Sports Nutritionist: Relative Energy Deficiency In Sports

Reading time: 12 min read
Many athletes are still pushed into deficient nutrition based on false preconceptions. It is time we change that.
Sports Nutritionist: Relative Energy Deficiency In Sports

Tina Goršek Šparovec is a young researcher in the field of gynecology at the Medical University in Graz. She finished her Master's Degree in nutrition and biomedicine at a world-renowned Technical University in Munich. At the Human Performance Center, she combines her knowledge in gynecology and endocrinology. She does research activity and regularly educates coaches who need more knowledge on female physiology. She directly counsels female athletes and helps them to better understand their body and its capabilities. Her mission is based on the desire to make coaches understand and take into consideration the needs of female athletes and consequently create optimal training sessions, supported by an adequate nutrition strategy. She believes this is the only way to achieve optimal results.

Hello, Tina. Can you briefly explain what RED-S is?

RED-S or relative energy deficiency in sport is a condition in which we are not able to consume enough energy to support all body functions and our sport activity, which keeps us in a constant energy deficit. 

When we remain in an energy deficit for a longer period of time, our body's response is to limit certain body functions. This is based on hierarchy. First, the body shuts down or adapts the body functions not essential for survival. This leads to the classic RED-S symptoms.

How long has this problem been known?

It has been a known female athlete problem for some time. It was called the female athlete triad. It was noticed that young female athletes in periods when they train a lot or have a very low body mass get their first menstruation very late or lose it.

This has already been described. It is known that female athletes have a higher occurrence of stress fractures, anemia, and similar problems.

In the last few years, we noticed that there are more and more symptoms related to RED-S: it's not just bones, menstrual function, and undernutrition, it also affects our immune system, digestion, and mental health.

Relative energy deficiency in sport (RED-S)RED-S has numerous negative effects on the health of young female athletes.

Can men also have RED-S?

We used to think only female athletes can develop RED-S because the menstruation was such an obvious sign.

But lately we see that it also occurs in men. They experience a drop of testosterone and all the related consequences. Men can also experience other RED-S symptoms.

How do we discover RED-S?

Men have a harder time noticing it than women, but we can definitely discover it with a blood test and a questionnaire, after we rule out all other options.

Why is it harder for men to notice it?

The menstruation is such an obvious sign.

Men can notice other symptoms. Loss of their morning erection, sleeping disorders, or lower libido, but when an athlete is really active, all these things are constantly present to a certain degree. They don't perceive it as a sign.

Izguba libida in jutranje erekcije zaradi RED-SLow of libido and loss of morning erection can be a signal for men they are developing RED-S.

The doctors are also unable to recognize RED-S?

Yes, they absolutely have a hard time recognizing it. Not everyone comes to the conclusion that a loss of morning erection could be a consequence of too much sport.

And the doctors find a lack of menstruation also to be quite normal?

Gynecologists are increasingly more aware. Recently, I was debating with a gynecologist, with whom I will work together in the future, who said that they are noticing girls losing their menstruation and also treat them. But still there are some who claim the menstruation is only cosmetics.

How do they treat them?

One thing is to give them recommendations to eat more and train less, but the girls usually have a hard time sticking to this, so after some time they are offered a hormone replacement therapy, but this is not a long-term solution.

The gynecologist should find a link and make contact or send them to a dietician or nutritionist to help them with nutrition. They should also be sent to a psychologist to help them change their lifestyle.

Zdrav življenjski slog in RED-SFor young female athletes, a healthy lifestyle is essential.

We have the athlete, coach, doctor, nutritionist ... Who in this chain should recognize and prevent RED-S?

It can be recognized by the doctor, coach, gynecologist, but the nutritionist should definitely notice an athlete is not eating enough.

But everyone is avoiding RED-S treatment. The doctor sends you to an endocrinologist, the gynecologist sends you to someone else or prescribes pills. But it never happens that the gynecologist sends you to the nutritionist, who could tell you what you should eat.

The gynecologist considers the problem to be hormone related and can be fixed with pills. This may be true, but let me stress again that this is not a wholesome solution. The reason for RED-S remains.

The nutritionist is the one who can do the most here, as we are dealing with a chronic energy deficit, incorrect nutrition, and incorrect use of food during training.

Do you think all segments should be connected?

Absolutely. This is why I work with a gynecologist.

He also has several cases of women without menstruation. My aim is to be able to send my protégés to someone I can trust to have adequate knowledge in gynecology and can give proper advice, someone who doesn't just prescribe pills but recommends a change in nutrition and lifestyle.

Do you think it's a defense mechanism of the experts that they don't dare to admit something is out of their expertise and direct their patients to someone else, preferring to seek a solution within their own field, like prescribing pills, when they should find the source of the problem, not just treat symptoms?

I think they are not connecting enough. It's not a gynecologist's domain to follow nutritional factors and how someone eats or how physically active they are.

The goal is to work together.

Once there is a connection between the gynecologist, nutritionist, psychologist, perhaps a kinesiologist, this is a team that could really help girls in a wholesome way.

