Low Energy Availability Surrogates Correlate with Health and Performance Consequences of Relative Energy Deficiency in Sport

The British Journal of Sports Medicine, June 2nd, 2018

Ackerman, Et. Al    

Female Athlete Program, Division of Sports Medicine, Boston Children’s Hospital, Boston, MA

The Female Athlete Triad is an unfortunate too-often-encountered phenomenon in female athletes. In fact, many of us have even wrestled with this in our own athletic careers. In physically active women, the condition presents as a continuum with respect to energy availability (dietary energy intake – exercise energy expenditure), the status of menorrhea, and bone health.  Taking this concept to another level, the International Olympic Committee (IOC) expanded the female athlete triad to a new term, Relative Energy Deficiency in Sport (RED-S), in order to capture it’s wide-ranging systemic and physiological effects on the body. Low energy availability (low-EA), a major component of the female athlete triad and RED-S, has been linked to increasing the risk of infection, illness, injury, fatigue, and nutrition deficits in athletes.

What The Study Looked At

In this study, the authors explored the role of low-EA in the health and performance domains of RED-S in female athletes. 1000 female athletes, ages 15-30 years old, filled out online questionnaires with questions related to different domains of the RED-S for health and performance.  Eating disorders (ED) / disordered eating (DE) served as a proxy/surrogate for low-EA. To help categorize the participants with low-EA, three different standardized outcome measures were completed that detected the presence of ED / DE.

How The Results Shook Out

Out of the 1000 participants, 47% were classified as having low-EA. The low-EA crowd had increased risk in all of the RED-S negative health consequences with the exception of the immunological and growth/development domains. In the presence of low-EA, the physiological systems at highest risk (odds ratios) for dysfunction were:

• Metabolic 3.01 x
• Cardiovascular 2.53 x
• Psychological: 2.41 x
• Menstrual Function: 1.93 x
• Bone Health 1.72 x

As you could imagine, the odds of subjective negative performance effects weren’t so great in those with low-EA, the highest risk areas being:

• Impaired Judgement 4.33 x
• Depression 2.29 x
• Decreased Training Response 2.13 x
• Decreased Concentration 2.01 x

Interestingly Enough…

No difference was seen in injury risk between those classified with low-EA and adequate-EA…however…

• Low-EA has previously been linked with increased risk of injury in several other studies
• Negative effects in the bone health domain were present in this study
• All participants were already reporting to a medical center with a medical complaint of some form, therefore some selection bias could be present

In another surprising finding, the low-EA group had a higher average BMI than the adequate-EA group (23.8 vs. 22.2). This might suggest that body composition may be more important than total BMI. More importantly, those suffering from the negative consequences of low-EA / Female Athlete Triad may be easily visible to us! We have to move past the stereotyping of victims of Female Athlete Triad as strictly “too skinny runners.”

Three Takeaways

1.  Understand that low energy availability (how much calories you take in vs. how many you expend with activity with respect to fat-free mass) has wide-ranging negative systemic health and performance consequences.
2. Female Athlete Triad isn’t always visibly present in someone’s appearance. Ask your female athletes and patients about their nutrition/energy intake and training load.
3. If you work in the sports world, encourage your sports medicine team to utilize pre-season screening and outcomes for eating disorders / disordered eating for female teams that could be at risk. Follow up with a multi-disciplinary approach to mitigate these risks as much as possible.

Thank you for your support and tuning in this week!

Tyler Cope

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