If you are one of the 300 runners who has helped me fill in a survey in early 2024, I want to thank you sincerely for providing your precious time and personal information. Also a big thank you to all coaches, race directors, running group organisers who have helped me spread the word to fellow runners. Your input was crucial for this project in raising awareness of Low Energy Availability, and for completing my degree in BSc Food and Nutrition.
How I Started This Research Project
As a runner and health coach, I’ve been thinking about the topic of low energy availability (LEA) for several years. I was curious to know how many of us were affected by LEA or if anyone was aware of the consequences on their health. Since I had to do a research project for my degree, it was the perfect opportunity to ask these questions about LEA. Honestly, I do not wish that upon anyone, and I do hope this research project and this article can help raise awareness and maybe some preventive action amongst runners in the community.
Disclaimers
Before I carry on, here are some clarifications:
My background is in health coaching and studying Food and Nutrition, this blog is intended for education and health promotion, rather than medical advice.
The LEA symptoms discussed below are only warning signs, which are not sufficient to identify whether someone is at risk of LEA. Likewise, screening tools used in my research are for identifying potential risks in athletes and not meant for diagnosis either.
Diagnosis for the athlete triad is a complicated process requiring the clinical expertise of a multi-disciplinary team. Should you find yourself experiencing LEA symptoms, please consult a qualified medical professional.
What Is Low Energy Availability (LEA)?
LEA occurs when an individual’s energy intake is insufficient to cover (i) the energy of exercise and (ii) energy to maintain basic physiological functions.
Start digging into a few journals, you will see scientists use a convoluted definition for LEA. The more official definition refers to the “energy availability“ after deducting “the energy expended for exercises” from “energy intake”.
Energy Availability = Energy Intake (EI) – Exercise Energy Expenditure (EEE)
Low Energy Availability is when EA is <30 kcal per kilogram of fat free mass per day
Let us consider an example. Imagine an athlete is on a calorie restriction diet and then goes all out on a very intense and long duration exercise. The body will have little energy leftover after exercising. If she has an "energy availability" of less than 30kcal per kilogram of fat free mass, by definition she has “low energy availability” to maintain bodily functions to stay healthy. These may include maintaining reproductive hormones, muscle mass, bone health, metabolic processes and immune function.
Now that the body is on a limited energy budget, can you imagine how it allocates the little available energy to various essential functions? Should the body skimp on muscle repair, or slow down bone formation, reduce metabolic rate, or suppress hormone production. Can you imagine the likely consequences of LEA?
Acute versus Chronic LEA
Another relevant point is to consider the energy imbalance (or deficit) over time, and there is a difference between acute or chronic LEA. If you are an ultra-runner, I’m pretty sure you have experienced acute LEA as it is very hard to maintain energy balance during long duration exercises. Most athletes can usually catch up on the deficit in days following the events. This is exactly why post-race recovery nutrition is extremely important, it’s well beyond protecting or repairing your muscles or bones for the next training cycle.
Chronic LEA is a situation when an athlete consistently fails to catch up with calorie deficit for an extended period, maybe weeks or months or even longer. The body responds to chronic LEA with suppression of reproductive hormones (e.g. estradiol/ oestrogen), which can lead to
Functional Hypothalamic Amenorrhea (FHA) or missing periods for 3 months or longer
Greater risks of stress fractures or bone injuries
Adverse impact on health and athletic performance
How is Hormone Suppression Related to Bone Health?
Bone health is very much related to our reproductive hormones. The female hormone oestrogen is needed for bone formation (bone formation = making bones, as opposed to bone resorption). The lower level of oestrogen is why menopausal ladies are at greater risk of osteopenia and osteoporosis.
As female reaches menopause, her production of the sex hormones oestrogen declines, thus affecting the rate of bone resorption vs bone formation. Most people reach peak bone mass in their late twenties. This unfortunately means that as we age, the rate of bone resorption will gradually exceed bone formation. Our bone mineral density inevitably declines as we get older. Any unnecessary bone loss, injuries or fractures that occurs later in our lives tend to be much harder to recover and those damages are potentially permanent.
As you may see, LEA-related FHA (missing periods driven by suppression of hormones from LEA) can impact bone health with greater risk of bone injuries. Potential damage can be long term and can have consequences on an athlete’s health, interrupting their training, sense of well being, training adaptation and ultimately athletic performance. It is therefore very important we take care to avoid LEA in the first place.
Who Is At Risk of LEA?
As you can imagine, those at risk of LEA include athletes in
aesthetic sports such as ballet, gymnastics, figure skating, synchronised swimming
weight class sports such as rowing, boxing, weight lifting
endurance, gravity sports such as running, swimming, cycling, triathlon.
