The REDs-Hormone Connection by Macy Davis
Thank you to Macy Davis, the Center for Active Women’s wonderful intern, for today’s post! Macy is a senior at Grant High School and will begin her collegiate volleyball career at Macalester College in September 2026.
In 2018, sixty-seven percent of NCAA athletic trainers working in America had never heard of REDs—an alarmingly high percentage, given the prevalence of REDs in athletes. Relative Energy Deficiency in Sport (REDs) describes what happens to health and performance when an athlete does not eat enough to meet their body’s needs. Its common underlying causes are disordered eating and under-eating, often resulting in menstrual dysfunction and decreased bone mineral health.
REDs affects a multitude of body systems, including the reproductive and cardiovascular systems and gastrointestinal and hematological function. REDs also has detrimental effects on the body’s energy and metabolism regulation as well as striated muscle function. This has significant implications as to the risks of athletes being pushed, or pushing themselves, past their limits, causing them to be in a calorie deficit and contributing to REDs. Over time, REDs leaves their bodies weak and prone to injury.
There is little doubt that REDs affects hormone levels; however, it must also be noted that estrogen changes may also interact with REDs. In considering the effects of estrogen on the body, it is clear that REDs and low estrogen can have similar impacts. Eating disorders rise at times of changing hormones, such as puberty and perimenopause. It is relatively widely known that hormone changes, particularly in estrogen, bring menstrual changes or disruptions in their wake. The strong correlation between secondary hypothalamic amenorrhea, commonly known as missed periods, and an injury strong enough to prevent an athlete from practicing or competing, is discussed much less.
As stated previously, REDs heavily contributes to the loss of bone density, which can lead to injury. Estrogen levels may also affect food intake. Hormonal changes that lead to weight fluctuations and changes in perceptions of body image are often a source of eating disorders. Even if an eating disorder does not occur, lower food intake can cause a calorie deficit, which can lead to low energy availability and REDs. In other words, estrogen and other hormones may contribute to REDs, while REDs can directly contribute to hormonal imbalances.
Hormones themselves have great impact on disordered eating and energy availability. For example, estrogen deficiency leads to low bone mineral density and a higher risk of injury. Disruption of the menstrual cycle, a symptom of REDs, co-occurs with estrogen deficiency. Once the body has low estrogen levels, bone density drops dangerously, and osteoporosis can set in. This relationship highlights a possible cycle of unhealthiness sparked by hormone changes, shifts in eating habits, and physical overexertion.
One can conclude that the relationship between REDs and estrogen, as well as other hormones, is like a cycle—one that must be broken to support these athletes. Women in sports everywhere need to be aware of the symptoms and negative impacts of REDs so that they can protect both themselves and their fellow athletes. It is equally important that medical professionals, trainers, and coaches have knowledge about REDs for the sake of their athletes’ mental and physical health and performance.
Works Cited:
Kroshus E, DeFreese JD, Kerr ZY. Collegiate athletic trainers’ knowledge of the female athlete triad and relative energy deficiency in sport. Journal of Athletic Training. 2018;53(1):51. doi:10.4085/1062-6050-52.11.29. https://pmc.ncbi.nlm.nih.gov/articles/PMC5800729/
O'Donnell, Justine, et al. "Perspectives on relative energy deficiency in sport (RED-S): A qualitative case study of athletes, coaches and medical professionals from a super league netball club." PLoS ONE, vol. 18, no. 5, 3 May 2023, p. e0285040. Gale Academic OneFile, dx.doi.org/10.1371/journal.pone.0285040.
Willsky, Kate. "How do Reproductive Hormonal Changes Affect Eating Disorders?" The Washington Post, Jul 28, 2022. ProQuest, https://libproxy.pcc.edu/login?url=https://www.proquest.com/newspapers/how-do-reproductive-hormonal-changes-affect/docview/2695194134/se-2.
Witkoś, Joanna, et al. "Menstrual cycle disorders as an early symptom of energy deficiency among female physique athletes assessed using the Low Energy Availability in Females Questionnaire (LEAF-Q)." PLoS ONE, vol. 19, no. 6, 7 June 2024, p. e0303703. Gale Academic OneFile, dx.doi.org/10.1371/journal.pone.0303703.