Tablete, zdravila in RED-SThe pills are not the solution. Wholesome treatment is needed.

Do you think this can be done?

Yes, I think so.

I am working on something like that myself at the kinesiology center Bio-Fit, where they deal with eating disorders. They have a kinesiologist, dietician, psychiatrist, and gynecologist.

People with eating and nutritional disorders need wholesome treatment to get results and restore their health.

Can a nutritionist take responsibility for the girls' health?

It is difficult to put the burden of responsibility on anyone.

Also because we often work with girls that have other problems besides nutrition.

If her psychological health is at stake, this is not the domain of a nutritionist or gynecologist. We often resolve issues and fears related to food that originate from somewhere else. Is this the psychiatrist's responsibility?

So the girls are on their own?

It is difficult. These girls are really on their own. They struggle every day to find the motivation to eat more and choose the correct foods.

You can't hold their hand every day and tell them what to eat. A girl must be prepared to do it herself. There is a big difference between me as a nutritionist and my colleague who works with girls with serious eating disorders. She needs to convince her protégés to eat.

Relative Energy Deficiency in SportIt is difficult to say who's responsible for the health of the girls with severe eating disorders.

Is this still RED-S or is it something worse?

It's the next level. It's an eating disorder.

RED-S is not an eating disorder?

RED-S is a consequence of an eating disorder. Eating disorders are possible reasons for an energy deficit.

And the other reasons are?

There are many.

Intentional reasons are when a person opts to lose weight, fasts, trains on an empty stomach.

Unintentional reasons are when a person has a gastrointestinal disorder and suffers from poor nutrient absorption.

More training sessions per day, loss of appetite. There are many reasons. It is not given eating disorders are behind it.

And, of course, psychological reasons?

Many people in RED-S are perfectionists who want to have things under control.

When you start to constantly control food and this gives you a sense of safety or you start considering certain foods dangerous, you can develop anxiety about nutrition.

Psihološke težave in RED-SRED-S is often a consequence of psychological issues.

Can a female athlete who has a regular body mass still develop RED-S? That she simply doesn't have enough energy for training?


Definitely, in spite of a low energy intake, our body mass may stay unchanged.

The metabolism adapts, which I already mentioned. By shutting down its functions, the body spends less energy. So we need to eat even less if we want to lose body mass.

It is also true that we may start to retain water, so the scale might not necessarily show a decrease in weight. The number on the scale is not everything.

What about macronutrients? For example, you don't eat carbohydrates before training, and then you eat fatty foods afterwards.

The ratio of macronutrients is important. The time of intake of an individual macronutrient is also important.

For example, if we don't eat carbohydrates after training but nuts, the body doesn't get the signal that there is enough energy, and the insulin doesn't rise. This causes the body to think it is still in an undernourished state.

Delaying the intake of carbohydrates after an exhausting (endurance) training session delays the recovery. And the body remains under the influence of stress hormones for a longer period.

Zdrav obrok po napornem treningu in RED-SIt is important to consume enough carbohydrates after exercise.

If this lasts for a longer period, it can definitely lead to RED-S.

So, you can eat a lot and still develop RED-S?

Yes, or if you don't eat regularly.

A study compared the time of calorie deficit among girls with hypothalamic amenorrhea (lack of menstruation) and healthy girls. The girls without menstruation are in a deficit longer throughout the day.

A female athlete can eat three main meals, but with training the level of energy drops really low. This is why athletes perhaps should have snacks before and after training, so they are in a calorie deficit for as little time as possible, and at the same time this would allow them to replenish glycogen stores with carbohydrates, especially in endurance sports.

So you would advise against diets such as intermittent fasting?

Yes, for (endurance) athletes definitely.

The body spends a lot of time in calorie deficit, and the energy debt of physical activity increases. RED-S is behind the corner.

We must also take into consideration that glycogen needs 16 to 36 hours to replenish. Intermittent fasting does not allow you to replenish your glycogen stores.

Pravilna prehrana zdrave športnice in RED-SA healthy female athlete makes sure to consume enough macronutrients her body needs.

Ok, you have RED-S. What now?

The first thing to do is visit a doctor or gynecologist to check the hormone condition. Then seek counselling of someone working with RED-S, a nutritionist, who is familiar with the causes and the consequences.

At the same time, visit a psychologist, especially if there are psychological problems.

And then the journey begins. You need to eat more. You need to skip some training sessions. You need to be conscious about how you feel during exercise, as often it turns out that because of RED-S you cannot perform that well anymore. A battle goes on in your head. You think you don't feel good during training sessions because you didn't train long or hard enough.

A break is recommended. Then you slowly start to come back. Sometimes this takes a long time, six months or a year to get back and start to train normally. Slowly, you get to the level at which you were or even improve.

Once we add more food to an athlete's diet, they may begin to feel better, train better, and progress faster.

RED-S can also have life-changing consequences?

Yes, it can.

If we have RED-S for a longer period of time, our bone density is reduced and we might even have developed osteoporosis. It can be life-changing to have a bone mineral density of an 80-year old at 25.

Zdravje in gostota kosti ter RED-SRED-S can have lasting consequences for the health of your bones.

