Are You Under-Fueling Your Workouts?
Protecting athlete health and performance and 6 things you need to know about the new International Olympic Committee consensus statement on Relative Energy Deficiency in Sport (REDs)
Quick note: Today’s post is a bit heavy on the science but it’s an important topic that applies to everyone—not just elite or professional athletes. It applies to all people, of all ages and levels of physical activity, and across all sports. It’s particularly important for parents and adolescent athletes.
In recent years, there’s been growing awareness of the dangers of under-fueling when you exercise or train for sport. You may have heard the term Relative Energy Deficiency in Sport (or REDs) thrown around, but what the heck does it mean?
One (overly) simple way to think about is there’s a mismatch between energy consumed and energy burned through exercise and the activities of living (metabolism, circulation, breathing). Your body doesn’t have enough energy to do what it needs to do.
When you don’t eat enough to support your body’s energy needs, you can be in a state called low energy availability. This low energy state can lead to a cascade of changes in the body that affect not only your athletic performance but also your physical and mental health.
REDs can negatively affect pretty much every system in your body: metabolism, reproductive function, bone health, musculoskeletal health, immunity, gastrointestinal function, cardiovascular function, and mental health. It can lead to impaired well-being, increased risk of injury, and decreased sports performance.
You can find yourself in a state of low energy availability because of a high volume of exercise, intentional under-fueling (such as disordered eating patterns, eating disorders, or attempts to change your body composition), or unintentional under-fueling (you get so busy that you forget to eat lunch or you’ve cut food groups from your diet).
REDs was first defined and introduced in a 2014 International Olympic Committee consensus statement, which was then updated in 2018. Last week, the British Journal of Sports Medicine dedicated a whole issue to REDs, which includes the new consensus statement, three editorials, and six scientific reviews.
It’s a hefty update.
And for good reason. There have been nearly 180 original scientific studies on REDs in the last five years, giving scientists a more nuanced understanding of energy availability, the physiological effects of low energy availability, and REDs.
We often complain that science is slow and how it can take an average of 17 years for scientific research to be translated into clinical practice. What I appreciate most about these REDs updates is that they’ve provided practical tools and guidelines that clinicians, sports doctors, coaches, etc. can work with now to try to prevent and mitigate the negative health outcomes associated with REDs.
This is going to be two-parter.
In Part 1 (today), I’ll go over what’s in the new International Olympic Committee consensus statement on REDs.
In Part 2 (next week), I’ll cover what this updated information on REDs means for you and what we can do with this information.
So let’s get into it.
Takeaways from the Updated REDs Consensus Statement
I’m not going to go into detail about everything in the consensus statement. Instead, I want to highlight what I found were the most interesting findings and changes.
1. New Acronym
Relative Energy Deficiency in Sport is now referred to simply as REDs, not RED-S. I’ve heard REDs pronounced both “reds” and “red S” and I waffled between the two whenever I talked about it.
What’s interesting: While this is a small change, it should standardize things and that helps with education and dissemination.
2. Updated Models
To help people understand REDs, experts created two hub-and-spoke models—one that shows how REDs can affect different physiological systems and one that shows how REDs can affect performance.
In this update, they defined the spokes of each model more specifically (for example, “impaired energy metabolism/regulation” and “impaired glucose and lipid metabolism” instead of just “metabolic” consequences) and added new spokes to the physiological model (urinary incontinence, sleep disturbances, and reduced skeletal muscle function).
What’s interesting: Low energy availability is the “hub” of both models, emphasizing that the underlying cause behind REDs is inadequate energy. It also shows how low energy availability can exist on a spectrum of “adaptable” to “problematic” (the gradient arrows) depending on how long you’re in a state of low energy availability and number of other factors. (More on this next week.)
I also appreciate that the update recognizes that our physiological systems don’t exist in isolated silos. This update moves towards taking a more systems biology approach to understanding REDs—understanding how exposure to low energy availability can affect each body system, how the duration and magnitude of the energy mismatch influences the risk for REDs, how the systems can interact with each other, and how the interplay between an individual’s genetics, physiology, behaviors, environment can protect against REDs outcomes or make them worse.
It’s still a work in progress and a step forward.
3. Body Composition Guidelines
This is an important addition.