Can LEA occur with or without Eating Disorder?
Remember this question was in the survey? No matter what your answer was, let’s get this cleared up.
LEA
can be driven by inadequate intake and/or excessive energy expenditure,
can happen intentionally or unintentionally,
can happen with or without disordered eating.
An athlete can end up with LEA by either one or a combination of (i) not enough food and (ii) too much exercise. Sadly, LEA can happen inadvertently without eating disorder, which means it can go unnoticed for a while.
LEA Can Occur with Or Without Disordered Eating
Many people think (reasonably) that disordered eating or eating disorder can lead to LEA. However, there are many occasions that an athlete unintentionally fails to consume sufficient calories. Or the athlete inadvertently expends too much energy due to a very demanding training schedule. The athlete may not have access to proper nutrition suitable for their exercise/ schedule as they go about their busy day of work, studies, family responsibilities and social commitments.
Why Are Endurance Runners Susceptible to LEA?
I am not ruling out some undesirable eating behaviour or exercise addiction might be going on amongst some runners. One of my research hypotheses was to test the relationship between eating behaviour and the risk of LEA in runners. (See research poster for a summary of research findings.)
Even in the absence of either eating disorder and/or exercise addiction, there are many scenarios where LEA can happen. First, most runners do not go running on a full stomach (maybe there are some exceptions?). Second, trail running involves training for long hours in remote locations with limited access to food. There are not usually cafes and restaurants on the trails. Most runners don’t tend to stop for hour-long meals in the middle of a long trail run (does anyone?). Third, many tend to get appetite suppression during and post exercise. Once the hunger sets in after a workout, it is almost practically impossible to replenish the accumulated calorie deficit in one sitting. Fourth, gastrointestinal issues can make some runners feel full or nauseous and unable to eat during their runs. Fifth, I can go on and on and on….
What to do about the calorie deficit?
Have you ever figured out how much you would need to eat for an ultra? Do you have a nutrition strategy for your tapering and your race? Are you consistent with your intake during your run? Is there one recovery meal that is enough to make up for the main meals missed, snacks and all the extra energy expenditure from the running?
So many questions! There are many things you can do to improve your running nutrition. If you want to know more and put into practice, please sign up for our nutrition programme for trail runners. The programme contains a series of five webinars covering topics from hydration, pre-race, race and post-race recovery nutrition. Sign up now!
What are the Warning Signs of LEA
Obviously, I cannot finish this piece without mentioning the warning signs of LEA. These are symptoms that MAY be related to LEA. I am sorry this is confusing, but it’s important to note there are other things that can cause the same symptoms as LEA (we call this false positives). If you’ve read this far down, you probably care about having a strong body and resilient health so you can enjoy this sport and life in the long run.
Since you know LEA is driven by either or combination of inadequate intake and excessive exercise, if you feel you may be at risk, look out for the following symptoms:
irregular or missed periods
unexplained fatigue
frequent or unexplained or repeated bone related injuries or fractures
slow recovery
decreased speed, strength or endurance
mood swings
hair loss etc.
Please do consult your doctor and medical professionals if you have any concerns.
Prevention of LEA
Do you know that about 75% of female endurance runners in my study sample were never or rarely happy with her weight? My ladies, be happy with your body and weight as it is truly amazing! Only a small fraction of the world’s population can run long distances like you.
The key to prevention of LEA is to take care of your body, love your body and appreciate that it deserves attention and quality nutrition for doing even more extraordinary and amazing things.
Following are a few more tips for LEA prevention:
Track your periods - note for longer cycles or absence
Stay hydrated
Be aware that prolong exercise can suppress appetite, ensure adequate carbs & proteins to support recovery
Focus on nutrient dense food and gastrointestinal health
Avoid comparing your body with others
Focus on what your body can do as opposed to what it looks like
Consider your long-term health beyond your current athletic performance
Free Webinar on LEA
If you are keen to know about my research project, please sign up for a free webinar on LEA. This is intended to be an interactive session where I will describe the study aim, methodology, results and implications. It is an opportunity for us to discuss, debate and share ideas about LEA, female athlete triad with high relevance for menopausal ladies.
My Research Project on the Risk of LEA
I don't quite want to end the discussion here, so please sign up for the webinar and we can discuss more. In the webinar, I will go through my research project, the aims, hypothesis, methodology, findings and implications.
In very quick summary, I attempted to find out whether three potential risk factors could help us screen for the risk of LEA in endurance runners. The three variables in the study were exercise volume, eating behaviour and knowledge of LEA. If you really can't join the webinar, I'd recommend reading the research abstract below.
Below I am sharing a few relevant files related to my research project. Bon appetite!
