What do Females risk if they don’t fuel enough?

A common concern we hear from women who are dedicated gym goers, runners, triathletes, or team sport athletes is that their period has stopped or it has become irregular. This is more common than you think! Regardless of what you are training for or how fit you think you are, it’s not normal or healthy to not have a period. It is a sign that your body is undergoing significant stress, so please don’t ignore it!!

Have you ever considered the risk of not fuelling your body appropriately? 

Relative Energy Deficiency in Sport (RED-S) is a condition that impacts many active females, yet it is often misunderstood or overlooked. RED-S arises from a critical imbalance known as low energy availability (LEA)(1). LEA occurs when the energy consumed through food is insufficient to cover both the energy expended during exercise and the energy needed for basic bodily functions to maintain optimal health (2). This means that after accounting for the calories burned during exercise, there aren’t enough calories left to support basic bodily functions, leading to potential issues like fatigue, hormonal imbalances, and decreased performance.

When energy intake doesn’t meet the demands of daily functions and physical activities, the body starts to conserve energy in critical areas. This leads to disruptions in multiple systems, including metabolism, the endocrine system, and bone health, and can even affect mental health (3).

Is RED-S intentional or unintentional?

A lot of the time RED-S is unintentional. It can happen when an increase in training load is not matched with an appropriate increase in overall energy intake. Or it can be that you underestimate the amount of energy that is required to support their training volume. Or that you underestimate the amount of energy expended outside of your training, for example, if you have a job that requires you to be on your feet all day you are using more energy than a teammate who works a desk job even though you do the same training session in the evening, your energy demands will be different. (4).

However, sometimes RED-S can occur because of intentional restriction of energy intake through dieting or trying to manipulate your body composition. This can in turn lead to disordered eating behaviours or an eating disorder. Eating disorders are complex conditions and are caused by a combination of social, physical and emotional factors (5). A discussion of these is outside the scope of this article. Therefore, if you think you have an unhealthy relationship with food and your body image, firstly know that you are not alone and secondly, we can support you through 1:1 consultations. 

What do you need to look out for?

The signs and symptoms of RED-S are varied and can affect different systems in the body, making it a complex condition to identify.

Some key symptoms you should look out for are, particularly when your training load increases:

Do I even need to worry about RED-S? How common is it? 

RED-S is more common than you realise, especially in weight-managed sports or when coaches and athletes hold the belief that “lighter means faster,” when in reality, that’s often not the case. Research indicates that a significant number of female athletes, ranging from 6% to as high as 79% depending on the sport, experience some form of menstrual dysfunction, a key indicator of RED-S (6).

Are there any athletes more at risk of developing RED-S?

Athletes in sports that emphasise aesthetics, low body weight, or endurance, such as gymnasts, dancers, figure skaters, and long-distance runners, and those in weight-class sports like rowing, boxing, or weightlifting, are at higher risk (7). Or, girls who feel societal or social media pressure to conform to certain body standards are also at risk. However, RED-S can occur in any active woman, regardless of sport or competition level, and does not require an athlete to appear thin or obviously restrict their intake.

The elephant in the room- how do you speak to your teammates and friends about body composition and weight? How does your coach speak to you?

We often see coaches praising athletes for appearing lean or for losing weight. While these comments might seem harmless, they can significantly impact those who struggle with body image issues or disordered eating habits. Such praise can reinforce the idea that being lean is crucial for worthiness, potentially leading you to under fuel and under-recover, which impairs your performance. If a coach, whose approval you highly value, endorses a particular body type, it may create fear in you to change. You might worry that eating more to enhance performance could alter your body composition and affect your coach’s approval, or how others perceive you.

It’s not only coaches. I see it first-hand myself within female changing rooms or even in a gym environment. We can laugh and joke with each other and typically shame our bodies and it can seem harmless but it can add to the narrative and compound over time. Others might look at you shaming yourself, thinking ‘I wish I had that body’, which can then influence not only your own decisions around food but also those in your company. 

We must hold coaches, teachers, trainers and each other accountable for our language. Casual remarks about body shape or weight can have lasting negative effects, influencing us to restrict our nutrition and suffer both physically and emotionally. 

