles, joints and bones to the limit. Sports physiotherapists help athletes recover from sporting injuries and provide education and resources to prevent problems. Each sports physiotherapist usually has sport-specific knowledge that addresses acute, chronic and overuse injuries. Their services are generally available to sportsmen and women of all ages engaged in sports at any level of competition.

Members of Sports Physiotherapy Australia (SPA) have experience and knowledge of the latest evidence-based practice, professional assessment and diagnosis of sports injuries, and effective hands-on management techniques and exercise protocols to assist recovery and prevent future damage. SPA members have access to the most recent advances in sports physiotherapy. You'll be pleased to know that most PhysioWorks physiotherapists and massage therapists are particularly interested in sports injury management.

General Sports Physio FAQs

Injury Management

Sports Massage

Sports Insurance

More Information

Understanding Common Muscle Injuries: A Comprehensive Guide

Muscle pain, also known as myalgia, can result from various causes and can affect different areas of the body. Managing and preventing discomfort requires a clear understanding of these common muscle injuries. This comprehensive guide aims to explore several sources of muscle pain, including injuries in the neck and back, strains in the lower limbs, conditions in the upper limbs, systemic causes, and more.

To provide valuable insights into the management of common muscle injuries, this guide offers answers to frequently asked questions and suggests products that can aid in your recovery. Access additional information about each specific injury by clicking the provided links.

Neck & Back Muscle Injuries

Lower Limb Muscle Injuries

Upper Limb Muscle Injuries

Haematoma-Related Myalgia

Fatigue-Related Myalgia

Systemic Causes of Myalgia

More Information: Myalgia

FAQs & Products

Common Ligament Injuries

Ligament injuries are common in the human body, often causing pain, discomfort, and limitations in mobility.

Various body parts are prone to ligament injuries, such as the knee, ankle, shoulder, wrist, hand, and spine. Among the most prevalent are knee ligament injuries, which include ACL (Anterior Cruciate Ligament) and PCL (Posterior Cruciate Ligament) injuries, as well as MCL (Medial Collateral Ligament) and LCL (Lateral Collateral Ligament) sprains.

In addition, ligament injuries can affect other areas, such as the shoulder, leading to AC (Acromioclavicular) joint injuries and dislocated shoulders. Wrist and hand ligament injuries, including thumb and finger sprains, are also common. Furthermore, ligament injuries can occur in the spine, resulting in back and neck sprains and conditions like "text neck" and whiplash. Understanding these common ligament injuries is essential for prevention, early diagnosis, and effective treatment, enabling individuals to regain their functionality and resume their daily activities.

Knee Ligament Injuries

Ankle Ligament Injuries

Shoulder Ligament Injuries

Wrist & Hand Ligament Injuries

Spinal Ligament Injuries


Couanis, G. (2017). Relative Energy Deficiency in Sport (RED-S). Retrieved from on the 28/05/2020.

Fede, C., Pirri, C., Fan, C., Albertin, G., Porzionato, A., Macchi, V. … Stecco, C. (2019). Sensitivity of the fasciae to sex hormone levels: Modulation of collagen-I, collagen-III and fibrillin production. PLoS ONE 14(9): e0223195. 10.1371/journal.pone.0223195

Mountjoy, M. Sundgot-Borgen, J. K., Burke, L. M., Carter, S., Constantini, N., Lebrun, C. … Ackerman, K. (2015). The IOC relative energy deficiency in sport clinical assessment tool (RED-S CAT). British Journal of Sports Medicine. 2015;49:1354

Mountjoy, M., Sundgot-Borgen, J. K., Burke, L. M., Ackerman, K. E., Blauwet, C., Constantini, N. … Budgett, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update British Journal of Sports Medicine 2018;52:687-697

British Journal of Sports Medicine. (2015) Relative Energy Deficiency in Sport (RED-S) Clinical Assessment Tool (CAT). British Journal of Sports Medicine. Retrieved from on 28/05/2020

You've just added this product to the cart: