What Nordic Skiers need to know about RED-S
By Lizzie Larkins
Lizzie Larkins is a full-time nordic coach for Montana State University. She graduated from the University of Vermont where she earned a Bachelor's of Science in Nutrition and Food Science as well as a certificate in Integrative Health. Lizzie was also a member of UVM's Nordic Ski Team and qualified for NCAAs in 2019 and 2020. She can be found exploring new areas on her mountain bike, drinking lots of coffee, cooking delicious food, running, backcountry skiing, and sending downhills on Nordic Skis. Lizzie is an advocate for the saying, "Happy Skiers go faster" and is stoked to be working with the next generation of nordic skiers!
Acronyms are ubiquitous and swirling throughout our media-savvy world especially in regard to nutrition and health. I have a new one for you: RED-S. Relative Energy Deficiency in Sport (RED-S) is the expanded nomenclature for the “Female Athlete Triad” as this condition does not apply solely to female athletes. The root of Relative Energy Deficiency in Sport stems from a significant imbalance between energy intake and energy expenditure.5 When athletes burn more calories than they are consuming for an extended length of time, their physiology reacts by influencing metabolism, menstrual cycles, bone mineral density, immune system, protein synthesis, cardiovascular health, and long term health.1
Before getting too far ahead of ourselves, let’s connect the dots to Nordic Skiing. As Nordic Skiers, our energy expenditure far exceeds that of the average human being. Training for this sport requires hours upon hours of aerobic and anaerobic training that engages the whole body. We also train in climate extremes throughout the summer, fall, and winter. Also, it is important to remember that we did not exit the womb with skis on our feet. First and foremost, we are human beings. We need our health as humans to excel as athletes. Think of it this way: if you are building a house, you do not want to build it on a flimsy foundation that will not be able to hold up your dwelling for a long period of time. We want strong foundations for our houses and for our performance as humans and athletes. Our daily eating pattern should contribute positively to our daily performance and build this strong foundation of health that will last far beyond our years of competing.4
Either intentionally or unintentionally, nordic skiers can find themselves in a long term energy deficit that has downstream effects on both health and performance. Training puts significant stress on the body and neglecting to consume adequate amounts of food adds even more stress. This starts to inhibit our ability to recover, adapt, and perform. The body has adaptive measures to postpone starvation, but this is where the symptoms of RED-S manifest. The equation for weight loss is to consume fewer calories than you burn, but this can cause long term health concerns if the athlete is depriving their body of essential nutrients while simultaneously still pushing it to perform. Concepts like “power to weight ratio” and “racing weight” are what athletes often think will improve their performance or appearance based on social norms in sport. These misconceptions around weight loss can lead athletes to underfuel given the demands of their training and ultimately, put them at high risk for RED-S. Misunderstanding weight loss and adequate sports nutrition contribute to the prevalence of RED-S among athletes and its inconspicuousness in the world of sport.4
Energy availability is having enough energy left over for normal bodily functions (like growth and development, circulation, regular menstruation) after accounting for exercise expenditure and calorie intake. In a less sciencey phrasing, it’s easy to forget all of the amazing yet intensive processes our body is carrying out and how much energy all of it requires. If we deprive our bodies of a certain threshold of calories, it has to prioritize some processes and shut others down.
Low energy availability is where energy intake is significantly less than energy expenditure from both exercise and physiological processes. It can be tied to the prevalence of eating disorders and disordered eating patterns across all sports. These behaviors manifest as a result of wanting to lose weight for aesthetic or performance which can become life-threatening if not addressed. Whether it is intentional or unintentional, athletes with low energy availability are more at risk for illness, fatigue, and deficiencies in their diet (like iron deficiency anemia which is common among endurance athletes, particularly females). This can pose problems with the musculoskeletal, endocrine, gastrointestinal, renal, and cardiovascular systems3. Sustained low energy availability can result in symptoms of RED-S like amenorrhea (absence of menstrual cycle), stress fractures, cold intolerance, dehydration, cardiac abnormalities (abnormal heart rates), fatigue, and impaired performance.2
Reversing the symptoms and onset of RED-S falls under the scope of practice of dietitians, sports medicine physicians, and psychologists. Halting training and addressing this condition is critical for avoiding its long term effects on the body. Awareness of this condition and its severity needs to spread among the athletes, the medical field, and the people who interact with athletes as support staff. Awareness will help all athletes prevent and resolve these issues so they can reach their full potential and fuel properly.
One of the key takeaways here is that as a nordic skier, you need to be aware that nordic skiing has some of the highest energy requirements of any sport. Because of this, fueling matters for your performance, your health, and longevity in sport. To avoid dancing with low energy availability, listening to your body and picking up on trends like suppressed heart rate, an unshakable case of the “tireds” or frequent sickness will allow you get ahead of this. Taking a rest day, eating foods high in quality and quantity, and seeking help if these trends persist are the best steps you can take to avoid the cascade of symptoms associated with RED-S.
Failing to meet the basic nutrition requirements, from a balanced, consistent diet has many negative impacts on health, wellbeing, and performance. My number one tip for eating to meet the demands of your training is to focus on timing. Have a general idea of what works for you on race days, morning training, afternoon training sessions, and double days. Make sure you eat a snack (optimally with protein and carbohydrate) within 30 minutes to an hour of training and a full meal within a window of 2-3 hours. Nourishment looks different for everyone, so find an eating pattern that works for your schedule, training demands, and taste preferences. Appreciate your own healthy, active body, and all it does for you. Give it the fuel it needs and enjoy the process of eating enough. It is the prerequisite required for supporting overall health and your active lifestyle!
Works Cited:
- Ackerman, K., Stellingwerff, T., Elliott-Sale, K., Baltzell, A., Cain, M., Goucher, K., . . Mountjoy, M. (2020). #REDS (Relative Energy Deficiency in Sport): Time for a revolution in sports culture and systems to improve athlete health and performance. British Journal of Sports Medicine, 54(7), 369-370.
- Brown University. (n.d.). Retrieved January 28, 2021, from https://www.brown.edu/campus-life/health/services/promotion/nutrition-eating-concerns- sports-nutrition/relative-energy-deficiency-sport-red-s
- Logue, D., Madigan, S., Delahunt, M., Heinen, E., Mc Donnell, M., & Corish, S. (2018). Low Energy Availability in Athletes: A Review of Prevalence, Dietary Patterns, Physiological Health, and Sports Performance. Sports Medicine, 48(1), 73-96.
- Long, J. (2020, June 26). Ep. 43: Friday flow: The paradox of weight loss for athletes. Retrieved June 29, 2020, from https://intheflownutrition.com/blog/weightloss
- Mountjoy, M., Sundgot-Borgen, J., Burke, L., Carter, S., Constantini, N., Lebrun, C., . . . Ackerman, K. (2015). The IOC relative energy deficiency in sport clinical assessment tool (RED-S CAT). British Journal of Sports Medicine, 49(21), 1354.