An earlier version of this story was originally published in The Epic.
Student athletes balance a lot. Some are running early morning laps with teammates before heading to class; some are weight lifting several times a week on top of school and a social life. Some may skip snacks or meals when they’re busy; others may feel pressured to become leaner and will restrict food. At first they’re a little tired. Over time, they become extremely tired. Some of them will even miss their periods.
For some of these young athletes, the chronic, bone-deep fatigue and absent menstrual cycles could be a symptom of Relative Energy Deficiency in Sport, or REDs, a largely invisible condition that poses dangerous health consequences.
Cases of REDs are associated with student athletes who have overtrained and haven’t eaten enough calories to improve their recovery. It’s estimated that this impacts 15% to 80% of athletes, according to a study in the British Journal of Sports Medicine. This condition can affect athletes of any gender, though it’s primarily seen in women. Apart from irregular periods and exhaustion, athletes with REDs can also experience mood swings or depression, difficulty concentrating, hair loss and feeling cold all the time.
Experts say that increasing awareness of REDs, creating healthy training environments and promoting proper nutrition is critical for ensuring long-term well-being. Better understanding of this condition, and how to keep an eye out for signs is not only important for student athletes, but for any coaches and support staff as well.
“This season in football, we had a student who felt extremely tired all the time, but didn’t know why,” San Jose-area football coach and PE teacher Joseph Luo said. “It turned out to be low energy availability, as his body started to shut down from not having enough calories. He had to get enough rest, rehydrate and take proper care to recover.”
Recovery looks different depending on the severity of REDs. For some, returning to normal function may take a few months, while for others, particularly those who’ve been underfueling for a while, it can take more than a year to restore hormonal balance, metabolic balance and bone health. Due to the varying degradations of severity, diagnosing REDs can be complex.
“There aren’t any singular diagnoses, and you have to look at a combination of factors, indicators and context to diagnose someone holistically,” said Toni Gist, a clinical assistant professor of food science and nutrition at University of Illinois Urbana-Champaign. “Often, these symptoms are hidden as it might be shameful to the person.”
Poor performance isn’t the most concerning symptom — athletes are more likely to struggle with preventable injuries. Inadequate nutrition can lead to repeated stress fractures, muscle sprains, tendonitis and slower recovery. Female athletes risk low bone density, increasing the risk of fractures and osteoporosis. REDs can also destabilize hormones and weaken the immune system.
Canadian triathlete Lionel Sanders has publicly shared his experience with REDs. He suffered from a sacrum fracture — his third bone injury within 14 months — along with training disruptions from injuries, which forced him to withdraw from two Ironman competitions.
Some athletes may assume that recovery is as easy as eating more food. But seeing a medical professional is critical for a safe recovery — suddenly ramping up food intake can lead to complications like dumping syndrome, a condition where food moves to the intestine too quickly after eating. A registered dietician can assess an athlete’s energy expenditure and make dietary recommendations to avoid further medical issues.
“When athletes don’t replenish properly, the body uses up all the glycogen, causing exhaustion, and begins slowing down its metabolism,” said Gist. “After prolonged restriction, it’s vital to see a clinical registered dietician.”
Some activities might carry higher risks of developing REDs. Some famous examples include figure skating and gymnastics, both of which focus on a combination of technique and artistry, which ends up tying lean physiques with athletic success. Well-known athletes, like figure skater Alysa Liu, have detailed how they restricted food and even water while training.
Sports with weight classifications, such as wrestling, subject athletes to weigh-ins that can push them to quickly cut weight to meet a certain limit. Endurance athletes, like marathoners or swimmers, experience a higher risk of underfueling due to their intense workouts. Sometimes, underfueling is unintentional and is not recognized by athletes and their coaches until symptoms like chronic fatigue set in.
Michael Lee, a senior and water polo captain in San Jose, California, felt that the busy environment may have pushed him to accidentally forget to eat enough. “During my junior year games, I’d be so tired due to underfueling, as it was a stressful year and I had less time to eat before and after games,” he said. “It hurt my performance and when I got injured or sore, it was hard for me to recover.”
Athletic culture plays a major role too. Youth sports have become increasingly competitive, which has pushed young athletes — many of whom are still developing and growing — to train harder. Team environments can also reinforce this harmful cycle through body-shaming. Social media only adds fuel to the fire, exposing young impressionable viewers to a flood of fitness and diet content. This includes physique transformations to “what I eat in a day” videos, which can unintentionally promote unhealthy comparison.
“I definitely have seen a lot of stuff online promoting being skinnier and not eating enough,” San Jose-area high school senior and track athlete Xiaoya Gao said. “It’s a social standard that paints a toxic image of what we should be and affects our relationship with food.”
To prevent REDs, experts say it’s important for sports culture to shift the focus from weight to ensuring athletes eat enough food and are aware of changes in their energy levels or mood. Student athletes need extra fuel and hydration and rest to recover in between training sessions.
It’s important to coaches and parents to ensure that young athletes are doing everything possible to protect their long-term health. “I always tell my athletes to make sure they’re eating enough calories, hydrating and getting ample sleep,” Luo said. “In my classes, I go over things like micronutrients, macronutrients, how they’re processed in the body and calorie tracking.”
Experts say athlete health can be supported through expanding nutrition education to inform students about their bodies and needs, and by normalizing nonjudgmental conversations around eating enough food, which can help athletes recognize warning signs before they escalate.
“Talking about it more is important, as people will be less inclined to think they’re just having a bad day and realize they’re maybe not getting enough nutrition,” Lee said. “It would be helpful for coaches to educate athletes on how much they should be eating and nutrition at the start of the season instead of just driving them to work harder.”
