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

Healthy bones are the foundation to healthy running. Bones are strong, sturdy, and designed to tolerate a great amount of stress. In fact, bones get stronger from weight bearing. This is good news for runners, who put cumulative stress through their bones with each foot fall.

However, bones have their limits and require proper care. Here are key things all runners should know about their bone health.

Energy availability is a pillar of bone health. Energy availability (EA) is a measure of energy burned versus energy replenished per day. You have to eat enough calories to not only support the miles you put in, but to support your brain and bodily functions. If EA is chronically low from underfueling or overtraining, your body will start to drain your bones to get the nutrients it needs to keep you alive and moving. If you’re underfueling or overtraining, bones become weaker. EA can be quantified with this calculator (www.femaleathletetriad.org/calculators). Daily EA should be around 45 kcal/kg FFM/day and athletes should be eating a MINIMUM of 30 kcal/FFM/day for optimal bone health. Along with weaker bones, low EA can lead to fatigue, decreased performance, and increased risk of injury.

Sleep is by far the most important aspect of recovery an athlete can utilize, as lack of sleep is associated with weakened bones. Sleep deprivation can have significant negative effects on performance in endurance tasks and may also influence learning, memory, pain perception, cognition, immunity and inflammation. In a study of military recruits who were purposefully sleep deprived, it was found that they had a 5% reduction in bone mineral density in just seven days.¹ Sleep is the time your body takes to replenish and repair tissue that was stressed during the day. If your sleep is disturbed, your bones are at a greater risk of injury.

Nutrition is about quality and quantity. Runners need to eat enough food each day. (Remember EA?). Some runners find benefit in an individualized consultation with a registered dietician. (We can recommend some good ones!) Specifically, all runners should pay attention to daily calcium intake. Calcium is a major building block that keeps bones strong. Recent studies show that women who consumed less than 800 mg of calcium per day had nearly 6 times the rate of stress fracture than women who consumed more than 1500 mg of calcium.² Furthermore, fracture risk in runners is decreased by 62% for every additional cup of skim milk consumed per day.² Calcium’s best friend, Vitamin D, is responsible for calcium absorption. The worse a runner’s vitamin D intake, the longer it takes to recover from stress fracture.³ Thus, increasing daily calcium and vitamin D is a simple way to reduce fracture risk.

Listen up, ladies. Your menstrual cycle is a vital sign. That’s right: put it right up there with heart rate and blood pressure. A healthy, regular cycle is the cardinal sign that you are maintaining an appropriate EA, getting adequate nutrition, and protecting your bones. Female runners who have stopped menstruating are at a 4.5-fold increased risk of injury compared to regularly menstruating women.⁴ This is because monthly estrogen spikes with each cycle help protect bones against break down. Your period is a monthly signal of your health. If your periods become irregular or stop, talk to your healthcare provider for strategies to regain your cycle.

When it comes to bone health, prevention of fractures is best. If a fracture does happen, the road to recovery doesn’t have to be so bumpy when you’re armed with the right information to help prevent future bone health issues. Most importantly, the road ahead has the potential to be better than before. If you have questions about bone health or would like to be evaluated for a bone stress injury, don’t hesitate to reach out to our therapists.

1. Ben-Sasson, et al. Extended duration of vertical position might impair bone metabolism. Eur J Clin Invest, 1994
2. Nieves et al. Nutritional Factors That Influence Change in Bone Density and Stress Fracture Risk Among Young Female Cross-Country Runners
3. Serum Vitamin D Levels Are Inversely Associated With Time Lost to Bone Stress Injury in a Cohort of NCAA Division I Distance Runners
4. Heikura I. 2018

With less activity, athletes run the risk of defeating themselves mentally. A taper period is a crucial part of training that can make or break your upcoming race. Dr. Hannah DePaul reflects on her time swimming at the University of Michigan where she learned a lot about taper.

Two things that resonated with her: “The hay is in the barn and “Control the controllables.” Her coach would preach that all the hard you have put in is done, and now is the time to recover. Let the mind and body prepare for race day. You will not gain any fitness in the last couple of weeks leading up to your big race.

Some things are out of your control, such as who else is racing or what the weather will be like. Do not waste mental energy on those factors. Control what you have the ability to control…your mindset, attitude, and preparation. Focus on your race, trust your training, and good things will come. Having strategies in place ahead of time will help keep you mentally focused. So acknowledge the taper and embrace it!