But why do your periods stop?

One of the most notable signs for female athletes is menstrual dysfunction. The absence of periods, known as hypothalamic amenorrhea (HA or FHA), is often one of the first signs that your body is under stress. The reason your periods stop when someone is suffering from RED-S is that, when the body lacks energy, one of the first things it can do to save energy, without compromising its ability to survive, is to switch off our reproductive system.

We need our cardiovascular system, our nervous system and our immune system to live (9). But our reproductive system is not essential to our next breath. Not all women who have RED-S will lose their periods completely, instead, cycles may become irregular and periods heavier with worse symptoms. If the menstrual cycle is a reflection of our overall health and well-being, it will clearly show signs of disruption in someone experiencing RED-S.

It’s important to understand that while some may see this as a non-issue, particularly if you’re not planning on having children yet, the cessation of menstruation is a clear indicator that your body’s hormonal balance is disrupted, which can have serious long-term consequences.

I am meeting my total energy requirements, why is that not enough?

For females, it’s not as straightforward as calories in/ calories out regarding energy balance and physiological function. It’s not just about your total daily caloric intake; the timing of meals also plays a crucial role in preventing LEA and RED-S. 

Why you shouldn’t go 4-5 hours without eating

In-day energy deficits – periods when your energy intake doesn’t meet the demands of activity levels, can significantly affect you, even if your overall daily calorie consumption seems adequate (10). Therefore, you need to plan your meals carefully to avoid these deficits.

Do you ever train fasted or have no appetite after exercise?

In-day energy deficits contribute to LEA because you might go for extended periods without eating enough, especially around training sessions. For instance, if you have an intense workout in the morning but skip breakfast or have a light snack afterwards, your energy stores may be depleted for several hours. During this time, your body doesn’t have the energy needed to maintain essential physiological processes. This creates a temporary energy deficit that can add up over time, leading to overall LEA, even if total daily calories seem adequate (11).

This can also exacerbate RED-S because regular gaps in fuel intake cause the body to enter periods of energy conservation. When your body is under-fueled, it will always prioritise movement (from exercise) or energy for essential systems like cardiovascular and nervous functions but will deprive other systems, such as reproduction and bone maintenance. 

I’m concerned I have RED-S, how do I get it diagnosed?

Before you make any self-diagnosis, you first need to be reviewed by a medical doctor. Because RED-S can present similarly to other conditions, it is a diagnosis of exclusion, meaning other conditions must be considered and ruled out. This process typically involves a detailed medical history, physical examination, and various diagnostic tests to rule out other potential causes for the symptoms. 

The bigger picture and long-term consequences if left untreated

The long-term consequences of RED-S can be severe and far-reaching, affecting multiple systems in the body:

• Bone Health: Chronic low energy availability can lead to decreased bone density, increasing the risk of fractures and long-term issues like osteoporosis (3).
• Menstrual Function: Persistent menstrual irregularities can have implications for fertility and long-term reproductive health (5).
• Energy Metabolism: Disruptions in metabolism can make it difficult to maintain a healthy weight and energy levels, even after recovery. (12)
• Immune Function: A compromised immune system can lead to frequent illnesses and slower recovery from injuries.
• Cardiovascular Health: Long-term energy deficiency can impact heart health, increasing the risk of cardiovascular conditions (7).
• Mental Health: RED-S is associated with higher rates of anxiety, depression, and other mental health disorders, which can impact both athletic performance and overall quality of life (12).

How is RED-S treated and how long does it take to recover?

Recovery should ideally occur with the support of a doctor and a registered dietitian/ nutritionist. But ultimately when it comes to getting your period back, addressing the root cause is key. The primary treatment for RED-S involves lifestyle changes aimed at restoring energy balance. This includes an increase in your daily calorie intake and/ or reducing the amount/ intensity of exercise. Eating a sufficient amount of calories from quality sources of carbs, protein and fat is a priority. And addressing any psychological factors that may contribute to disordered eating or excessive exercise. Often this will mean restoring any lost weight and gaining additional weight.

Treatment duration can vary depending on the severity of the condition and how long it’s been present. For some, it may take several months to regain normal menstrual function and recover fully, while others might need longer-term support.

