The Benefits of the Mediterranean Diet triathlete, didn’t always fuel his long runs like a two-time Ironman champion. Years before he won his first triathlon, as a cross-country runner at Stanford University, he’d sometimes go 24 to 48 hours without eating—and still head to practice.
“It was really, really bad,” he says. “But working hard is part of being an athlete, so it didn’t feel abnormal at the time.” Plus, he wanted to make the cut for the national team, and he thought losing weight would help him reach his goal. “I had a bigger, more athletic build than the other guys, and I didn’t think I was lean enough to be competitive.”
His restriction both worked and backfired. “I hit my peak lightness, but I was really weak and consistently injured for a year and a half.”
Jesse was right about one thing: This kind of food restriction—though perhaps on the extreme end of the spectrum—isn’t abnormal, unfortunately. Elite runner Mary Cain last year, explaining that her coaches wanted her to become thinner, and thinner, and thinner CA Notice at Collection Opinion piece last year, explaining that her coaches wanted her to “become thinner, and thinner, and thinner.”
While definitive numbers are hard to come by, reports estimate that upwards of 20 percent of athletes aren’t eating enough, and though many aren’t necessarily restricting on purpose or at the hands of a coach like Cain alleged, elite runners often under-fuel their bodies given their intense training plans.
Running Shoes & Gear Instagram: “RED-S or Relative Energy Deficiency in Sport needs to be talked about more,” she wrote. She tells Runner’s World her post was inspired by her own experience. “I was super strict about my diet and would cut out different food groups,” she says. “I didn’t have a period, and it took me a while to realize that wasn’t a good thing.”
What is Relative Energy Deficiency in Sport (RED-S)?
In the simplest sense, relative energy deficiency in sport, also known as RED-S, implies inadequate energy intake compared to the energy you need, a more inclusive version of the Is the Keto Diet a Smart Choice for Runners, defined by a lack of period, low energy availability, and bone loss.
Essentially, RED-S is a broader concept that acknowledges the complexity of the problem, says Anna Melin, Ph.D., an associate professor in sport science at Linnaeus University in Sweden. “Low energy availability affects males as well, and there are even very few female athletes who have all three aspects of the triad.”
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You don’t need to be super lean, either. “You’ll lose weight when you first increase your training load or lower your energy intake, but the metabolism adapts to prevent further weight loss,” says Melin. “You can have a normal body weight but still not have enough energy available for normal hormone production, protein synthesis, and recovery.”
And it’s important to note that there’s overlap between RED-S and eating disorders, but they’re not one in the same: “Low energy availability may be due to disordered eating, but it can also occur unintentionally, due to poor awareness of sport-specific fueling requirements,” says Clare Corish, Ph.D., R.D., an associate professor in clinical nutrition and dietetics University College Dublin, Ireland. Basically, low energy availability could cause an eating disorder, just as an eating disorder could cause low energy availability, but you could still have low energy availability and RED-S without having an eating disorder. “RED-S could be due to a lack of appetite, which happens with intense training,” adds Melin.
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RED-S Warning Signs and Health Risks
Cranny not only lost her period—both a symptom of RED-S and one-third of the Is the Keto Diet a Smart Choice for Runners—but she also felt irritable and tired and had a harder time recovering from workouts. “You start to lose joy and motivation,” she says.
“Running Shoes & Gear overtraining,” says Fabio Comana, MA, MS, a faculty instructor at San Diego State University and the National Academy of Sports Medicine. That means fatigue, mood changes, reduced performance, and increased injury. You may also experience a lower sex drive: “Low glucose availability suppresses the production of sex hormones in both females (estrogen) and males (testosterone) to save energy,” Melin says.
Either way, we need more education on the topicfor both athletes and overtraining, Comana suggests reducing your training volume by 50 to 70 percent—depending on how crappy you feel—for ten days without changing anything else. “If you feel recharged afterward, it’s an overtraining issue,” he says. But if your symptoms come back in two days, it could be RED-S. And if that’s the case, you should speak to a professional ASAP, because the long-term risks—osteoporosis, heart disease, muscle loss, reduced immunity, and depression—go way beyond a compromised career.
For a true diagnosis, you’ll need to get a blood test and bone scan. “We take blood samples to measure hormones—like cortisol, plus thyroid and sex hormones— and assess body composition and bone health,” Melin says. “Women should also see a gynecologist to rule out other causes of menstrual dysfunction.”
How to Prevent and Treat RED-S and Eating Disorders
Your treatment plan will depend on whether the root is psychological (an eating disorder) or behavioral (say, under-fueling without realizing it). “It can be hard to identify an eating disorder when you’re in the middle of it,” says Riley Nickols, Ph.D., a counseling and sports psychologist at McCallum Place Eating Disorder Centers in Missouri. “And sometimes a disordered mindset around food, training, or body image can be normalized in the context of sport,” making it even tougher.
Either way, we need more education on the topic—for both athletes and coaches. “Sports providers can be very well-meaning but misguided,” says Nickols. “They have good intentions but sometimes veer outside their lane of expertise.” So, unless your coach is also a registered sports dietitian or a doctor with formalized training setting goal weights, Nickols says he/she shouldn’t be setting weight targets.
In fact, calling in the right experts is a crucial piece of the recovery puzzle, whether it’s a sports dietitian, therapist, or both. “You should have a sports dietitian and psychologist with eating-disorder expertise on hand, much like you have a physical therapist on call,” Nickols says. “Don’t underestimate the complexity of the problem and overestimate your ability to solve it on your own.”
A Turning Point
Both Thomas and Cranny say they hit a crossroads when they realized their strategy wasn’t effective. Thomas rethought his approach when he didn’t make the cut for nationals, because quite frankly, “it didn’t work,” he says.
And Cranny says a series of stress fractures made her realize the reality of her restriction. “It was a huge wake-up call,” she says. “It took years to catch up to me, but beneath the surface, all the things I was doing were actually detrimental to my mental and physical health.” And it’s when she realized: “I need my body to be strong.” She eventually saw a nutritionist who helped her make small, manageable changes to her diet and a therapist who helped “challenge [her] ingrained thoughts and habits.”
To be clear, those ingrained thoughts—that certain foods are bad, that elite athletes need to look a certain way, that working yourself into the ground is part of the sport—can be hard to shake. As Thomas notes, people often see the relationship between hard work and success as linear: the more you put in, the more you get out. “But to get to the next level, you need to realize that the curve goes down at a certain point, and with more work, your performance suffers because you’re limiting yourself,” he says. “Once I found balance, I had so much more success.”
