Relative Energy Deficiency in Sport

Relative Energy Deficiency in Sport: Everything athletes need to know

Relative Energy Deficiency in Sport (RED-S), is a disorder that affects many athletes and often goes undiagnosed for a long period of time. As of 2018, RED-S is the updated clinical model of this disorder of what was previously described as the “Female Athletic Triad” which was characterized by menstrual disorders, impaired food intake and decreased bone density.

The reason for the evolution of this clinical model in the RED-S model is the abundance of scientific data that show that low energy availability occurs in both female and male athletes and is associated with an extensive range of adverse health and athletic performance.

So what is energy availability?

The human body needs nutrition in the form of calories and nutrients in order to perform the various processes needed to support life. For the athlete, the caloric needs are increased to meet the body’s requirements both during and post training.

The term energy availability, then, refers to the caloric intake through food consumption minus the calories expended through exercise, divided by the person’s fat free mass. Using this equation we can assess whether an individual is in adequate, reduced or low energy availability.

Adequate energy availability: >45 kcal / kg FFM / day
Reduced energy availability: 30 – 45 kcal / kg FFM / day
Low energy availability: <30 kcal / kg FFM / day

Risk groups for low energy availability

Low energy availability is the outcome of not consuming the necessary calories to support both normal body functions and the hard training, and it can affect male and female athletes of all ages. In fact, it occurs with a particularly high frequency in certain sports in which low body weight may offer a competitive advantage. In these cases, athletes usually deliberately try to lose weight.

The athletes who are most at risk are:

Young athletes, as they go through a period of growth and development which is accompanied by high nutritional requirements that must be met for a healthy integration into adulthood.
High level athletes, as the competitive nature of the sport at their level and their strong discipline can lead them to extremes in order to achieve the optimal body composition for their sport. This situation may also be exacerbated by certain coaches who in some cases exert excessive pressure on body weight and nutrition issues.
Endurance athletes, such as road cyclists or marathon runners, as the common knowledge of low body mass is an advantage may urge them try to reach or maintain an extremely low body weight.
Athletes in aesthetic sports, such as gymnastics or figure skating, where body image and the emphasis on a lean appearance increase the risk.

RED-S can also occur unintentionally in any athlete, during cycles of increased training load where the diet has not been adjusted to the increased demands of the body.

How is health and athletic performance affected?

In a state of low energy availability the body adapts, giving priority to only certain physiological functions, bypassing some others, in order to conserve valuable energy. More simply we could say that the body of athletes with RED-S is like a mobile phone device that enters “Power Saving Mode”, shutting down some applications to conserve energy for the most important applications.

At first you may feel just early fatigue during your training. However, as the energy deficit intensifies, a real loss of strength and muscle tissue may occur as the body breaks down the skeletal muscles to gain energy and support more important bodily functions, such as heart function and respiration. If this condition persists for too long, the health effects become more severe and include: inability to achieve maximum bone mass in young athletes or an irreversible decrease in bone density in adult athletes.

The following is a summary of the potential health effects, all of which are related to performance in endurance sports:

Hormonal disorders: decrease in bone density
Metabolic disorder: decreased endurance performance
Bone health: increased risk of fatigue fractures
Impaired immune function: susceptibility to infection
Gastrointestinal dysfunction: reduced absorption of nutrients
Inability to concentrate: non-improvement despite regular training
Decreased neuromuscular coordination: risk of injury

Warning signs

As mentioned at the beginning of this article, RED-S often goes unnoticed, especially in the beginning, with the result that its adverse effects on the bones develop progressively. If you’ve experienced any of the following signs, it may be time to review your current practices:

Medical and physiological signs	Psychological and behavioral signs
Amenorrhea	Anxiety
Dehydration	Depression
Gastrointestinal problems	Feeling overweight despite low body fat
Hypothermia	Physical exercise in addition to that required for the sport
Heart abnormalities	Difficulty concentrating
Fatigue fractures	Continuous engagement with body weight
Overuse injuries	Continuous engagement with food
Significant weight loss	Avoiding situations and gatherings that involve food
Muscle cramps, weakness or fatigue	Use of laxatives
Dental problems	Use of slimming pills

Nutritional management

If you suspect you are experiencing RED-S, you should consult a dietitian with experience in the subject to examine your case, assess any disturbed eating patterns, and guide you in designing the right diet plan for your needs. Here are some helpful tips to prevent RED-S:

Limit weigh-ins to no more than once per week.
Realize that the leaner athletes are not necessarily the fastest or most competitive ones.
Evaluate your own abilities and do not compare yourself with other athletes. After all, the optimal weight for health and performance is different for everyone.
Realize that your health is more important than a potential competitive advantage, and without optimal health victory is even harder to accomplish.
Think of the calories as fuel for your performance! Before embarking on an exhausting diet, consult a dietitian who can provide personalized recommendations for achieving optimal weight and enhancing athletic performance.