Relative Energy Deficiency in Sport (RED-S)

Relative energy deficiency in sport (RED-S) is a health condition that can happen when you burn more calories from exercising than you take in. It can hurt your body if it goes on for a long time.

Calories in the food you eat every day are the energy your body needs to perform — not just for your sports and workouts, but to stay alive. You need energy for your organs to work properly.

RED-S used to be called the female athlete triad. But healthcare providers have changed its name to recognize that it can affect anyone, even if it’s more common in female athletes.

Symptoms of RED-S

Burning more calories than you take in every once in a while isn’t harmful. But RED-S sets in when it happens too often. Your body is using more energy than it’s getting from food. The sustained calorie deficit will start to affect your health. This can lead to lots of symptoms, including:

• Fatigue
• A noticeable drop in your athletic performance and stamina
• Taking longer to recover between workouts or training sessions
• Unintended weight loss
• Trouble sleeping
• Digestive issues, like gas, bloating, constipation or diarrhea
• Dizziness
• Dehydration
• Hair loss
• Irregular or missing periods
• Trouble sleeping
• Increased anxiety or depression
• Stress fractures that happen often or in the same bones more than once

Relative energy deficiency in sport can also cause issues that aren’t as easy notice, including:

• A slower heart rate
• Bone density loss
• An increased injury risk
• Taking longer to heal after injuries
• Getting sick more often, and taking longer to get better when you're sick
• Delayed puberty or stunted growth in kids and teens

RED-S causes

Burning more calories than you consume too often can lead to RED-S. It can happen to anyone, but it’s most common in athletes and people who are very active.

Your body turns the food you eat into energy that fuels your body. It needs energy to keep your heart pumping, lungs breathing and brain functioning. That’s why you burn calories constantly, even when you’re sleeping or sitting still.

Working out, playing sports or doing any physical activity increases how many calories you use. RED-S happens when you aren’t getting enough calories to make up for the ones you've burned. That’s what its name means:

• Relative: Everyone needs a different number of calories each day. How many you need depends on lots of factors, like your age, body size, activity level, health conditions and natural metabolism.
• Energy: Calories you eat become the energy your body uses.
• Deficiency: A deficiency is a lack. RED-S happens when you’re consistently short on calories and energy in your body.
• In Sport: RED-S almost always affects athletes because they do intense exercise more often than most people.

Nutrition is a complex science that affects everyone differently. But in the simplest terms, you need to take in calories from food and drinks to balance out how many you’re burning while you exercise. If you do a lot of intense workouts or train all the time, you might be using more calories than you realize.

Some people intentionally eat fewer calories than they need. But even if you’re trying to lose weight, your body still needs enough energy to function. You shouldn’t skip meals or withhold food from yourself to lose weight. A healthcare provider or dietitian can help you set a healthy calorie target.

Having an eating disorder can also lead to RED-S. Having an eating disorder isn’t a sign of weakness or that you don’t have enough willpower. It’s a health condition with complex causes. Talk to a healthcare provider or someone else you trust if it feels like eating, exercising or thinking about food is causing you extra stress or hurting you.

How doctors diagnose this condition

A healthcare provider will diagnose RED-S with a physical exam and by asking about your health and nutrition. Tell your provider if you’ve noticed any symptoms and when they started. Explain how you train, which sports you play and how active you are in general.

Your provider will examine your body if you have pain or any injuries. They might ask about what kinds of food you eat most often and how much you’re eating. They’re not trying to trick you or make you feel bad. There’s no right or wrong answer. They just want to understand why you might not be getting enough calories. Tell them if you’re having any negative thoughts about food or your body.

Your provider might suggest some tests to check for injuries or signs of other issues in your body. You might need:

• X-rays
• Blood tests
• A bone density test

How is it treated?

Balancing how many calories you take in compared to how many you burn is the most important part of managing RED-S.

There’s no one-size-fits-all solution that works for everyone. Your healthcare provider may suggest that you work with a registered dietitian. They’ll help you come up with an eating plan that meets your needs. Your dietitian will help you maximize your performance while getting the right nutrition.

You might need to take a break from exercise, training or playing sports to help your body leave the unsafe calorie deficit. If you feel like it’s impossible for you to stop exercising, you might want to meet with a mental health specialist.

When should I see my healthcare provider?

It can be tricky to diagnose RED-S. This condition can cause lots of symptoms that might not seem related. Noticing that something feels off is usually the first sign. You know your body better than anyone. See a healthcare provider if you feel like your athletic performance is dipping or if you have any symptoms — especially if you feel like you’re having a tough time managing what you eat.

What can I expect if I have RED-S?

You should be able to resume training or working out once you’re getting a safe number of calories. Even if you need to take a break to rest while your body adjusts, you should be able to get back to your sport after a while. Your healthcare provider will let you know when it’s safe for you to resume playing or training again.

RED-S can be a serious condition. But it’s manageable. Athletes and active people sometimes feel like they’re failing by asking for help. That’s not the case. RED-S is a health condition, not a sign that you’re cutting corners on your training. Getting the right amount of nutrition will help you feel better. It'll also make sure your body is able to keep up with you. Your performance and stamina should recover over time.