What is RED-S?

Contributed by Abi Woodliffe-Thomas

Physical activity is so good for us, for both our physical and mental health. However, when there are internal or external pressures what was meant to be enjoyable and healthy for us can develop into unhealthy exercise and eating behaviours. This can have a negative impact on mental and physical health, including reduced sporting performance and injury.

What is RED-S?

Relative energy deficiency in sport (RED-S) is a condition characterised by insufficient energy intake and/or excessive energy expenditure (over-exercise). Consequences of this low-energy condition can alter many physiological systems, including metabolism, menstrual function, bone health, immunity, protein synthesis, and cardiovascular and psychological health (1). At a simplified level, it is an eating disorder in sport.

Who is at risk of developing RED-S?

There are common risk factors for RED-S including:

  • Personality traits such as competitiveness and perfectionism

  • Athletes performing in sports with high aesthetic value (e.g., ballet, gymnastics, weight-category sports) or endurance sports where people perceive “lighter as faster”

  • History/or currently have an eating disorder, especially if the disordered relationship was triggered due to sporting performance.

It is important to note that it is not just females who are affected. RED-S was previously termed the female athlete triad but became more apparent that males can also experience RED-S. Reductions in body mass, alterations to body composition and the drive to be at peak performance when under-fueling can negatively impact testosterone levels, recovery and performance adaptations.

Everyone is different and one person’s experience, side effects and risk factors may be different from the next person. Regardless, medical advice is recommended for recovery and a treatment plan that is tailored to you.

What are the types of RED-S?

There are two variations of RED-S, although both displaying similar symptoms and characteristics, the intentions behind the two vary greatly.

1.Voluntary RED-S

2.Involuntary RED-S

Voluntary RED-S:

RED-S might develop due to a desire to change body composition and lose weight because they have either been encouraged to do so by my coaches or fellow athletes with the belief that this will help with performance or there is a pressure from society (2)

This might result in training more often and more intensely, whilst reducing nutritional intake. Nutritional intake becomes compromised and insufficient to meet the demands of training, resulting in severe consequences, especially as some athletes are already at a low weight to meet the requirements of their sport.

Involuntary RED-S:

Some individuals can be diagnosed with RED-s or display symptoms and aren't athletes. These individuals are often those with busy, active lifestyles, regularly participating in physical activity and as a result, are unaware of the high levels of energy they are expending daily.

Involuntary RED-S can be treated through education about their daily nutritional requirements (unique to everyone), suggesting ways to supplement training with sufficient energy to fuel performance and providing simple ways to ensure nutrition is ready and available for busy schedules.

How can I overcome RED-S?

RED-S is an incredibly complex and individualised condition characterised by a reduction in energy availability. Gaining an understanding for what you believe are your potential triggers, thought processes and type of RED-S will help you to seek the correct support. It is important to reiterate that everyone is unique and medical support is the number one priority on your road to recovery. You can read about treatment for RED-S here. Abi Woodliffe-Thomas

Abi is a personal trainer and is working towards becoming an exercise nutritionist. Follow Abi on Instagram at @Happeitite_for recipe inspiration and nutrition tips!



[1] British Journal of Sports Medicine 2017; 51 1509-1509 Published Online First: 17 Oct 2017. doi: 10.1136/bjsports-2017-098421

[2] McGregor, R., 2021. Risks. [online] Trainbrave.org. Available at: <https://trainbrave.org/risks/>


Talia Cecchele Nutrition is a team of registered dietitians specialising in eating disorders and disordered eating. We aim to bring balance back to nutrition, help you to break free from food rules and find food freedom. To enquire about private consultation please fill out a contact form.


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