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Energy Availability: Is It Useful to Calculate?

Is your athlete:

  • Chronically sick?

  • Lacking a regular period?

  • Losing weight unintentionally?

  • Increasing their training (volume and/or intensity)?

  • Purposefully dieting for weight loss?

  • Only eating healthful foods?

  • “Too busy to eat”?

  • Skipping meals?

  • Suffering from frequent stress fractures?

  • Taking longer than normal to recover from an injury?

  • Seeing dips in strength or performance?

  • Irritable?

  • Fatigued?

  • Lacking coordination or concentration?

Lengthy, right?

These are only a few of the signs, symptoms, and risk factors of low energy availability (LEA).

What’s Low Energy Availability (LEA)?

It’s the energy remaining after those expended from exercise have been accounted for.

These “leftover” calories are needed to fulfill exercise recovery (e.g., muscle repair and building), maintain bone health, support the immune system and a regular menstrual cycle, plus much more.

The energy availability equation is dependent on knowing an

athlete's fat-free mass.

If you don’t have enough fuel to drive all of these bodily processes, the brain begins to cut corners. Hence, the lengthy list above.

Keep in mind that LEA can be intentional or unintentional:

  • An intentional LEA could include purposeful dieting for weight loss or making weight for a sport, restrictive eating and disordered eating practices, or eating disorders.

  • An unintentional LEA could include increased intensity of or volume of training without scaling up calories consumed, skipping meals due to a busy work or school schedule, or food insecurity.

Plus, LEA can fluctuate throughout the competitive season.

Consistently feeling exhausted during workouts? You may be suffering from LEA.

Source: World Rowing

The Energy Availability Calculation: Great Idea, but…

LEA is hard to calculate due to multiple factors needed to complete the equation.

The left-hand side of the equation:

  • It requires detailed food records: Calculating energy intake requires meticulous food records over multiple days. Are you able to educate your athlete how to measure and record their intake? Is your athlete willing and motivated to do so? Dietary intake would need to be frequently evaluated as nutritional therapy continues its course.

  • It requires precise energy expenditure measurements: When athletes train during a session, they're stopping and going, taking water breaks, and are varying their intensities--they aren't swimming at the same pace, non-stop for 60 minutes. Plus, sessions change on a daily basis. So how will you accurately measure how much they’re burning?

The right-hand side of the equation:

  • You need fat-free mass (FFM): But what if your team doesn’t have access to body composition testing? Or even wants to? How often could you feasibly measure FFM throughout the year for an athlete? Will the athlete’s body composition drastically shift within your monitoring timeframe that will change the right-hand side of the equation?

  • The LEA cut-offs don’t consider gender or sport: The research reports LEA is defined as providing less than 30-45 kcal per kilogram body weight of FFM. This cutoff reminds me of the effectiveness of the body mass index.

To complicate matters even more, the population studied to create the 30-45 kcal/kg FFM cutoff was untrained women.

Not athletes.

Not males.

Take-away Message: Practically Evaluate LEA

So now that your equation hopes have been extinguished, how can you evaluate an athlete for LEA and help them reconsider food intake? I like to think of it as piecing together clues.

  1. Fix LEA by increasing caloric intake or decreasing training load: Likely the latter will be difficult for a coach or athlete to accept. I’ve found that educating athletes on this ultimatum is a successful way to convince them to eat more and pay attention to scheduled snacks and meals.

  2. Keep your ears and eyes open to the signs, symptoms, and risk factors listed in this post’s introduction: Again, piece together clues. Every athlete will present differently.

  3. Build relationships with coaches and support staff: They’re with the athletes the most and will be able to flag injuries that won’t heal, undesirable weight loss, and chronic sickness. Plus, they can keep you in the loop for when practices become more intense or frequent.

  4. Weight loss is a sign of LEA, but LEA can exist without weight loss: Educate athletes on this. It’s common to think that weight maintenance means “calories in, calories out.” It doesn’t.*

  5. Probe athletes to learn of LEA contributors: Again, is it the training schedule? Is LEA unintentional or intentional? Are athletes rushing from practice to class and not recovering adequately? Is it food insecurity? If you know the root of the problem, it’s easier to create a realistic solution.

Here are a few resources that may be helpful:

* LEA can lead to a suppressed basal metabolic rate—or those calories burned in order to fuel the body's basic demands if you were to lay in bed all day doing nothing—that will mitigate weight loss and promote maintenance. This scenario, too, is not good.


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