RED-S: The Hidden Injury Risk Affecting Female Athletes
17 July 2026
You’re training consistently, eating what you think is a healthy diet, and doing everything you can to improve your performance.
Yet despite your efforts, you feel constantly fatigued, struggle to recover between sessions, pick up recurring injuries, or feel that your performance has plateaued.
For many athletes, these symptoms may be linked to a condition known as Relative Energy Deficiency in Sport (RED-S).
At TA Physiotherapy in Henley-on-Thames, we work with active women and female athletes to identify factors that may be affecting performance, recovery, and long-term health. RED-S is increasingly recognised as one of the most important—and often overlooked—issues in sport.
What Is RED-S?
Relative Energy Deficiency in Sport (RED-S) occurs when an athlete does not consume enough energy to meet the demands of both training and normal physiological function.
In simple terms, the body does not have enough available energy to support:
- Exercise performance
- Recovery
- Bone health
- Hormonal function
- Immune function
- Metabolism
- General health
RED-S can affect athletes of all ages and abilities, from recreational runners to elite competitors.
While it can affect both men and women, female athletes are particularly vulnerable due to the interaction between energy availability, hormones, and bone health.
Why Is RED-S Becoming More Common?
The popularity of endurance sports, running, cycling, Hyrox, CrossFit, and fitness challenges has increased dramatically over recent years.
Many athletes are encouraged to:
- Train more
- Eat less
- Lose weight
- Improve body composition
While these goals may appear beneficial, they can sometimes create an imbalance between energy intake and energy expenditure.
Over time, this imbalance can have significant consequences.
Research suggests that low energy availability is common in endurance athletes and is associated with increased injury risk and impaired performance.
Common Signs and Symptoms of RED-S
RED-S can present differently in every athlete.
Common warning signs include:
Persistent Fatigue
Athletes often report feeling unusually tired despite sleeping well and following their normal training routine.
Recurrent Injuries
Frequent injuries can be one of the first signs that the body is struggling to recover.
Common injuries include:
- Stress fractures
- Bone stress injuries
- Tendinopathy
- Muscle strains
Reduced Performance
Athletes may notice:
- Slower race times
- Reduced strength
- Poor recovery
- Difficulty maintaining training intensity
Menstrual Changes
Changes in menstrual function can occur when energy availability is insufficient.
This may include:
- Irregular periods
- Missed periods
- Changes in cycle length
These symptoms should never be ignored.
Increased Illness
Athletes with RED-S may experience more frequent colds and infections due to impaired immune function.
RED-S and Bone Health
One of the most significant concerns associated with RED-S is its impact on bone health.
Low energy availability can reduce bone formation and increase the risk of:
- Stress reactions
- Stress fractures
- Reduced bone mineral density
For runners and endurance athletes, this can result in months away from sport.
Research has shown that athletes with low energy availability have a significantly increased risk of bone stress injuries.
The earlier these issues are identified, the better the outcome.
Why Female Athletes Should Pay Particular Attention
Female athletes often face unique challenges.
Many are balancing:
- Sport
- Work
- Family commitments
- Academic pressures
At the same time, social media can create unrealistic expectations around body composition and appearance.
Unfortunately, many female athletes assume fatigue and under-fuelling are normal parts of training.
They are not.
Optimal performance requires adequate nutrition, recovery, and energy availability.
How Physiotherapy Can Help
Physiotherapists are often one of the first healthcare professionals athletes consult when injuries occur.
At TA Physiotherapy, we take a whole-athlete approach.
When recurring injuries, stress fractures, persistent fatigue, or unexplained performance issues are present, we consider whether RED-S could be contributing.
Our assessments may include:
Training Load Review
Understanding how much training you are completing and whether recovery is adequate.
Injury History Analysis
Identifying patterns that may indicate underlying issues.
Strength and Movement Assessment
Evaluating physical capacity and identifying areas for improvement.
Collaborative Care
Where appropriate, we may recommend working alongside:
- Sports dietitians
- Sports medicine doctors
- GPs
- Strength and conditioning coaches
Preventing RED-S
The good news is that RED-S is preventable.
Key strategies include:
Fuel for Performance
Nutrition should support training demands rather than restrict them.
Prioritise Recovery
Recovery is where adaptation occurs.
Without recovery, performance improvements become difficult.
Monitor Warning Signs
Don’t ignore:
- Persistent fatigue
- Recurrent injuries
- Menstrual changes
- Declining performance
Seek Advice Early
Early intervention often prevents more serious problems developing.
Female Athlete Support at TA Physiotherapy Henley
Emma Spong and Tom Astley provide evidence-based support for female athletes throughout Henley-on-Thames and the surrounding areas.
Whether you’re a runner, footballer, tennis player, golfer, cyclist, or gym enthusiast, our goal is to help you stay healthy, resilient, and performing at your best.
We understand that successful rehabilitation isn’t simply about treating injuries—it’s about understanding why they happened in the first place.
Looking Beyond the Injury
Many athletes focus solely on treating symptoms.
The most successful athletes understand the importance of addressing the underlying factors that influence performance and recovery.
If you’re struggling with recurring injuries, unexplained fatigue, or persistent performance issues, RED-S may be worth exploring.
Book a Female Athlete Assessment at TA Physiotherapy in Henley-on-Thames and let us help you build a stronger foundation for long-term sporting success.
References
- Mountjoy M, Sundgot-Borgen J, Burke L, et al. IOC Consensus Statement on Relative Energy Deficiency in Sport (RED-S): 2018 Update. British Journal of Sports Medicine. 2018.
- Ackerman KE, Misra M. Bone Health and the Female Athlete. Sports Health. 2011.
- De Souza MJ, Nattiv A, Joy E, et al. Female Athlete Triad Coalition Consensus Statement. British Journal of Sports Medicine. 2014.
- Logue D, Madigan SM, Delahunt E, et al. Low Energy Availability in Athletes: A Review of Prevalence, Dietary Patterns and Health Consequences. Sports Medicine. 2018.