The focus on an athlete’s body composition—and the belief that there’s an ideal physique and build—can lead athletes, coaches, and the sports performance team to put undue emphasis on what an athlete’s body looks like as the key to athletic performance. These beliefs can create or perpetuate a culture where athletes feel like they have to have a thin, lean body in order to perform well. It can promote body dissatisfaction, disordered eating behaviors, and eating disorders, which are risk factors for REDs.
The update includes body composition guidelines that makes clear that body composition is just one variable that may impact performance. There’s no unique threshold that points to performance advantage and it does not contribute to early talent identification.
Yet, understanding among coaches and others around the role of body composition in performance and how to safely address these issues with athletes is low. In an interview on the BJSM podcast, Professor Margo Mountjoy, who led the team behind then consensus statement, asked why are coaches managing an athlete’s weight and body composition when it’s primarily a health issue?
What’s interesting: Body composition assessment is NOT recommended for athletes under the age of 18, except for medical reasons.
To me, this is super important because the body needs energy to support the maturation and development process. Plus, the influence of low energy availability during this period can lead to long-term physical and mental health concerns.
Experts emphasize that body composition should be treated as confidential medical information and the need to create psychologically safe sporting environment for athletes. They recommend that sports organizations establish formal protocols relating to body composition including continuing education for athlete health and performance teams and sports administrators like athletic directors. Addressing issues related to body composition should involve a multidisciplinary support team including a sports dietitian, sports physiologist/strength coach, psychologist, and sports medicine physician.
4. New Clinical assessment tool
It’s always been difficult to screen for and diagnose REDs, in part because it’s a diagnosis of exclusion, meaning that you have to rule out all other possible causes first. There’s no validated test to say you have it or not.
But it’s also because it’s really hard to measure and calculate energy intake and energy availability, especially when you’re not in a laboratory setting. Plus, the threshold where energy availability starts to get wonky appears to be different for different body systems and for men vs. women. It also may change over the lifespan.
In this update, they’ve created a new assessment tool designed to be used by athletic medical teams in real-world settings. It’s a three-step process: 1) an initial screening using existing validated questionnaires; 2) severity/risk assessment and stratification; and 3) physician diagnosis and treatment plan.
What interesting: Step 2. The risk stratification is based on signs and symptoms associated with REDs and they are grouped into primary and secondary indicators. The tiers are based on scientific evidence as well as whether or not it’s feasible for doctors or others to measure or identify that indicator (Is there a test available? Is it affordable?). Primary indicators score higher than secondary ones. They also include a list of potential indicators that don’t count for points in the assessment system but should raise a flag.
Points are added up and correspond to one of four zones:
Green: no to low risk of REDs
Yellow: mild risk
Orange: moderate to high risk
Red: very high/extreme risk of REDs
The best part? There’s a spreadsheet where you can enter an athlete’s information and it will calculate their risk for you. No math!
5. CARBS
Researchers have noticed that when people don’t take in enough calories, they often decrease their carbohydrate intake too.
What’s interesting: Researchers have found that not only can a downturn in nutrition lead to REDs-related outcomes, but insufficient carbohydrate intake can also accelerate the development of REDs outcomes and impair biomarkers such as those related to bone, immunity, and iron.
In fact, while reporting for my book, experts I spoke with told me that female bodies are more sensitive to declines in energy and carbohydrate availability. It’s something that needs to be investigated further.
6. Para Athletes
62 percent of U.S. para athletes preparing for the Paralympic Games tried to alter their weight or body composition as a mean to improve performance, a third had elevated scores when screened for eating disorders, and 44 percent of menstruating athletes reported menstrual dysfunction.
What’s interesting: Currently, the prevalence of REDs among para athletes isn’t known but there’s concern that these athletes might be a higher risk for low energy availability. We need more research.
I know this was a lot of dense information. Thanks for sticking with it.
Next week, I’ll get into what this information means for you—an active person, parent, coach, etc. If you have questions, leave them in the comments and I will try to answer them in next week’s newsletter.
If you found this helpful, please hit the like button below or share it with others!
More soon.
Christine
P.S. Check out Part 2 now!
I’m always curious about the implications here for post-menopausal athletes (and hopeful that we are part of the research) -- look forward to next week’s post!
Thanks for spotlighting this info--looking forward to the follow up post!