Energy Availability Model

Nutrition Q&A [Moderated]
1

On some of the endurance podcasts, the Energy Availability (EA) model is making the rounds. I know it’s been around for a minute I thought I’d look into it.

One thing I notice is it consistently recommends more calories per day than using CICO calculators even if you include things like TEF. . . often by not a small amount, as much as 400-600 calories.

I’ve used CICO trackers like Cronometer effectively. I’ve been trying MacroFactor which is more of an adaptive, dynamic tracker. It tracks calories consumed and the rolling mean of your scale weight to predict the calories you need. . . seems reasonable, but my caloric needs, I think, are two variable to make this a good fit for me. My caloric needs can swing from more than 5k to a little over 2k depending on a long endurance or rest day.

My cursory understanding the research into the EA model is they tracked various health markers and when they began to go suboptimal or critical, including scale weight, and used it to derive a relative caloric need scaled by FFM…45kcal/kg for women and 40kcal/kg for men.

I know nutrition and caloric needs are notoriously fuzzy around the edges. But this approach seems better than a reductionist approach. Any missed contributor in a reductionist CICO approach would contribute to the variance. A scale factor would ostensibly capture these since you don’t care what they’re needed for, only the quantity. . . . assuming you’re measuring the right indicators (maybe a big assumption).

Not the best evidence, but it is what the pro endurance teams are moving to…kind of part in parcel of the move from training at caloric deficit to feeding for sustained caloric energy surplus…e.g. fueling the rid with massive carbs. Which I think does have decent evidence behind it.

Point of the post…what does BBM folks have to say? On to something? Yet another sports nutrition fad? I did a podcast archive search and didn’t see anything touching on it.

2

The targets you mentioned, specifically the 30 Cal/kg FFM/d target, for Low Energy Availability are derived from short-term laboratory experiments in young women, where various surrogate markers like LH, IGF-1, and so on were monitored in response to various energy intake levels.

A few important caveats:

  • They’ve not been adequately investigated in men
  • There is substantial noise in all of the variables (energy expenditure, energy intake, FFM, etc.)
  • The LEA to RED-S connection assumes a causal relationship, which has some gaps in it

Anyway, it’s mostly a model, but not really practically useful. When investigated, many people don’t have symptoms of LEA when < 30, and some people have persistent symptoms when >45. I think the best use of LEA in practice is to screen for disordered eating before working with individuals. I don’t think this model is otherwise practically useful for athletic performance , though I do agree trying to consume more energy during prolonged bouts of endurance training is a good idea up to a point.

We’ve done a podcast on LEA/RED-S, but not on intraworkout carbohydrate supplementation just yet.

One thought, and no pressure, but if you have questions like this you’d like us to do deep dives on, you may benefit from becoming a Barbell Medicine Plus member. We answer questions like this from our subscribers each month, along with ad-free listening, product discounts, etc.

1 Like
3

I ran into some of the limitations you mentioned in the research too.

So, is it still the old CICO model for answering the question “how many calories do I need today?”

4

I wouldn’t position EA against CICO, as they are the same at their core. It’s hard to figure out both, as there are multiple dynamic variables involved. CICO is always the law though, no matter what.

1 Like