And this is difficult to heal?

Yes, you have to put a lot of work into it. And it will never be like it was before.

How soon must we discover RED-S so that it's not too late?

As soon as possible.

But it's still considered perfectly normal to be without menstruation for some time.

It shouldn't be considered normal.

Up to three months it's not even considered you have amenorrhea.

Some girls don't even lose their menstruation, and they can still have RED-S or be overtrained. 

Girls come to you with RED-S. How do you help them?

First it depends whether she's an athlete or not.

On one hand, we have girls who decide to go to the gym and mind what they eat, and on the other we have serious athletes who train regularly and have competitive ambitions.

For the latter, it's more difficult to make them quit training and realize they won't be able to go on like this and that they need a break.

In this case, I get in touch with their coach and help them with counseling. Girls like this need to adapt their training sessions and take care of proper nutrition, establish a healthy relationship with food, or simply learn how to eat around training sessions because many do not possess that knowledge.

Pravilna prehrana športnikov in RED-SSuccessful athletes pay a lot of attention to proper nutrition.

How do the coaches respond when you tell them one of their girls needs to eat more?

It depends.

They definitely support the idea that the girl should get better, but sometimes they feel attacked. They blame the girls, say it's their decision to push themselves too hard, and this is often true. But the girls and the parents trust the coach to take care of them and be mindful of any changes.

Girls often do extra training sessions on the side because they think they will improve or lose body mass.

What about the psychological aspect of treatment?

I try to talk with them.

Their mind often works against them, they start going in circles.

They go to the store and can't decide if they want to take a yoghurt with strawberry or banana because there is a 5-calorie difference. Or in a restaurant, they don't know whether to choose a salad, which is supposed to be healthy and is promoted by Instagram, or pasta, recommended by Tina before a hard training sessions.

Such decisions make them lose lots of time and drain lots of energy, and often they are not able to decide correctly.

Prehranske težave in RED-SPsychological issues with food can drive someone to desperation. 

How do you solve this by talking?

You have to motivate them to make better decisions for themselves.

That's not always possible.

Sometimes it's good to send them to a psychologist. It can be childhood traumas that caused this need for control that affects their nutrition. As a nutritionist, this is something I cannot solve.

What is the final sign that we need to seek help?

I have a few criteria.

The first one is sleep. How do we sleep? Do we wake up at night? Do we have to urinate during the night? Do we wake up early or cannot fall asleep in the evening?

Then there's the training. How do we perform? Do we constantly feel tired? Are we not in the mood for training? Are we lacking motivation?

Padec motivacije za trening in RED-SA drop in motivation for training can be a warning sign that we have RED-S.

An excessive obsession with food or avoiding certain nutrients can also be cause for alarm.

This might be difficult today when everyone is selling a certain diet and with the spread of the mentality that to achieve results, we need to suffer.

Yes, yes, yes.

This should be addressed. What happens in your head if you have to skip one training session. To some people, this is more difficult than getting a driver's license.

Are you capable of skipping a training session if you decided to go out with friends or are you afraid that you will deteriorate as an athlete?

This tells us a lot about your relationship with sport.

Odnos do športa in RED-SAn athlete must also know how to relax.

Can top level athletes afford that, though?

That's a difficult question. It's what makes them elite.

On the other hand, top-level sport is a safeguard. Off season, you can see what's really going on. Will you enjoy yourself for three weeks and do other things that make you happy or will you feel anxious because you can't train?

This might actually be a bigger issue with amateur athletes than professional ones.


Professional athletes are maybe aware that this is their job and that after training they are free, but for amateurs this line is not so clear.

And yet, many professional athletes have RED-S.

In gymnastics, track and field, dance, in those sports the prevalence is much higher because the need for the athletes to have a low body mass is much higher. In those sports, RED-S is more present.

What's the percentage of endurance athletes who have problems or potential problems with RED-S?

Given that the absence of menstruation with runners is more than 50%, I'd say that many.

How many of them are at least somewhat aware they have issues?

Much less than that. This is why we talk about it so much.

RED-S med vrhunskimi športnicamiRED-S is also spread among top-level female athletes.

What can we do to make things better?

First of all, educate the people involved.

If a girl tells you she lost her menstruation, this should be cause for alarm that her nutrition, training, or recovery are not ok.

We need to educate athletes on sports nutrition, on gynecologic problems. We need to speak to the coaches so that they are aware why women have a menstrual cycle, why that is good. They need to have that knowledge and be able to talk about it with their female athletes.

Recently, I lectured to young biathletes about nutrition. The coach was present, and we were able to normally discuss menstruation. He was interested in the subject. It was a good experience for everyone.

We need to educate them on eating disorders. How to work with a girl like that, how to approach the situation.

This is what I am working on.


Want to learn more about nutrition? Check out these knowledge-packed interviews!

Malnutrition Amon Young Female Athletes - Interview With Tina Goršek Šparovec 

Muscle Recovery - Interview With Dr. Tim Podlogar

The Optimal Fuel For Cyclists - Interview With Dr. Tim Podlogar


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