Abstract of my research report
Project poster presentation (PDF)
Questionnaire used for this study (goole form in pdf)
Low Energy Availability in Female Questionnaires (LEAF-Q) (Melin et al, 2014)
LEAF- Q Scoring card (Melin et al, 2014)
Female athlete screening tool (FAST) (McNulty et al., 2001)
References
The Female and Male Athlete Triad Coalition https://femaleandmaleathletetriad.org/
Burke, L. M., Lundy, B., Fahrenholtz, I. L., & Melin, A. K. (2018). Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes. International Journal of Sport Nutrition and Exercise Metabolism, 28(4), 350-363. https://doi.org/10.1123/ijsnem.2018-0142
Condo, D., Lohman, R., Kelly, M., & Carr, A. (2019). Nutritional Intake, Sports Nutrition Knowledge and Energy Availability in Female Australian Rules Football Players. Nutrients, 11(5), 971. https://doi.org/10.3390/nu11050971
De Souza, M. J., Nattiv, A., Joy, E., Misra, M., Williams, N. I., Mallinson, R. J., Gibbs, J. C., Olmsted, M., Goolsby, M., & Matheson, G. (2014). 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad: 1st International Conference Held in San Francisco, CA, May 2012, and 2nd International Conference Held in Indianapolis, IN, May 2013. Clinical Journal of Sport Medicine, 24(2), 96–119.
Elliott-Sale, K.J., Tenforde, A.S.; Parziale, A.L., Holtzman, B.; Ackerman, K.E. Endocrine effects of relative energy deficiency in sport. (2018) International Journal of Sport Nutrition Exercise and Metabolism, 28, 335–349.
Fahrenholtz, I. L., Melin, A. K., Wasserfurth, P., Stenling, A., Logue, D., Garthe, I., Koehler, K., Gräfnings, M., Lichtenstein, M. B., Madigan, S., & Torstveit, M. K. (2022). Risk of Low Energy Availability, Disordered Eating, Exercise Addiction, and Food Intolerances in Female Endurance Athletes. Frontiers in Sports and Active Living, 4, 869594–869594. https://doi.org/10.3389/fspor.2022.869594
Fahrenholtz, I. L., Sjödin, A., Benardot, D., Tornberg, Å. B., Skouby, S., Faber, J., Sundgot‐Borgen, J. K., & Melin, A. K. (2018). Within‐day energy deficiency and reproductive function in female endurance athletes. Scandinavian Journal of Medicine & Science in Sports, 28(3), 1139–1146. https://doi.org/10.1111/sms.13030
Folscher, L.-L., Grant, C. C., Fletcher, L., & Janse van Rensberg, D. C. (2015). Ultra-Marathon Athletes at Risk for the Female Athlete Triad. Sports Medicine - Open, 1 (1), 29. https://doi.org/10.1186/s40798-015-0027-7
Kuikman, M. A., Mountjoy, M., & Burr, J. F. (2021). Examining the Relationship between Exercise Dependence, Disordered Eating, and Low Energy Availability. Nutrients, 13(8), 2601–. https://doi.org/10.3390/nu13082601
Lichtenstein, M.B., Melin, A.K., Szabo, A., Holm, L (2021). The Prevalence of Exercise Addiction Symptoms in a Sample of National Level Elite Athletes. Fronters in Sports and Active Living, 3:635418. doi: 10.3389/fspor.2021.635418
Lichtenstein, M.B., Hinze, C.J., Emborg, B., Thomsen, F., Hemmingsen, S.D. (2017). Compulsive exercise: links, risks and challenges faced. Psychology Research and Behaviour management, 10:85-95. https://doi.org/10.2147/PRBM.S113093
Logue, D. M., Madigan, S. M., Melin, A., Delahunt, E., Heinen, M., Donnell, S.-J. M., & Corish, C. A. (2020). Low Energy Availability in Athletes 2020: An Updated Narrative Review of Prevalence, Risk, Within-Day Energy Balance, Knowledge, and Impact on Sports Performance. Nutrients, 12(3), 835. https://doi.org/10.3390/nu12030835
Logue, D. M., Madigan, S. M., Heinen, M., McDonnell, S.-J., Delahunt, E., Corish, C.A. (2019). Screening for risk of low energy availability in athletic and recreationally active females in Ireland, European Journal of Sport Science, 19 (1), 112-122, DOI: 10.1080/17461391.2018.1526973
Logue, D., Madigan, S. M., Delahunt, E., Heinen, M., Mc Donnell, S.-J., & Corish, C. A. (2018). Low Energy Availability in Athletes: A Review of Prevalence, Dietary Patterns, Physiological Health, and Sports Performance. Sports Medicine (Auckland), 48(1), 73–96. https://doi.org/10.1007/s40279-017-0790-3
