As a significant person in an athletes life, you play a key role in their support system. You can help by educating yourself about RED-S, how to spot the early warning signs, and where to find support. Here's what we think you need to know.
RED-S stands for Relative Energy Deficiency in Sport and is exactly what the name implies: a shortage of energy available to keep up with the demands of exercise, on top of essential daily functions (e.g. growth, respiration and digestion).
The term ‘low energy availability’ is used to describe the negative balance (whether intentional or unintentional) between energy intake and expenditure (i.e. food consumed vs physical exertion). In the face of sustained low energy availability, the body goes into 'energy saving mode' which negatively affects almost every system in the body. One concerning effect of RED-S is suppression of the reproductive system (which can result in irregular of missing periods among females), but RED-S can affect any athlete, of any age, gender or level, size or weight and carries serious long-term health and performance implications.
As someone who supports an athlete, we’d recommend getting to grips with the signs and symptoms, alongside common causes and how you can play your part in prevention (below).
Almost any athlete, dancer or exerciser of any age, gender, level, ability or weight can be at risk of RED-S - from recreational runners to Olympic gymnasts. However, athletes from endurance sports or those which promotes a low body weight (e.g. for aesthetics or performance) tend to be at the greatest risk for two main reasons.
1) Endurance sports, by nature, demand a lot of energy which can easily be underestimated
2) Where there are pressures to look a certain way or achieve a certain weight, athletes are more likely to manipulate their food intake in order to gain a perceived performance advantage
Certain sports (such as long distance running, climbing, dancing, gymnastics, rowing and cycling etc) involve both a high training load and pressure regarding body composition, making these athletes most susceptible to RED-S.
Put simply, RED-S is the result of consistently consuming insufficient calories for the amount of energy expend, either intentionally or unintentionally. There are many different factors which can contribute to this, including:
- Intentionally restricting calories – e.g. to meet body composition goals or lose weight
- Unintentionally underestimating the energy requirements of training/competition
- Not matching an increase in training with a corresponding increase in calorie consumption
- Lack of appetite or gastrointestinal distress (upset tummy) leading to less food consumption
- Moving to university and increasing active travelling on foot/bike more, having to cook own meals, change in training types/frequency/intensity, wanting to focus on being ‘healthier'
- As a result of disordered eating behaviour or a clinical eating disorder (see below)
Often, the true cause can be difficult to determine since disordered eating or exercise behaviours are likely to be kept secret and are commonly accompanied by denial. Regardless of the cause, it's important to confront this early on since chances of recovery are significantly increased with early identification and treatment. Read some tips on how best to approach an athlete below.
The symptoms of RED-S often overlap with those of the 'Female Athlete Triad', which as the name suggests, focuses only on females with three inter-related issues: low energy availability, amenorrhea (missing periods) and low bone density. As research evolved, low energy availability was found to not only impact males as well as females, but those who don’t necessarily define themselves as ‘athletes’ too. And, whilst menstrual function and bone health are often impacted by low energy availability, the consequences extend to a far wider range of physiological and psychological components across all genders. So, in 2014, the International Olympic Committee introduced RED-S as a more inclusive term to describe the far broader range of individuals impacted by these multidimensional consequences.
Many athletes, parents, friends and teammates of athletes will never have even heard of RED-S, which adds to the difficulties of detecting it. In some cases, the athlete you care about may have experienced a decrease in their weight, energy levels, or performance, but in others, it may not be as externally visible. You can read a list of common signs and symptoms here.
It could be a case of listening out for things the athlete may say about their eating or exercise regime. Depending on how close you are to the athlete you're worried about, you could try to look out for an increase in the duration/frequency/intensity of their training. While the athlete's eating habits may seem normal, it could be a case of over-exercising or cumulative stress in other areas. If you have a general idea about the typical duration/frequency/intensity of their exercise sessions, you can monitor whether these number seem to be creeping up and up.
