How to Fuel Ultra-Distances: The World’s Toughest Mudder

A couple weeks ago, I received an enthusiastic email from a group of Aussies. They were planning on competing in the World’s Toughest Mudder (WTM), a perversely-warped, extreme version of the regular Tough Mudder that has contestants complete as many 8-10 mile circuits as they can in a single 24-hour period. To get the spot in the WTM, their four-man team had to place in the top 5% of finishers in the Melbourne Tough Mudder, so they aren’t physical slouches by any means. They’re also Crossfitters, rugby players, and avid Primal eaters. Simply put, these guys make us real proud.

They weren’t writing just to say “hi,” however. They also needed Primal fueling advice, especially since the guy who won last year’s WTM ate anything but Primally. For a single, one-time, all-out event, I’d actually say that making concessions with your diet are fine, but these guys weren’t having it. They wanted to stay Primal for the duration and avoid all the sugary gels and extruded pasta in a vacuum bag (yes, people are really eating this).

Did I already say they make us proud?

Well, is such a thing even possible? And if so, how would you go about doing it?

Let’s read the relevant portion of their email before we begin:

Hi Mark,

On the 31st of March 2012, myself and a team of mates competed in Australasia’s first ever Tough Mudder race on Phillip Island in Melbourne, Australia. Tough Mudder is a 20km obstacle course race designed by British Special Forces which tests endurance, strength, mental commitment and teamwork and is one of around 30 events held annually across the globe.

Out of the 26,000 entrants in the Melbourne event, my team and I managed to finish in the top 5% of all finishers and subsequently have been selected to go to the world championships in Englishtown, New Jersey, USA. The world championships puts the world’s most hardcore Mudders through a grueling 24-hour challenge designed to find the toughest team on the planet. When the mud settles on November 18th, 2012, a select few winners will have bested 500,000 others worldwide for the right to call themselves the World’s Toughest Mudders.

Like any good team about to undergo a huge challenge we have been researching the event and preparing mentally and physically. As Primal eaters we are obviously interested in diet. Last week we found the winning athletes’ diet (Junyong Pak) from 2011 below is his advice and Race Diet plan (I think this much sugar could kill all 4 of us!)

‘In addition to Powerbar gels, I decided to supplement with canned fruit in heavy syrup, pasta, PB&J, protein drink, gatorade, honey, eggs, and bananas. I forgot to eat the honey, and did not make eggs or bring bananas but ate everything else. The canned fruit (peach chunks, halved pears) was a huge winner. I packaged these into vacuum seal bags such that each bag contained half a can of fruit, or 175 calories. These were robust bags that did not break, relatively compact, and also supplied some of my water intake. I could bite off a corner of the bag without taking my gloves off and bite the fruit out like a gel. I packaged the pasta in similar fashion with much success.’

Mark, as you can see, I think if we did this we would all be in a sugar coma and never wake up. Can you help us come up with something Primal to fuel us through the race?

4 Man Team:
James Laird: 28 yrs, 6’2″, 95kg
Scott Laird: 25 yrs, 6’1″, 80kg
James Stiles: 28 yrs, 6’2″, 88kg
Marc Burbrough: 25 yrs, 6’4″, 92kg

Thank you and regards,


Here’s a video of the guys in action to give you an idea of what they’re up against:

It’s gonna be like that, only crazier, and performed multiple times across the day.

First of all, hats off to them. If I had to do another ultra endurance event sometime in my life, the World’s Toughest Mudder would probably be high on my list. It looks like good, clean (well, dirty, actually) fun. It may be fun that takes a week to recover from, but fun nonetheless.

Second, the WTM is not just an ultra-endurance event. With some 24 obstacles ranging from sprints up steep muddy hills to climbing towers and vaulting over walls to swimming through ice-water (and plenty of as-yet unannounced obstacles), you’re not just going to chill out in the oxidative energy pathway, burning fat for energy. The bulk of your energy can – and will, if you take the necessary steps – come from fat, but defeating most of those obstacles (over and over again across 24 hours) will also require intermittent forays into the ATP-PC and anaerobic pathway. Your nutrition, then, has to take both aspects of the race into account.

A month or two before the race:

Become a fat-burning beast.