Loucks, A. B., & Thuma, J. R. (2003). Luteinizing Hormone Pulsatility Is Disrupted at a Threshold of Energy Availability in Regularly Menstruating Women. The Journal of Clinical Endocrinology and Metabolism, 88(1), 297–311. https://doi.org/10.1210/jc.2002-020369
Magee, M. K., Lockard, B. L., Zabriskie, H. A., Schaefer, A. Q., Luedke, J. A., Erickson, J. L., Jones, M. T., & Jagim, A. R. (2020). Prevalence of Low Energy Availability in Collegiate Women Soccer Athletes. Journal of Functional Morphology and Kinesiology, 5(4), 96–0. https://doi.org/10.3390/jfmk5040096
McNulty, K. Y., Adams, C. H., Anderson, J. M., & Affenito, S. G. (2001). Development and validation of a screening tool to identify eating disorders in female athletes. Journal of the American Dietetic Association, 101(8), 886–894. https://doi.org/10.1016/S0002-8223(01)00218-8
Melin, A.; Tornberg, Å.B.; Skouby, S.; Møller, S.S.; Sundgot-Borgen, J.; Faber, J.; Sidelmann, J.J.; Aziz, M.; Sjödin, A. (2015) Energy availability and the female athlete triad in elite endurance athletes. Scandinavian Journal of Medicine & Science in Sports (25), 610–622.
Melin, A., Tornberg, Å. B., Skouby, S., Møller, S. S., Sundgot-Borgen, J., Faber, J., Sidelmann, J. J., Aziz, M., & Sjödin, A. (2015). Energy availability and the female athlete triad in elite endurance athletes: Energy availability in female athletes. Scandinavian Journal of Medicine & Science in Sports, 25(5), 610–622. https://doi.org/10.1111/sms.12261
Melin, A., Tornberg, Å. B., Skouby, S., Faber, J., Ritz, C., Sjödin, A., & Sundgot-Borgen, J. (2014). The LEAF questionnaire: a screening tool for the identification of female athletes at risk for the female athlete triad. British Journal of Sports Medicine, 48(7), 540–545.
Meng, K., Qiu, J., Benardot, D., Carr, A., Yi, L., Wang, J., & Liang, Y. (2020). The risk of low energy availability in Chinese elite and recreational female aesthetic sports athletes. Journal of the International Society of Sports Nutrition, 17(1), 13–13.
Moss, S. L., Randell, R. K., Burgess, D., Ridley, S., ÓCairealláin, C., Allison, R., & Rollo, I. (2021). Assessment of energy availability and associated risk factors in professional female soccer players. European Journal of Sport Science, 21(6), 861–870.
Mountjoy, M., Sundgot-Borgen, J. K., Burke, L. M., Ackerman, K. E., Blauwet, C., Constantini, N., Lebrun, C., Lundy, B., Melin, A. K., Meyer, N. L., Sherman, R. T., Tenforde, A. S., Klungland Torstveit, M., & Budgett, R. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. British Journal of Sports Medicine, 52(11), 687–697.
Mountjoy, M., Sundgot-Borgen, J., Burke, L., Carter, S., Constantini, N., Lebrun, C., Meyer, N., Sherman, R., Steffen, K., Budgett, R., & Ljungqvist, A. (2014). The IOC consensus statement: beyond the Female Athlete Triad—Relative Energy Deficiency in Sport (RED-S). British Journal of Sports Medicine, 48(7), 491–497.
Nattiv, A., Loucks, A. B., Manore, M. M., Sanborn, C. F., Sundgot-Borgen, J., & Warren, M. P. (2007). American College of Sports Medicine position stand. The female athlete triad. Medicine and Science in Sports and Exercise, 39(10), 1867–1882.
Ravelli, M. N., & Schoeller, D. A. (2020). Traditional Self-Reported Dietary Instruments Are Prone to Inaccuracies and New Approaches Are Needed. Frontiers in Nutrition (Lausanne), 7, 90–90. https://doi.org/10.3389/fnut.2020.00090
Slater, J., McLay-Cooke, R., Brown, R., & Black, K. (2016). Female Recreational Exercisers at Risk for Low Energy Availability. International journal of sport nutrition and exercise metabolism, 26(5), 421–427.
Sharps, F.R.J., Wilson, L.J., Graham, C.A-M., Curtis C. (2022) Prevalence of disordered eating, eating disorders and risk of low energy availability in professional, competitive and recreational female athletes based in the United Kingdom, European Journal of Sport Science, 22:9, 1445-1451, DOI: 10.1080/17461391.2021.1943712
Commenti