Relative Energy Deficiency In Sport

Relative Energy Deficiency in Sport, “RED-S” or simply “RED-S” is a clinically defined syndrome referring to the impairment of physiological function caused by a deficit in a person’s energy intake relative to the energy required to maintain optimal health, homeostasis, growth, the activities of daily living, and sport.  

Being in this state of relative deficit is often also referred to as being in a state of low energy availability (LEA). In this state, there is a lower than required amount of energy for the body’s normal physiological functions.

However, more recently the systemic nature and pathological consequences relating to low energy availability beyond menstrual dysfunction and poor bone health, as well as the fact that that these problems may also be present in males – has led to the more encompassing term of ‘RED-S’ being used to refer to this syndrome. 

Active men or women with disordered eating or with an eating disorder are at risk.

Disordered eating (DE) is a term that refers to a range of irregular eating behaviours but does not fit the full criteria to be diagnosed as a specific eating disorder.  The DE continuum can lead to clinical eating disorders (EDs), abnormal eating behaviours, distorted body image, weight fluctuations, medical complications and variable athletic performance. 

DE can include (but isn’t limited to) things like:  

• Chronic restrictive eating 
• Excessive fasting 
• Food-related anxiety 
• Skipping meals 

• Restricting entire food groups 
• Negative preoccupation with food 
• Negative preoccupation with weight and body image 
• Misuse of laxatives or diuretics 

Eating disorders (ie anorexia nervosa, bulimia nervosa, binge eating disorder, and others) are diagnosed according to specific and narrow criteria. The criteria can be found in the American Psychiatric Association’s  Diagnostic and Statistical Manual of Mental Disorders (DSM). 

Up to 70% of elite athletes competing in weight class or aesthetic sports (both male and female) are dieting with the intention of reducing weight before competition. 

From an energy balance standpoint, weight loss is only possible when you are in a calorie deficit, i.e. consuming fewer calories than you are using. On top of this, some type of disordered eating pattern often accompanies this weight loss attempt. Other times, mismanaged programming for rapid reductions in body mass/fat, or inability to track and match calorie intake with an extreme exercise commitments contributes to an energy imbalance. 

Younger athletes and teenagers are also a high-risk category. In addition to the energy demands of their sport, they also have higher energy requirements to support growth and physical development throughout maturation. 

Indications that you might be suffering from RED-S are highly individual but can include: 

Low body mass/low body fat, weight loss, lack of normal growth and development, menstrual dysfunction, recurrent injuries and illnesses, decreased performance, mood changes. 

There are various screening tools available for health professionals to assist in evaluating individuals at risk of, or with suspected RED-S such as the  RED-S CAT. 

Early detection is important in the diagnosis of RED-S, and a  high level of caution is warranted physique, weight class, lean body, and endurance sports. 

Now we understand what RED-S is, and it’s potential consequences are, a follow up blog will focus on how to avoid it.