This may not be a stretch for you bunch, seeing as how you’re already following a Primal eating plan. If you are fat-adapted, stay adapted. If you aren’t, get fat-adapted. Being a fat-burning beast will help you efficiently burn all that body fat for energy (and even the lean among us have enough body fat to provide energy for a 24 hour ultra distance event) and hold off on burning glycogen until you really need it. Doubleplusgood. If you aren’t already adapted, I would recommend limiting your daily carb intake to around 60-70 grams in the months leading up to the race. This will train your body to rely on fat for energy while sparing glucose.

Titrate down your Crossfit metcons.

I know, I know – if you’re like most CrossFitters, you get off on the metcon intensity, and you owe a lot of your physical prowess to training that way. But those metcons burn through glycogen like crazy, and if you continue to follow the 3 on, 1 off (or even 2 on, 1 off) workout schedule without upping the carbs, you’re going to burn yourselves out. Keep the metcons to once, maybe twice a week, shorten them up considerably (5-10 minutes instead of 20-30 minutes), and up the intensity while reducing the volume. Make sure to do some simple, basic, low-rep, low-volume, high-intensity, low-stress strength work instead.

A couple days before the race:

Fill those glycogen stores.

But Mark… didn’t you just say to go low-carb to maximize our bodies’ fat-burning and glucose-sparing potential? What gives? Simple. Two days of (healthy Primally sourced) carb loading to the tune of 350 grams or so per day will top off your glycogen stores. Since you’ll be getting your carbs from whole food sources like sweet potatoes, potatoes, squash, fruit of all kinds, and, if you swing that way, rice, you may have to eat what seems like a large amount of food. It’s not, not really. People act like it’s impossible to eat carbs while eating Primal, and I don’t get it. Just reach for the tubers and fruit.

Take it easy.

Don’t CrossFit, don’t lift, don’t do much of anything that will sap your stored energy and exhaust your muscles. Go for a walk, work on mobility, do some yoga, or do nothing at all. Enjoy your (brief) time off!

Race day:

Eat a light breakfast.

Couple strips of bacon, a couple eggs, some fruit, and strong coffee. This will give you a bit of something in your stomach without weighing you down, and the coffee will liberate some fatty acids for use during the event (not that you need help with that).

Eat some medium chain triglycerides (MCTs).

Why MCTs? They can’t be stored, meaning they must be utilized for energy. MCTs also increase the production of ketones. These are good things, since fat is going to be your ticket through this race. In most cases, I’d tell you to get your MCTs from a whole food source, like coconut oil. Not today. Today, I want you to take three tablespoons of pure, unadulterated MCT oil. If the thought of that appalls you, try frothing it up in your coffee.

Drink some salty broth.

Broth, especially homemade broth dosed with plenty of sea salt, provides easily-assimilable electrolytes like sodium, calcium, and magnesium. You’re going to be excreting a lot of sodium, so add 2-4 grams of sodium. Not salt, but sodium. Hey, didn’t I say to drink salty broth? For reference, sea salt is about 1.8 grams sodium per teaspoon, while table salt is about 2.3 grams sodium per teaspoon.

During the race:

Keep a fat source at hand.

MCT oil, nut butter, and coconut oil are squeezable and fat-rich. Maybe toss in some hard-boiled eggs for protein and fat.

Keep a slow-digesting carb source at hand.

Peter Attia, the endurance athlete who’s been training in a ketotic state for months now, recommends Superstarch, a non-GMO cornstarch that provides steady, even glucose. Best of all, Superstarch doesn’t spike insulin, especially when compared to maltodextrin, so you can take it during a race without impacting your ability to burn fat.

If you can’t get your hands on Superstarch, plain cornstarch (not maltodextrin, which is absorbed too quickly and results in too large an insulin spike) will work tolerably well.

Keep an energy drink on hand.

I recommend the molasses/honey/coconut water hybrid mentioned in this post. Consider mixing in more sea salt for sodium, too, as you’ll be excreting tons of that.

That’s what I’ve got. The key to doing this thing in a low-carb state, of course, is that you are completely fat-adapted. Becoming a fat-adapted fat-burning beast will make you or break you. Choose wisely, my friends, and be sure to let us know how you do! Grok on!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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