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  • Writer's pictureMicaela Zettel, PT, MScPT, MCISc AHCP SEM, BScHK(hons),

Energy Crisis for the Female Athlete: RED-S & the Female Athlete Triad.

RED-S stands for Relative Energy Deficiency in Sport, and I’m guessing that a lot of you probably haven’t heard of it. How about the Female Athlete Triad? Maybe? Probably not?

These are both critical considerations when working with female athletes, and after reading this, hopefully you will understand why.

Both of these terms describe energy issues and they can impact the health and sport performance of female athletes of all ages.

In my practice I often work with female athletes dealing with recurring pain and sport performance challenges, and with a few simple questions combined with an in depth understanding of the female physiology, it often becomes clear that they are experiencing an energy crisis.

These conditions are often undetected due to lack of screening by health care providers (Foley Davellar, 2020 ). When this happens, athletes have typically been getting incorrect information and treatment is not effective, or only effective in the short term. It is a missed opportunity for early and appropriate intervention. An athlete battling an energy crisis is going to have a long uphill battle trying to recover and reach their performance goals.

So what is an energy crisis? Both the RED-S and the Female Athlete Triad are used to describe when an athlete is expending more energy than they are taking in.

Females are at risk of this if they exercise intensely and do not consume enough energy (calories from food) to maintain necessary body functions. This leads to a deficit and the body does not have enough energy for normal bodily functions such as hormone and bone health. Without the necessary energy, injuries and serious health issues occur.

To achieve your sport performance goals, you need to first be healthy. For females, this is especially important.

The Female Athlete Triad is used to describe a combination of three conditions: amenorrhea (the menstrual cycle has stopped), osteoporosis (weakening of the bones), and disordered eating (Foley Davellar, 2020 ). As you can guess from the title, this applies to females.

RED-S is a more comprehensive term used to describe an energy deficit problem and it also applies to males. “The syndrome of RED-S refers to impaired physiological function caused by relative energy deficiency, and it includes but is not limited to impairments of metabolic rate, menstrual function, bone health, immunity, protein synthesis, and cardiovascular health(Mountjoy, 2014). This is a complex syndrome with many possible contributing factors. It is also important to note that psychological factors can also be a cause and result of RED-S (Mountjoy, 2014).

As a note, RED-S is becoming more commonly used as it covers both males and females however, the Female Athlete Triad is still referenced in literature and important to cover here.

The figure below shows the potential health consequences associated with the Female Athlete Triad & RED-S (Mountjoy, 2014).

There are also specific effects that happen to sport performance and these are highlighted below in figure 2 (Mountjoy, 2014).

A few things to highlight here. Decreased muscle strength, decreased endurance, and decreased training response can all occur because there is not enough energy to fuel the muscular system, cardiovascular system or to support recovery (recovery is essential for training to be effective). Therefore, the athlete continues to train but there is not enough energy to sustain the muscle strength or endurance required for the sport, this can lead to an increased risk of injury.

An athlete in an energy crisis dealing with an injury does not have enough energy to support healing, let alone training, and recovering from the injury can take a long time. Available energy is critical and dictates how well an athlete can perform, improve, and sustain themselves.

Who is at risk?

Often, when health care providers think of RED-S or the triad, there is a stereotypical picture of an aesthetic athlete that has an eating disorder and/or consciously overexercises. This is definitely a common scenario but it is not the only one. Stereotypes or ‘typicals’ do not serve us well in health care and sport performance.

Research has documented some higher risk categories including sports that are judged and require a certain “ideal” physique (such as gymnastics, figure skating, and dance), endurance sports (where increased weight is perceived as having a negative effect on performance, such as distance running) and weight class sports (ie: wrestling)(Mountjoy, 2014).

In reality, any athlete at any age can run into trouble with an energy crisis.

Female athletes tend to be at higher risk because of physique demands for certain sports, body image challenges that are portrayed in social media and sports media, the increased energy demand of hormone metabolism and the menstrual cycle, and the early adoption of dieting/diet culture. It can also happen unintentionally where the athlete hasn’t learned to adapt proper fueling to new energy demands. Ultimately, there are many variables at play.

The key is to recognize the symptoms and then screen for an energy deficit.

Because changes in the body's energy demands are so important, it is key to note that youth female athletes have high metabolic demands, even without sport participation, as they are going through a time of rapid physical growth and physiological changes. Low energy intake can occur because of an eating disorder, or even unintentionally. Combine this with being active, and there are significant demands on the body’s energy availability. In any case, a team approach (guardians, health care professionals, coaches, etc.) is needed and an individualized plan is crucial for an athlete. Although I am focusing on sport performance, it is imperative that early intervention occurs to prevent and reverse the health consequences that RED-S can have on an athlete.

The goal is and always should be, a healthy, lifelong athlete.

So what can you do?

If you or your female athlete is experiencing any of the symptoms listed below, please talk to your primary health care provider about RED-S and start asking questions.

I have also attached a link to a self administered questionnaire for female athletes that can be completed as a preliminary screen to see if there is a risk of RED-S (the entire article is attached because you need all the info!).

Possible warning signs & symptoms:

  • Recurring injuries/chronic injuries that just seem to come out of nowhere (ie: you didn’t fall or get hit by someone/something, for example: overuse injuries)

  • Low energy/fatigue (feels hard to get through the day without feeling tired/sleepy)

  • Poor sleep (sleeping less than 8-9 hours a night, or you sleep for 9 hours but don’t feel rested)

  • High stress/anxiety (for ex: you get stressed or anxious for school tests)

  • Low iron (need a blood test to determine this) → heavy periods = increased risk of low iron (anemia)

  • No longer get your period (and are not pregnant), and are 16 years and older

  • Digestive issues (IBS, stomach aches, loose stool/constipation, gas/bloating, etc).

  • Frequently getting sick

  • Dehydration

  • Non-traumatic stress fractures (for example: a stress fracture from running versus you jumped and landed funny and fractured a bone).

  • You restrict calories (any type of diet that restricts how many calories you eat, you don’t eat carbs, you eat low fat, you skip meals, etc). (PSA: female athletes need fat and carbs!!!).

  • Regular muscle cramps, muscle weakness

  • Don’t tolerate the cold well

  • Dental and gum problems

  • Exercise excessively

  • Using laxatives or diet pills

If you or your female athlete have any or a combination of these symptoms, it does not mean that you have RED-S but it does mean that you should talk to your family physician or primary health care provider about your health and whether more screening/investigating needs to be done. The symptoms listed are to help you think about your overall health and what other factors might be involved in your pain problem and your sport performance, and to provide you with the tools to help you advocate for your health.

Screening tool & link to article:

As always, I’m here to help. If you have questions, reach out to me via email or social media and check out my YouTube channel for more information.



Female Athlete Issues for the Team Physician: A Consensus Statement-2017 Update. Med Sci Sports Exerc. 2018 May;50(5):1113-1122. doi: 10.1249/MSS.0000000000001603. PMID: 29652732.

Foley Davelaar, CM; Ostrom, M; Schulz, J, et al. (2020). Validation of an Age-Appropriate Screening Tool for Female Athlete Triad and Relative Energy Deficiency in Sport in Youth Athletes. Cureus.

Mountjoy M, Sundgot-Borgen J, Burke l, et al. (2014). IOC Consensus Statement. Beyond the triad – RED-S in Sport. Br J Sports med, 48: 491-7.

Disclaimer: All information provided by can at no time substitute medical advice and individual assessment by a qualified medical professional. recommends seeking professional advice before commencing any type of self-treatment, as the information provided is not intended to be relied on for medical diagnosis and treatment.

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