As an observer, it can be difficult to distinguish between ‘athletic’ and ‘disordered’ eating, but there are a few differences to look out for. Athletic eating is more likely to be directed towards performance improvements, rather than weight loss or altered body composition. There is more emphasis on what needs to be eaten to maintain health and performance, than what is forbidden or unnecessary. Athletic eating habits tend to 'relax' or 'normalise’ in the off-season and in retirement, while disordered eating habits are often maintained or even exacerbated during periods of rest - perhaps for fear surrounding weight gain.
Disordered eating behaviours can include:
- Sticking to a rigid routine surrounding food and exercise
- Feeling anxious about eating around others or going to new places to eat
- Attaching guilt and/or shame to eating certain foods
- Generally being preoccupation with food, weight and body image in a way that negatively impacts quality of life
- Feeling out of control around food
- Using exercise, food restriction or fasting to ‘make up for’ eating ‘bad’ foods
- Exercising to ‘earn’ food
- Restricting food intake on rest days
The difference between disordered eating and a clinical eating disorder (like anorexia or bulimia) surrounds how much the disordered behaviours disrupt someone’s daily life and impair their ability to function. Clinical eating disorders are diagnosed according to specific criteria surrounding body weight and eating behaviours. Many people experience some degree of disordered eating which falls short of an official diagnosis.
It’s important to look hard for the presence of disordered eating behaviours, not simply because they can quickly develop into more serious conditions, but also because they can be difficult to detect – especially among those determined to mask the issue.In many cases, disordered eating is a pre-cursor for a clinical eating disorder so it is still crucial to identify and monitor these with help from a medical professional.
Any level of disordered eating can have a significant impact on an athlete's overall health and performance. If you suspect your athlete may exhibit any of the behaviours above, try to open up a discussion quickly, directly and confidentially and encourage them to seek medical support. It’s incredibly hard to get an accurate idea of prevelance but current best estimates suggest eating disorders are twice as likely to develop among athletes than non-athletes (Torstveit et al., 2008).
Since causes of low energy availability range from unintentional on one end of a spectrum, to a diagnosable eating disorder on the other, there are multiple reasons that an athlete may be in a state of RED-S. If they aren't exhibiting any signs of disordered eating, it could be that the athlete is simply misjudging their nutritional requirements.
Though it may be hard to believe when someone seems to eat a great deal, it can incredibly easy to underestimate the nutrition required to match the demands of training. This isn't helped by the countless social media icons and bloggers who promote restrictive eating behaviours and provide misguided information on the internet.
An increase in training volume or intensity (when not matched with an increase in caloric intake) can lead to RED-S over a period of time. Even adding in extra drill sessions, strength and conditioning work, extended warm-ups or cool-downs can contribute to decreased energy availability when these activities are not compensated for with the right nutrition.
Thankfully, unintentional under-fueling should be relatively easily resolved once an athlete is armed with the right information. If you think this could be the cause of your athlete's issue, we strongly advise seeking help from a dietitian. Visit our resources page for recommendations.
A word of caution: Even unintentional under-eating can develop into something more intentional overtime. If, for example, the negative energy balance results in weight loss which brings about a short-term performance benefit, it can perpetuate a desire to maintain this weight, or lose more.
RED-S is typically diagnosed by a sports specialist via blood tests and an assessment of an athlete's relationship with training and nutrition. Unfortunately, there is often a gap in knowledge about RED-S within general medical practice, which may make it harder to diagnose and treat. However, it is essential that other medical conditions that may cause similar symptoms are ruled out and you can read our advice on getting the most out of your appointment here. It is extremely important that female athletes with an irregular or absent cycle have this investigated as a matter of priority.
Diagnosing, preventing and monitoring RED-S is made yet more challenging by the fact there is not one, definitive “test” to confirm if someone has, or is at risk of developing, RED-S. However, whilst every individual is unique, there are a number of common signs to look out for.
