Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
7 Dec

How to Fuel a Marathon

Having yielded to those of you who still insist on running a marathon, yesterday I offered a training strategy that gets you the best results with the least amount of damage. Today’s post is about fueling a marathon – what food to eat and when to eat it. It’s not solely about race day nutrition, because if you just focused on what to eat the day of the race, you’d be missing out on a lot (and you’d likely have problems finishing, or at the very least your performance would suffer). It’s about what to eat while training, a few days before the race, and the day of the race itself. This is the stuff I would do if I had to go back and do another marathon with my current knowledge. I might tweak things slightly if I was trying to make the Olympics, but for the average, relatively fit Primal dude or gal who wants to check this off their bucket list? This is the perfect way to fuel your efforts. And this works equally as well for those of you who think a century ride (100 miles on a bike) might be in the cards.

First, let’s examine what to do while you’re training. What do you eat? How much of it do you eat? Low-carb, high-carb?

Train Low, Race High

For the layperson, “train low, race high” is basically a way to teach your body to do without a glut of glucose for longer periods of time. By training low on glycogen, your body grows accustomed to running on fat and conserving muscle glycogen. By training low and then racing high – with topped-off glycogen stores in your muscles – you experience a big boost in performance on race day. You’ve built up your ability to access body fat during a run, and that doesn’t go anywhere, but now you’ve suddenly got 400+ grams of muscle glycogen at your disposal. Glycogen that you’ve learned to access efficiently, rather than squander all at once. That’s huge, especially for 26.2 miles.

It’s reasonable to think that Grok often “trained low.” If low-level physical activity in a glycogen-depleted state was the norm for much of human evolution – as I think it probably was – it makes sense that its emulation in modern times would confer performance benefits. It makes sense that our bodies would conserve energy and streamline energy pathways, and that taking advantage of these physiological truths will give us enough of a racing edge without compromising our health – since we’re training “with” our physiology, rather than in direct opposition to it.

There’s been limited modern research on “train low, race high,” and it’s pretty compelling. One study found that athletes who trained twice a day on alternate days and thus had lower muscle glycogen during the second training session almost quadrupled their muscle endurance, while athletes who trained once a day on consecutive days barely doubled theirs by study’s end. Both groups of athletes performed the same amount of volume and intensity, but only one group went into every other training session with depleted glycogen – and that group saw the greatest benefits to both work capacity and energy efficiency (glycogen and fat).

During your training, keep carbs right around 150 grams per day. That may sound like a lot, especially if you’re coming from the lower end of the carb continuum, but rest assured that 150 grams of carbs is a paltry amount for most endurance athletes. At the height of my training, I was blasting through upwards of 700 grams each day. As I mentioned yesterday, increase your carbs the day before – and morning of – your interval training, because much of the benefit from intervals comes from glycogen depletion, and you gotta have glycogen in your muscles before you deplete it. But for the most part, keep carbs at a moderate (for Primal folks) to low level. Stick to approved Primal sources, of course:

And remember: you’re training. Your performance during a particular run on a particular training day might not go great, but you’re in this for the long haul. You’re in this for the race day boost. It’s not a competition. You’re not trying to beat the other guy (because there is no other guy), you’re trying to train your mitochondria and your energy utilization pathways so that when the time comes, when the event rolls around, you are fully prepared to give it your best showing. Keep it in perspective and don’t beat yourself up too much. One final thought on training: it’s always better to start your race slightly undertrained than over-trained.

Couple Days Before the Race

Start eating more carbs. This is the classic carbo-load, and no, it doesn’t have to reach Phelpsian levels of mayo-and-egg sandwiches on white bread, kilos of pasta, and flagons of cheese grits. You can easily stick to starchy roots, tubers, and fruit (and even rice) to pack those muscles full of glycogen. Maintain your protein intake and moderate your fat intake. You’re looking to maximize muscle glycogen stores.

Just eat twice the amount of carbs you’ve been eating. So, instead of one sweet potato with dinner, have one with lunch and one with dinner. Eat the whole banana instead of half the banana. Aim for about 350 grams of carbs per day. And don’t do any hard training during these last two or three taper days. Maybe some light jogging or walking.

Race Day

If you have two hours before the gun goes off, eat a light breakfast with some representation from all macronutrients. Maybe a few eggs and a banana, maybe half a yam. Nothing that sits heavy in the stomach, and make sure it’s something you can digest. If you are a coffee drinker, a cup today will help mobilize fatty acids. Don’t go zesty, don’t experiment with something new. Stick to the tried and true. If you didn’t spend the last couple of days fueling up, the most optimal race day breakfast isn’t gonna save you. Sorry to say it.

During the race, maintain your composure. