Carnivore and Carbs... Again

How many calories do you have on board? Which energy systems use what? How long can you go?

Carnivore and Carbs... Again
Photo by Meggyn Pomerleau / Unsplash

I am not above questioning myself or being wrong.  That's literally how I started this carnivore journey.  I thought the idea was asinine.  I also thought I was in good enough health to try anything for 30 days and see what happens.  I also have enough humility to not admonish something I haven't tried.

I have written on the subject of carbs before (1, 2) and the general consensus I've come to is "no, you don't need carbohydrates for exercise."  However, exercise is not training.

"(exercise) is just moving your body for the sake of exercising.  (training) is exercising in a way to achieve a specific result."
~ Dr. James Dinicolantonio, Win

More on this in a minute, but suffice to say that my training demands have evolved and so must my ideas – lest I'm "just exercising for the sake of moving."  It's nothing personal, but to have a discussion we must operate with clear definitions.

I got a message for a well respected person in the ancestral health scene which got me thinking about this topic again.  While I have experimented with various reintroductions over the past 2.5 years, my opinions on fruit / honey have settled around:

  • I concede that biologically fruit wants to be eaten so that the seeds are spread with a nice pile of fertilizer.
  • Fruit is not a reliable source of nutrients / calories in the wild (annual blooming that yields a few thousand calories).
  • The nutrient or calories / dollar is quite poor compared to meat, eggs, and organs.
  • I have not (previously) seen a performance benefit during reintroduction (though the deltas were small; 20-40g carbohydrate).
Newsletter subscribers be thankful, I had a hissy-fit rant written about "influencers selling the drama", but sent this article out instead.

Context and Definitions:

My training volume has ramped up in recent months to include capacity and aerobic work.  This brings us to another vocabulary lesson – extending from the first.  At the time of writing:

"Workout Days" consist of a minimum of 3 hours of effort with an average heart rate around 60% of MHR (Zone 2).

In my current routine this is done three days in a row (important to note) – not because I think it's the best, but it's when I can get to the gym.  The other 4 days of the week I'm still "exercising", or:

"Exercise" is a minimum of Zone 1 (50% MHR) for less than 60 minutes.

Playing, walking, light technical sport training or general movement (house chores, yard work, etc.) all fit the bill here.

If you're an athlete, you need to be training.  Exercise isn't good enough.

Photo by Bozhin Karaivanov / Unsplash

The pervasive dogma in endurance sports is entrenched in carb-loading.  Though some ketogenic marathoners are making headway.  So, let's be clear what I'm talking about here.  Most fruit / fiber still doesn't sit well with me; though a few things like honey and oranges seem fine even in large doses.

By "large" dose I'm mean ~100 - 150g honey (80 - 100g carbs).   I'm also talking about consuming them post-effort rather than prior – thanks to a quick comment from someone who works that the gym that wrote the endurance program I'm following (3).

With all of that in mind I'm happy to have a discussion and review research and training notes with anyone – with the caveat of performance being king.  Health, of course, is a matter of longevity, not necessarily performance (i.e. healthy-user / high-performer bias).

"Show me yourself after 12 hours of continuous effort and I won't need to tell you who you are."
~ Mark Twight, Poison

Napkin Math:

With carb-loading (86% of calories from carbohydrate) your body may store up to 15g of glycogen / Kg of body weight (4).  This is regarding lean body mass (LBM) which varies slightly depending on how you calculate it (5, 6) – technically in this context the figure should not include skeletal mass which it is in the second calculator link.

170 lbs (5'8" Male), 7% Body Fat
LBM1: 58.3 Kg
LBM2: 70.2 Kg

Computing glycogen at 15 g/Kg:

58.3 Kg * 15 g/Kg = 874g glycogen
70.2 Kg * 15 g/Kg = 1,053g glycogen

Each gram of glycogen has about 1 Kcal (calorie) of energy (7), so let's call the average about 1,000 calories from glycogen stored in my body – and that's if I'm consuming 85% carbohydrates (!).

Someone will surely point out that you can store orders of magnitude more calories as fat (3,500 / lb); which is why I included a body fat percentage.  Also note that you need at least 3% body fat to stay alive (8).

So, if you're real anal...

7% current - 3% minimum = 4% fat to lose
0.04 * 170 lbs = 6.8 lbs of fat to lose
6.8 lbs * 3,500 calories = 23,800 calories of fat

And for the fasting zealots:

23,8000 calories / 4,000 calories per day = 5.95 days before I absolutely die!

Cronometer estimates "wrestling" at 400 calories / hour; which is pretty accurate in my opinion if you're going at moderate pace and alternating on-off rounds.

