RED-S syndrome – how to get out of it?

The RED-S syndrome (relative energy deficiency in sports) unlike the Female Athlete Triad, also affects men when it comes both to health and sport performance.

RED-s occurs when the availability of energy is too low to provide the right amount of fuel for maintaininig vital functions of the body (both daily duties and intensive training units.) The reduced body weight or reduced BMI aren’t are not necessarily a case with RED-s, as low energy availability is the most important for the syndrom to occus.

Energy availability is calculated is determined out of 3 factors: the expenditure related to physical activity EEE), the energy intake (EI), and the fat free mass (FFM).

It has been shown that energy availability of 45 kcal / kg FFM / day is optimal for maintaining normal physiological functions in women.

When the availability of energy is reduced  (via reducing the energy intake and / or increasing physical exertion) body tries to adapt through reducing its energy expenditure. This leads to imbalance in the endocrine, digestive, hematological, immune, skeletal, reproductive, cardiovascular and nervous systems.

Overtraining, increased mental stress, accumulated through excessive physical exertion and additional stressors in life, significantly affect the athlete’s health and performance. Very often they are accompanied by additional psychological and physiological symptoms, common in elite athletes.

RED-S also affects male athletes, although compared to women, identifying this syndrome is much more difficult and less studied. A positive correlation of exercise addiction (EXD) with ED symptoms, a clear negative energy balance and higher cortisol levels was also diagnosed. The risk of RED-S in this group of athletes is increased.

Low iron levels are very common in athletes with RED-S syndrome. A deficiency of this component may induce or result in low energy availability. Changes in the endocrine system include disruption of the HPG (hypothalamic-pituitary-gonadal) axis, thyroid function, leptin and ghrelin – appetite regulating hormones. There is also a decrease in insulin, IGF-1 and an increase in cortisol.

Already after 5 days of significant energy deficit in male athletes, a decrease in testosterone levels was noted. For women, low energy availability results in a disruption of the pulsed release of the GnRH hormone in the hypothalamus, which is associated with a disorder of LH and FSH secretion, hormones that stimulate estradiol and progesterone secretion. Automatically, the entire menstrual cycle in a woman is disturbed.

One of the complications of low energy availability along with a disturbed cycle is bone health deterioration. Reduced bone mineral density, altered bone microarchitecture and increased risk of injury and fractures have been demonstrated. Even short-term low energy availability has a destructive effect on the skeletal system in women and some men.

Risk assessment criteria

A new model of risk assessment criteria RED-S has been developed. It was recommended that athletes in the high risk category should not be allowed to participate in their sport, as this may pose a threat to their health and distance them from treatment. Athletes in the moderate risk category may participate in sport, but with supervision and a treatment plan provided.

The athlete’s RED-S risk assessment should be carried out regularly for up to 1-3 months.

How to get out of it?

Low energy availability (EA)

Reducing physical exertion and / or increasing energy supply is a major strategy for treating low energy availability. In practice, introduction of 300-600kcal / day into the current diet could help lead the athlete out of the RED-S syndrome. In addition, if possible, event slight reduction in physical activity or inclusion of an off day in the training plan may have a positive effect on the disturbed energy balance. Working with a performance nutrition should help with setting a track that will lead to both positive health outcomes and the not impaired and possibly improved sport performance. 

Menstrual disorders associated with low EA

Bone health

In women with anorexia without menstruation, weight gain restores bone formation and improves bone mineral density (BMD), but complete recovery may not be possible.

Psychological aspects