Changing the Narrative

Changing the narrative around RED-S is crucial for both prevention and treatment. Addressing RED-S not only safeguards long-term health but also helps athletes perform at their best by keeping the body strong, resilient, and ready to handle the demands of training. It’s essential to move away from normalising the loss of periods in active women or viewing it as a sign of dedication or fitness. Similarly, directing athletes to contraceptive pills to “regulate” periods without addressing the underlying issue only masks the problem.

We must encourage a culture where food is seen as fuel, not the enemy. Coaches, trainers, and athletes alike should be educated about the signs of RED-S and the importance of proper nutrition. Comments about body size or weight, whether from coaches, peers, or society, can have long-lasting effects and contribute to the development of RED-S.

By recognising the signs early and taking proactive steps to restore energy balance, we can help prevent the long-term consequences of this condition. Prioritising proper fueling, recovery, and a balanced approach to training ultimately leads to sustained performance and progress. Shifting the focus from restrictive habits to smart nutrition strategies ensures that athletes compete from a position of strength and health, setting themselves up for long-term success in their sport.

References: 

1. Mountjoy, M., Sundgot-Borgen, J., Burke, L. M., & Meyer, N. L. (2014). The IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. British Journal of Sports Medicine, 52(11), 699-715. https://doi.org/10.1136/bjsports-2018-099193
2. Heikura, I. A., Uusitalo, A. L., & Nupponen, H. (2020). Energy availability in female athletes: A review of research and practical recommendations. European Journal of Sport Science, 20(5), 621-631. https://doi.org/10.1080/17461391.2019.1700317
3. Tenforde, A. S., Fredericson, M., & M., S. (2013). Bone health in athletes: A review of the literature. Current Sports Medicine Reports, 12(6), 355-362. https://doi.org/10.1249/JSR.0b013e3182a1e5b2
4. Loucks, A. B., & Thuma, J. R. (2011). Low energy availability and the menstrual cycle: Effects on bone health and metabolic function. Journal of Athletic Training, 46(2), 174-184. https://doi.org/10.4085/1062-6050-46.2.174
5. Sundgot-Borgen, J., & Torstveit, M. K. (2010). Prevalence of disordered eating and eating disorders in female elite athletes. Medicine & Science in Sports & Exercise, 42(5), 1086-1095. https://doi.org/10.1249/MSS.0b013e3181cb07d2
6. Crispim, S. P., Lima, L. A., Almeida, C. J., & Moreira, R. M. (2021). The prevalence of menstrual dysfunction in female athletes: A systematic review and meta-analysis. Sports Medicine, 51(4), 721-731. https://doi.org/10.1007/s40279-020-01321-6
7. Ackermann, B., & Ackermann, M. (2017). The impact of low energy availability in athletes. International Journal of Sport Nutrition and Exercise Metabolism, 27(3), 226-233. https://doi.org/10.1123/ijsnem.2016-0235
8. Kirk, B., L. V. H., Smith, J., & Williams, E. M. (2017). Physical growth and development in athletes: Impact of training on bone health and hormonal balance. Journal of Sports Sciences, 35(16), 1592-1600. https://doi.org/10.1080/02640414.2016.1212734
9. Loucks, A. B. (2006). Energy balance and menstrual function. Nutrition Reviews, 64(5), S12-S19. https://doi.org/10.1111/j.1753-4887.2006.tb00245.x
10. Burke, L. M., Hawley, J. A., Wong, S. H., & Jeukendrup, A. E. (2011). Carbohydrates for training and competition. Journal of Sports Sciences, 29(sup1), S17-S27. https://doi.org/10.1080/02640414.2011.580828
11. Marty, L. M., Zinner, C., & E. C., T. (2021). Daily energy deficits and their impact on low energy availability in athletes. International Journal of Sport Nutrition and Exercise Metabolism, 31(4), 342-349. https://doi.org/10.1123/ijsnem.2020-0203
12. Melin, A. K., Heikura, I. A., & L., T. A. (2014). Diagnosing and managing RED-S in athletes. Clinical Journal of Sport Medicine, 24(4), 310-319. https://doi.org/10.1097/JSM.0000000000000057