Relative Energy Deficiency in Sports (RED-S)

Welcome back, Bestie! It’s good to have you. I’m looking forward to chatting about athletes and relative energy deficiency in sports (RED-S) syndrome today. You might not know this but I, myself was an athlete back in the day! I was a sprinter on the track and field team in college and part of the club gymnastics team at my university, as well. I am not only experienced as an athlete but in treating athletes, too, so let’s dive right in.   

What is RED-S?

RED-S is a syndrome in which an athlete’s performance and health are negatively affected by a lack of adequate nutrition. Typically, the athlete is not consuming enough food or getting enough nutrients to provide the energy needed to meet the demands of their training activities. RED-S can affect folks of all genders and ability levels. Let’s talk about some of the impairments that can result due to RED-S:

-       Bone health impairments: Typically, physical activity is a fantastic way to strengthen bones. Weight-bearing activities, such as walking, running, tennis, etc, are great ways to build bone density and ensure healthy bones. However, in cases of low energy availability, estrogen (in females) or testosterone (in males) may be reduced (1,2). Estrogen and testosterone both play vital roles in bone health. As we’ve discussed before, osteoporosis is common in post-menopausal females due to the reduction in estrogen, so it makes sense that reduced estrogen in female athletes would impair bone health. This is especially worrisome because the ages during which young athletes are at their peak athletic performance are also the years when peak bone mass is established (between the ages of 10 and 20), so experiencing poor bone health due to RED-S can have lifelong effects. In females, bone lost during this time cannot be replaced and this may increase the risk for osteoporosis later in life (3).

-       Reproductive health impairments: In males, RED-S may result in decreased levels of testosterone and low libido. In females, it can lead to missed or absent periods (amenorrhea). The body sort of shuts off the menstrual cycle because if it doesn’t have enough energy to keep up with the demands of the athlete, it definitely doesn’t have enough energy to nourish a fetus. Of course most young, female athletes aren’t looking to get pregnant, but it is important to understand the evolutionary reason for these symptoms. Note that it is never normal to experience amenorrhea as a part of training and if you are experiencing this, you should talk with your medical provider to determine what is causing your symptoms (there are a ton of reasons for amenorrhea aside from RED-S).

-       Decreased immunity: There is limited research on how RED-S affects immunity, but one study showed increased rates of upper respiratory infection and gastrointestinal (GI) tract illness in athletes with low energy availability (4).

-       Slowed metabolism: Metabolism is dependent on a bunch of factors. We don’t have time to get into everything that affects metabolism, but I do want to mention a hormone called leptin. Leptin is not entirely understood, but it is thought to regulate long-term energy balance and metabolic rate. It has an influence in appetite, satiety, and more. In fasting, leptin levels drop significantly. Not only does leptin influence metabolism, it also has links to menstruation and bone health (are we seeing the connections?!).

-       Reduced heart health: It is common for slower-than-normal heart rates to be observed in folks with RED-S. Also, estrogen has a positive effect on the cardiovascular system. It has been shown to aid in blood vessel health and cholesterol (5). The reduction of estrogen in females with RED-S can reduce the positive impacts of estrogen on the cardiovascular system.

-       Altered psychological health: RED-S can result in moodiness, depression, anxiety, and irritability. In some cases, folks with RED-S may suffer from an eating disorder (6).  

-       Impacted athletic performance: RED-S syndrome can cause decreased strength, poor coordination, and decreased concentration levels. It can also impair judgment, reduce endurance, and reduce one’s response to training (1). There is an increased risk for injury in athletes with RED-S syndrome and it is a condition that should be taken very seriously.

Is RED-S the same as the Female Athlete Triad?

You might be more familiar with the Female Athlete Triad (FAT). This syndrome is a subset of RED-S and describes a more specific population (females). This is a very common syndrome affecting young, female athletes, and as the name suggests, it is made up of three separate conditions. These conditions include disordered eating, osteoporosis, and menstrual dysfunction. The FAT really describes the interrelationship between these three conditions.

How are RED-S and FAT treated?

RED-S and FAT are serious medical conditions that can have lasting effects. It is important that athletes with these conditions receive appropriate medical care. Intervention should involve a treatment team. The athlete’s coach, parents (if the athlete is a minor), psychologist, dietitian, physical therapist, and medical doctor should all play a role in the treatment plan. In these types of cases, prevention is key.

Folks that are involved in the training of young athletes of any level should be knowledgeable about this topic and discuss it with their athletes. Also, keep in mind that disordered eating is different than an eating disorder. Disordered eating can include restrictive eating, inflexible eating patterns, and dieting and it can be more difficult to recognize than an eating disorder.

Athletes with RED-S or FAT should start by decreasing activity levels slightly and increasing energy intake slightly, until an appropriate balance is restored. Some medical providers may decide oral contraceptive pills are appropriate for their female patients in order to help restore estrogen levels. Finally, weight-bearing exercises should be prioritized in order to increase bone density and bone health.

If you’re an athlete, share this information with your athlete besties because chances are, someone needs to hear this today! It is more common than you might think. Thanks for hanging out and see you soon.

XOXO,

Your Pelvic Bestie

References:

1.     Narla A, Kaiser K, Tannock LR. EXTREMELY LOW TESTOSTERONE DUE TO RELATIVE ENERGY DEFICIENCY IN SPORT: A CASE REPORT. AACE Clin Case Rep. 2018 Nov 1;5(2):e129-e131. doi: 10.4158/ACCR-2018-0345.

2.     Rooks, Yvette; Corwell, Brian N.. Current Opinion in Orthopaedics: April 2006 - Volume 17 - Issue 2 - pp 149-154

3.     Pantano KJ. Strategies used by physical therapists in the U.S. for treatment and prevention of the female athlete triad. Phys Ther Sport. 2009 Feb;10(1):3-11.

4.     Mountjoy M, Sundgot-Borgen JK, Burke LM, Ackerman KE, Blauwet C, Constantini N, Lebrun C, Lundy B, Melin AK, Meyer NL, Sherman RT, Tenforde AS, Klungland Torstveit M, Budgett R. IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. Br J Sports Med. 2018 Jun;52(11):687-697.

5.     Knowlton AA, Lee AR. Estrogen and the cardiovascular system. Pharmacol Ther. 2012 Jul;135(1):54-70. doi: 10.1016/j.pharmthera.2012.03.007. Epub 2012 Mar 28.

6.     Pensgaard AM, Sundgot-Borgen J, Edwards C, Jacobsen AU, Mountjoy M. Intersection of mental health issues and Relative Energy Deficiency in Sport (REDs): a narrative review by a subgroup of the IOC consensus on REDs. Br J Sports Med. 2023 Sep;57(17):1127-1135.  

*The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a qualified health provider regarding any questions you may have about a medical condition or health objectives.