Specific blood tests are the “gold standard” when it comes to screening for RED-S. However, obtaining a set of the right blood tests are typically tricky to attain via a regular practitioner. Fortunately. there is a RED-S screening blood test, designed by RED-S medical specialists, that includes all the essential markers to assess the likelihood of low energy availability. You can find them here and the results can be taken to your first appointment with a RED-S specialist to save time and money further down the line.
Ultimately, determining whether an athlete is experiencing RED-S involves looking at the bigger picture. Their physical and mental health, training and nutrition all need to be considered but other tools, such as a DEXA scan (to establish their current bone health status) may be suggested. Find our recommended RED-S specialists here.
Unfortunately, many athletes who suffer the consequences of RED-S may initially experience the desired outcome (i.e. weight loss, a change in aesthetic or a performance advantage). As a result, it can be easy to confuse correlation with causation. This may fuel the fire to maintain the unhealthy behaviours behind the achieved outcome and push past the warning signs until they become a far bigger issue. By this point, the behaviours may well be ingrained and can be difficult to change without psychological support. Find a list of trusted psychology specialists with RED-S knowledge here.
Ideally quickly, directly and in confidence. When you open up the conversation, remember that RED-S can be caused by a number of reasons ranging from simply underestimating the nutritional demands of their activities, to intentional calorie restriction.
You could start by asking how they are, or expressing concern about a particular event. For example, “I'm just checking everything's ok? I’ve noticed you haven’t joined us for dinner lately. Do you want to talk about it?”. Or, “Was your period missing again this month? Do you need help figuring out why that might be?”.
It’s important not to appear ‘accusatory’ when it comes to intentional calorie restriction. If this is the case, the athlete may well be in denial or afraid of judgement from others. Instead, we suggest you try to reassure them that you understand by reminding them how athletes who train as hard as they do often need extra nutritional, medical or psychological support. Then you could ask if they’d be open to seeking some or investigating things further.
Remember, it’s not your job to diagnose anything or provide nutritional or medical advice. What you can do, is be there for your athlete and listen to their concerns in an open, non-judgemental way, while helping to direct them towards professionals who can help. Sending them the link to this website could be a good place to start 😉.
While disordered eating may or may not be a factor in your athlete's RED-S related issued, please bear in mind that eating disorders are serious and potentially very dangerous conditions that will require specialist support. Find more advice on this here and here.
With the right support, depending on the severity of the case, how long the athlete has been in a state of RED-S and a wide array of individual differences, most effects of RED-S should be reversible. These can include fatigue, poor performances, recurring illness or injury, amenorrhea, alongside many psychological symptoms such as disordered eating, irritability, depression and difficulty concentrating.
Bone health status however, can be a major cause for concern. It’s estimated that 60-80% of lifetime bone mass is formed by age 18 and peak bone mass by 26-30. In the long-term, the potential implications of RED-S include an inability to reach peak bone mass for young athletes and irreversible bone loss for older athletes. Importantly, where menstrual dysfunction is concerned, for every year an athlete spends in a state of amenorrhea (without a period), bone mass is estimated to decrease by 2-6%. This is just one reason why prevention and early detection of RED-S is so important.
Eric Stice, Kelsey South & Heather Shaw (2012) Future Directions in Etiologic, Prevention, and Treatment Research for Eating Disorders, Journal of Clinical Child & Adolescent Psychology, 41:6, 845-855
Torstveit, M.K., Rosenvinge, J.H. & Sundgot-Borgen, J. (2008). Prevalence of eating disorders and the predictive power of risk models in female elite athletes: a controlled study. Scandinavian Journal of Medicine & Science in Sports, 18, 108-118.
Wherever possible, the information and advice offered on this site is based on the leading scientific research to date. Although the aim is to provide you with some support and advice, this resource is no substitute for the diagnosis or treatment from a medical professional. Head here to find them.