What is RED-S?

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There is a lot of discussion in the news lately about Relative Energy Deficiency in Sport (RED-S) and it is a topic that we at Adams Sports Medicine and Physical Therapy talk a lot about. Dr. Hannah DePaul and Dr. Katie Noble spend time educating high school cross country and track teams about how to be healthy and fast. We respect and admire Mary Cain and other women who have come forward with their personal struggles with RED-S. RED-S has dangerous, long-term consequences to the health of both female and male athletes. As Mary Cain highlights, in order to navigate the complexities of sport, body image and self-worth – the support and guidance an athlete has is critical to avoid the disorder. 

So what is RED-S? It’s having an inadequate amount of energy to support bodily functions for optimal health and performance, which can lead to serious health and performance consequences (see diagram below).1 When runners don’t eat or recover enough to support training, an energy deficit is created. When this energy deficit persists, an athlete will experience decreased performance, strength, and endurance and has increased risk of depression and physical injury. In a culture that often glamorizes #norestdays, young athletes need to be protected from developing habits that feed this disorder.

For women, RED-S can lead to menstrual dysfunction, which weakens bones and can lead to fractures. This is especially concerning in young athletes, as teens are developing peak bone mass that they will rely on for the rest of their lives. Periods are a barometer of overall health and if it’s lost, an athlete should seek medical help. Losing a period from training is never normal. For men, low testosterone can lead to thinning bones. While the signs of low testosterone aren’t as obvious as a lost menstrual cycle, knowing the risk factors for RED-S can help male athletes stay ahead of it. 

Historically, the culture of distance running has included a “thinner is faster” ideal. Research now proves that this thinking is dangerous to health and performance. A recent study found that male runners who responded “yes” to the statement “being thinner means being faster” were more likely to have low bone mineral density and an increased risk of fractures.2 A runner’s thoughts and beliefs about body image has real effects on physical health. There is no truth that the lightest runner is the best runner. The best runner is well-supported, well-rested, well-fueled, and wisely trained. 

Nutrition and sleep also play a huge role in preventing RED-S. A study found that women who consumed less than 800 mg of calcium per day had nearly 6x the rate of stress fracture than women who consumed more than 1500 mg of calcium.2   It’s shown that sleep deprivation can lead to bone loss.3 

RED-S isn’t just a physical health issue, it’s a cultural problem with sport. The culture of a sport and team can bring out the best in a runner or can be toxic to well-being. Breakthrough performances elevate sport and inspire humanity. The future of the sport lies within young athletes. Coaches, health care providers, parents, and everyone within an athlete’s support system has a responsibility to foster performance without sacrificing an athlete’s long-term physical and mental health. 

  1. De Souza MJ, Nattiv A, Joy E, et al. Br J Sports Med 2014;48:289.
  2. Tenforde, Adam & Fredericson, Michael & Sayres, Lauren & Cutti, Phil & Sainani, Kristin. (2015). Identifying Sex-Specific Risk Factors for Low Bone Mineral Density in Adolescent Runners. The American journal of sports medicine. 43. 10.1177/0363546515572142. 
  3. Tenforde AS, Sayres LC, Sainani KL, Fredericson M. Evaluating the relationship of calcium and vitamin D in the prevention of stress fracture injuries in the young athlete: a review of the literature.” PM R. 2010;2(10):945-949. Article Summary on PubMed. (http://www.ncbi.nlm.nih.gov/pubmed/20970764)
  4. Ben-Sasson, et al. Extended duration of vertical position might impair bone metabolism. Eur J Clin Invest, 1994