Relative Energy Deficiency in Sport
Relative Energy Deficiency in Sport: What Athletes Need to Know
Relative Energy Deficiency in Sport, commonly known as RED-S, develops when the body does not receive enough energy to support both exercise and normal everyday functions.
It can affect athletes of any age and at any level, including both men and women. Left unaddressed, RED-S can influence sporting performance, recovery, hormonal health, bone strength and general wellbeing.
The signs are not always obvious, which is why early recognition and appropriate support are so important.
Why does RED-S happen?
The body needs energy not only for training, but also for essential processes such as growth, hormone production, immune function, digestion and maintaining healthy bones.
RED-S occurs when too much of the available energy is being used for exercise, leaving insufficient energy for these other functions. This is sometimes referred to as low energy availability.
The imbalance may develop intentionally through restrictive eating or attempts to lose weight. However, it can also happen unintentionally when training volume increases without a corresponding increase in food intake.
Over time, this can affect metabolism, immunity, reproductive hormones, bone health and the body’s ability to recover from exercise.
Who is most at risk?
RED-S can occur in any sport, but the risk may be higher in activities where low body weight, leanness, endurance or appearance are seen as important.
This may include:
- long-distance running
- cycling
- swimming
- gymnastics
- dance
- combat and weight-category sports
- endurance and multi-sport events
Young athletes may be particularly vulnerable because their bodies also require energy for growth and development.
RED-S is sometimes more readily recognised in female athletes because of changes to the menstrual cycle. However, male athletes can also be affected, with symptoms such as reduced testosterone, lower libido, fatigue and impaired performance.
Possible signs of RED-S
The symptoms of RED-S can vary considerably and may develop gradually.
Changes to sporting performance are often among the first things an athlete notices. Training may begin to feel harder, recovery can take longer and previous performance levels may become difficult to maintain.
Other possible signs include:
- ongoing tiredness or unexplained fatigue
- a noticeable drop in performance
- frequent illness or infections
- repeated injuries or stress fractures
- slow recovery after training
- difficulty concentrating
- irritability, anxiety or changes in mood
- unintended weight loss
- persistently low body fat
- missed or irregular periods
- reduced testosterone or libido
No single symptom confirms RED-S. However, a combination of symptoms, particularly alongside a demanding training schedule, should be taken seriously.
What should you do if you are concerned?
It can be useful to look honestly at the relationship between training, recovery and nutrition.
Consider whether training demands have recently increased, meals are regularly being missed, certain food groups have been restricted or there is pressure to maintain a particular weight or body shape.
Keeping a simple record may help identify patterns. This could include:
- training duration and intensity
- meals and snacks
- energy levels
- sleep quality
- illnesses and injuries
- menstrual changes
- changes in mood or concentration
It may also be necessary to temporarily reduce training intensity or volume while energy intake and recovery are assessed.
However, RED-S should not usually be managed alone. Advice from a healthcare professional with experience in sports medicine or athlete nutrition is recommended.
When should you seek medical advice?
Arrange a medical assessment if you experience persistent fatigue, declining performance, repeated injuries or unexplained weight loss.
Women should seek advice if periods become irregular or stop altogether. Men should speak to a healthcare professional if they notice symptoms such as reduced libido, hormonal changes or an unexplained loss of strength and energy.
Repeated bone stress injuries or stress fractures also require proper investigation, particularly in younger athletes.
Depending on the symptoms, a clinician may recommend blood tests, hormone assessments, nutritional screening or a bone density scan.
How is RED-S managed?
The main aim of treatment is to restore sufficient energy availability.
This usually involves increasing energy intake, adjusting the training programme or using a combination of both. Any specific nutritional deficiencies should also be identified and addressed.
Recovery may require support from several professionals, such as:
- a sports medicine doctor
- a registered dietitian or sports nutritionist
- a physiotherapist
- a psychologist or mental health professional
- a coach working alongside the clinical team
Training may need to be reduced or modified for a period of time. In more significant cases, an athlete may be advised to pause competition while hormonal health, bone strength and general wellbeing recover.
The appropriate approach will depend on the athlete’s symptoms, medical findings, sport and training demands.
Protecting performance and long-term health
RED-S is not simply a problem of eating too little or training too much. It is a wider health condition that can affect several systems throughout the body.
When recognised early, the energy imbalance can often be corrected before more serious problems develop. With appropriate nutrition, medical support and sensible adjustments to training, many athletes can return to healthy participation and strong performance.
Ignoring the symptoms may increase the risk of ongoing fatigue, reduced immunity, poor bone health, fertility problems and recurring injury.
For athletes, parents and coaches, the key message is simple: adequate fuelling is an essential part of training, recovery and long-term sporting health.
If you’re struggling with some of the feelings described above, arrange a time to see Dr Jones; it’s simple to do via the contact form.
