Relative Energy Deficiency in Sport (RED-S), formerly known as the Female Athlete Triad, happens when an athlete expends more energy than they consume. The mismatch, subtle or extreme, between nutrition, rest, and exercise could have serious consequences for the athlete’s overall mental and physical wellbeing. Athletes have an intimate and complex relationship with energy consumption. One study showed that 69% of athletes think about the calories they are burning during exercise sessions, 65% worry about what they eat, 62% worry about having fat on their bodies and 61% believe that they are overweight. Of these athletes, around 67% were placed are medium to high risk of RED-S.
RED-S affects athletes of all genders, ages and abilities and can result in a premature end to a promising athletic career and poorer athletic performance as well as causing serious, life-long health consequences. Watching for warning signs and seeking treatment as soon as possible is important.
Relative Energy Deficiency in Sport vs Female Athlete Triad
In the 1990s, the Female Athlete Triad was first identified when medical professionals and scientists began to understand the effects of exercise on women’s health. The Female Athlete Triad was described as a complex interrelationship between menstrual dysfunction, decreased bone mineral density and low energy availability (with or without the presence of an eating disorder). Since then, with increased awareness and research, the term has evolved to be more inclusive and have a wider scope. It has been discovered that this syndrome is not limited to hormones regulating menstruation, but can also affect testosterone levels – meaning that it can affect both male and female health. Unfortunately, the negative side effects are not limited to bone mineral density and can include other serious consequences for the athlete’s health. For better inclusivity and to account for the wider range of symptoms, the “Female Athlete Triad” was changed to “Relative Energy Deficiency in Sport (RED-S)”; this disorder is not limited to female athletes and has a wider range of symptoms than a simple triad. Diagnosis and treatment can be challenging and is best handled by a multi-disciplinary team. Recovery and healing are possible.
Causes and Risk Factors for Relative Energy Deficiency in Sport (RED-S)
Relative Energy Deficiency in Sport is the result of having low energy availability for too long. Low energy availability (LEA) is when a person’s body does not have enough energy to maintain normal “day to day” physiological functions, i.e. the functions to keep us alive and well. To calculate someone’s energy availability medical professionals, athletes and coaches will look at how much energy someone takes in and how much they use. If the energy taken in is too low the athlete may start to notice feeling fatigued or tired all the time and a general decrease in their athletic performance.
Risk factors for low energy availability and the development of RED-S can vary from person to person and may evolve as more studies and more information is discovered. Currently, some well-established risk factors include:
- Consuming fewer calories or dietary changes
- Increasing energy expenditure (for example, increasing workout length or intensity)
- Eating less
- Always thinking about weight
- Disordered eating
- Disordered training
- Sport identity (certain sports place more emphasis on an “ideal” body shape or size)
- Changes in hunger hormones
- Perceived power dynamic between coach and athlete
Early Warning Signs of Low Energy Availability and Relative Energy Deficiency in Sport
Athletes understand that not every day of training or rest will be the same, as our bodies are constantly in a dynamic state of flux. However, training harder without increasing energy intake can result in a state of low energy availability, which will make training even less successful and leaves the athlete feeling constantly fatigued. This is because the body has limited energy and critical functions that keep us alive will get prioritized over exercise. The body’s trying to make us stop and rest, even if that seems counterintuitive – rest can make athletic training much more effective.
Like a car running out of gas, the body will give the athlete warning signs before coming to a juddering halt. Some early warning signs of low energy availability and possible development of RED-s include:
- Lingering colds or flu-like symptoms
- More injuries and injuries taking longer to heal
- Low mood
- Low energy levels or feeling tired all the time
- Irritability
- Reluctance to rest or eat more
- Preoccupation with body size or shape
- Self-blame or becoming very self-critical
- Denial about a possible problem
- A feeling the something is just “not right”
Tests for RED-S can be tricky, as no one factor points to a diagnosis, it is a combination of factors. However, medical professionals need to exclude other causes of endocrine disruption and check which hormones are being affected. Recommended tests for the diagnosis of RED-S include:
- For female athletes: follicle-stimulating hormone (FSH), luteinising hormone (LH), oestradiol, testosterone, pregnancy test
- For male athletes: testosterone, luteinising hormone (LH)
- For all athletes: full blood count (FBC), thyroid function tests, ferritin, vitamin B12, vitamin D, 9 am cortisol, prolactin
Side Effects of Low Energy Availability and Relative Energy Deficiency in Sport
The side effects of sustained low energy availability and the development of Relative Energy Deficiency in Sport (RED-S) can be serious. Evidence shows that they compound and worsen with time. Although some of the negative consequences of using more energy than consumed overlap or evolve, it is possible to group them into acute (short-term) and chronic (long-term) side effects. Each body is different, so an athlete may not develop all these problems; however, if any are present, it is advisable to seek medical advice.
Short-Term Side Effects
- Lower blood glucose levels
- Lower leptin levels
- Disrupted release patterns of hormones (like gonadotropin-releasing hormone, triiodothyronine, luteinizing hormone or cortisol)
- Reduced muscle protein production
- Decreased desire for sex
- Mood changes
- Fatigue
Long-Term Side Effects
- Changes in hormone production and release (including luteinizing hormone, growth hormone, estrogen/testosterone, ghrelin, insulin, cortisol and others)
- Reproductive health problems
- Decreased bone health
- Dyslipidemia
- Low heart rate and blood pressure
- Hypoglycemia (which can have extremely dangerous implications for the brain)
- Injuries
- Compromised immune system
- Low resting metabolic rate
- Poorer athletic performance
- Gastrointestinal problems
- Appetite reduction
- Development of eating disorders
Common RED-S Myths
The biggest myth surrounding RED-S is that it only happens to “other athletes”. Project RED-S, a site to support athletes with RED-S run by those impacted by it, emphasizes that anyone who exercises is an athlete and any athlete can develop RED-S. Other common myths include:
- Only athletes with an eating disorder are at risk for developing RED-S
- It is normal for athletes to lose menstrual cycles
- RED-S only happens to female athletes
- RED-S only happens to thin athletes
- RED-S only occurs in professional athletes who train much harder
- To have RED-S athletes need to be more ill, injured or struggling harder emotionally than “I” am
Treatment and Support
Myths block access to treatment and support. Do not assume that a person does or does not have an eating disorder or RED-S, if any of the warning signs match yourself or a loved one, reach out. RED-S has a better prognosis the earlier you reach out and any of the warning signs or side-effects might require medical attention, with or without a diagnosis of RED-S.
Treatment is challenging and requires a multidisciplinary team, such as can be found at Koru Spring. The team can include the coach, physiotherapists, dieticians, psychiatrists, psychologists and other medical practitioners. They work together to try and get the best possible outcome for the athlete’s physical and mental well-being.
