What is Relative Energy Deficiency in Sports (RED-S) and do you have it?

RED-S was previously known as the Female Athlete Triad, which Drinkwater et al. defined as ‘the combination of disordered eating and irregular menstrual cycles eventually leading to a decrease in endogenous estrogen and other hormones, resulting in low bone mineral density.” The diagram below is a simplified view of the two major complications of relative energy deficit.

Updated research has shown that the deficiency of energy available affects more than menstrual function and bone health. It affects multiple systems in the body, including but not limited to impairments of metabolic rate, menstrual function, bone health, immunity, protein synthesis and cardiovascular health in both men and women. Also, it can affect both athletes and recreational exercisers. RED-S has expanded the Female Athlete Triad with a broader spectrum of signs and symptoms that considers multiple systems in the body allowing us to diagnose the syndrome at an earlier stage so that we can prevent further development and future complications.

In the figure above we see the various problems that a patient may experience due to low energy availability. One of the most significant complications is bone health, potentially leading to injuries such as stress fractures, which develops in the later stages. The goal of an early diagnosis is to prevent such injuries, to catch the disease at an earlier state, and to allow early treatment to restore the normal function to the body. If you are concerned that you may be experiencing some of the listed signs and symptoms please contact Dr. Carfagno at the Scottsdale Sports Medicine Institute for a consultation.


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Mountjoy M, Sundgot-Borgen J, Burke L, et al Authors’ 2015 additions to the IOC consensus statement: Relative Energy Deficiency in Sport (RED-S) Br J Sports Med 2015;49:417-420.

Mountjoy M, Sundgot-Borgen J, Burke L, et al The IOC consensus statement: beyond the Female Athlete Triad—Relative Energy Deficiency in Sport (RED-S) Br J Sports Med 2014;48:491-497.

Drinkwater BL, Nilson K, Ott S, et al Bone mineral density after resumption of menses in amenorrheic athletes. JAMA1986;256:380–2.

Loucks AB. Energy balance and body composition in sports and exercise. J Sports Sci 2004;22:1–14.