Grappling @ 300 - 400 calories / hour

Per FitBit, I've logged 1,700 calories in 90 minutes before – though that figure includes base metabolic rate (BMR).

Grappling: 300 - 400 calories / hour
BMR + Cardio: 500 - 600 calories / hour
BMR + Grappling + Capacity Training: 1,133 calories / hour

Bringing everything together then, if:

  • I were eating 85% carbohydrates (to maximize glycogen stores at about 1,000 calories) and...
  • My BMR and training (again, not just exercise) consumed a conservative 500 calories / hour...

I've got 2 hours before my glycogen stores are depleted.  Those are huge "ifs" though.  Realistically, I'm going in to training with a blood glucose (BG) from 80 - 100 (obviously not "carb loaded").  With the previously outlined "workout / training day" definition I'm looking at a maximum of 2 hours of grappling – conceding it's not 100% glycolytic.

But, what then?  I'm not finished after 2 hours?  No.  There is an argument for metabolic flexibility here as I realize "cardio" (Zone 2 / Zone 3) training isn't glycolytic and ketones / fat stores can be tapped after glycogen has been depleted.

However, my curiosity is:

...In the context of LONG training days (3+ hours) utilizing MULTIPLE ENERGY systems for CONSECUTIVE days.


I was going to collect data samples and compare them to my previous research (below, and on GitLab (9)), but my curiosity has largely been satisfied.  Recalling my earlier work re-affirms the value of intuition.

My initial analysis (10) didn't include data on carbohydrates, only fat:protein ratio (negatively associated with performance, r = 0.44, p = 0.0022).  Also note that:

  • Mood had a positive relationship with performance (r = +0.51, p = 0.0035).
  • AWQ had a positive relationship with performance (r = +0.48, p = 0.0063).

In short, to perform well:

  • Be / get in a good mood (the mind is secondary, the body tertiary).
Before his Olympic bronze medal run, at the age of 32, wrestler Terry Brands was told by legend Dan Gable: "What you gotta do is only do things that make you feel really good, so that you can get ready to train really hard only when you feel really good."

Since there's about 50g of glucose made from 100g of protein (11) and I generally get well over 200g protein, it's not an unreasonable hypothesis that the above correlation between protein (via fat:protein ratio) and performance could (partially) be attributed to glucose production (via gluconeogenesis) – but again, I didn't run that data.

  • To perform well, you also need to recover as hard as you train (duh).
Sleep better to reduce your heart rate and improve AWQ, and do a little mild fasting.  The non-duh part was that protein correlated positively with heart rate, possibly a carryover effect from high-protein to drive performance the day prior – e.g. higher heart rate after a hard training day.

Conclusion... For Now:

If you're going to eat carbohydrates, you don't need to justify it to anyone except yourself.  So do it, with effort, paid ahead of time – don't buy on credit.  Hopefully your own health and performance matter more to you than what fits nicely into someone else's niche categorical definition – including my own above!

Use this information though:

  • If you're not hitting Zone 2 (60% MHR) then you can get by without carbs.  It's at this range where your body burns equal parts sugar and fat.
  • Mood and Stress are significant factors in performance.  When you feel good, you generally perform well.  Human biology does have a serotonin response to carbohydrates (12).

Coming full circle then, what probably makes you feel good is performing well, and for a longtime – so the "health" (e.g. longevity) aspect of "fitness" (what are you actually fit for?) is still relevant.

Are carbohydrates necessary, no.  Neither is high-performance – see my thoughts on moderation (13).  This is where the "X isn't necessary" or "so-and-so does / doesn't do this-or-that" argument leads.

What are you doing?  How well?  How long?  Are you selling yourself short on what you could be capable of based on what someone who doesn't even know you says you should do?

Break the rules.  Stay curious.  Learn.  Leave.  Grow.  Clap for yourself.  Accept no consolation and do whatever it takes to keep moving forward.

On Fasting: For the sticklers, I likely wouldn't literally die on a 6-day fast because muscle tissues would start to be cannibalized for fuel.  At any rate, this is far from an ideal performance enhancer so you get the point.
Update 8/21/22: Someone forwarded me an article saving me the statistical grunt work showing that under the right conditions you can consume 200g of carbs / day and still be in ketosis.
Update 8/24/22: Dr. James Dinicolantonio sums this up nicely in his book Win, pg. 192-204.  The long-short is that "earning your carbs" requires > 70% VO2max; but low-carb diets increase the threshold (% of VO2max) where you start burning carbs – however, there was "no difference in glycogen depletion after 180 minutes."  So, I was generous suggesting 120 minutes @ 60%; if you're a real stickler, do 180 minutes at 70%.

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