RED-S stands for Relative Energy Deficiency in Sport. It happens when athletes eat insufficient food relative to the number of calories they burn. Rowers who enjoy the See Food Diet —they see food and eat it— are less likely to experience RED-S than those who eat restrictively because they are fearful of gaining weight. Rowers who eat only “healthy” foods can also slide into RED-S when they consume too few calories to support optimal physiological function.

Athletes most at risk for RED-S tend to be in sports that:

• emphasize appearance (figure skating, dancing)
• have weight categories (wrestling, rowing) 
• require endurance (running, cycling)

But any athlete can suffer from RED-S—even those who have not lost weight. Take note: Under-eating is not always accompanied by weight loss. When the body perceives a “famine” (too little fuel), it does an amazing job of preserving itself from wasting away. 

I get concerned about RED-S when I hear rowers say things like: 

“My friends tell me I eat like a bird…”

“I’m not losing weight, despite all my exercise. Am I eating too much—or too little?”

“I stopped getting my period last year. My doctor said that’s normal for female athletes.”

As mentioned above, RED-S is common in weight-conscious and weight-class athletes. Case in point: A survey of male and female competitive lightweight rowers, age 18 and younger, revealed that many of the rowers had RED-S. They ate an inadequate amount of food relative to what their bodies needed. They prioritized weight over health to qualify to row. As a result, the under-eaters experienced excessive fatigue, muscle loss, poor recovery between training sessions, stress fractures, and reoccurring injuries. 

Interviews with the rowers indicated they knew very little about RED-S. Most of the rowers—as well as their health-care providers—thought RED-S affected only women who had stopped having regular menstrual periods. Wrong. RED-S applies to both male and female athletes.

Because lack of RED-S education can contribute to long-term health issues for males and females alike, please share this article with your partners, teammates, and others whom you may have noticed “eating like a bird.” 

A telltale sign of RED-S in males is loss of libido and sex drive and in females irregular or no menstrual period. Other health issues related to RED-S include weight loss (but not always), reduced bone health that shows up as stress fractures today and osteoporosis in the future, chronic fatigue owing to poorly fueled muscles, nagging injuries, moodiness, and depression. Performance issues include the inability to gain or build muscle or strength, reduced agility and coordination, poor recovery from hard workouts, impaired judgment, loss of mental sharpness, and reduced ability to focus. A rower’s plan to lose weight to enhance performance commonly backfires in the long term, if not the short term.

As mentioned above, RED-S appears in not only rowers who consciously restrict their food intake but also those who consume inadequate fuel to support their body’s energy needs unknowingly. This can happen with rowers who juggle school, work, family, friends, and training demands—and have “no time” to eat. RED-S can happen also to rowers whose “healthy diet” includes a lot of high-fiber foods, such as beans, nuts, and whole grains that can curb one’s appetite. Or maybe the rowers believe they are eating enough because they eat large portions, but the foods are what I call “fluff”—rice cakes, popcorn, lettuce, etc. 

While restricting food and prioritizing weight over health has become normalized among rowers, you need to know that under-eating is not harmless. Living with an energy deficit affects every system in the body, including the gastrointestinal system (reduced GI motility, constipation), cardiovascular system (dangerously low heart rate, unusual fatigue), slowed metabolism (energy conservation, cold hands, cold feet). A rower should never try to maintain a “racing weight” all year round. 

Lack of knowledge about RED-S can lead to under-diagnosis, poor management, and negative health outcomes. For example, some health-care providers tell female rowers still that amenorrhea is normal in women who train hard. The recommendation to “just take a birth control pill to get your period” is outdated and does not resolve the underlying problem—an inadequate amount of fuel to support the normal functioning of the whole body.

Do you have RED-S? 

Here are a few questions that could help determine whether you are under-eating. Do you:

• Constantly think about your food, weight, or body image? 
• Severely limit your food intake?
• Experience guilt or shame around eating “unhealthy foods”? 
• Count calories or fat grams whenever you eat or drink? 
• Feel fat even though others tell you that you are thin? 

What’s the solution? 

If you are training hard and eating very little, you could be experiencing RED-S. While the obvious answer is to eat more and exercise less, doing so can be difficult. Fear of weight gain is a huge barrier. As I hear repeatedly from my doubting clients, “What makes you think I could eat more, exercise less, and not get fat? That just doesn’t make sense.” 

Well, it does make sense, because the body does an amazing job of conserving energy, as indicated by cold hands and feet, low heart rate, and loss of menses and libido. When you eat more, your metabolism perks up and you burn off the added calories (as opposed to storing them as excess flab). You’ll then be able to train better, recover better, and row better. If you are under-eating, start by adding 100 to 300 calories to breakfast, then lunch, and then afternoon snack.

 Is it time to revolutionize the culture of sport so that rowers and other athletes can focus more on performance and health and less on weight? To initiate this change, you might want to train at a weight that fits your genetic physique and allows you to prioritize health over weight. Excelling as a strong and powerful rower could lead to a more satisfying rowing career than starving yourself to be an injury-prone lightweight rower who spends too much time on the sidelines. 

Bottom line: If you think you have RED-S, talk with a trusted sports dietitian. Poorly managed RED-S can lead to malnutrition, disordered eating, osteoporosis, and a disappointing future for your athletic aspirations.

Nancy Clark M.S., R.D., C.S.S.D., counsels both fitness exercisers and competitive athletes in the Boston area (Newton; 617-795-1875). Her best-selling Sports Nutrition Guidebook is a popular resource, as is her online workshop. Visit NancyClarkRD.com for more information.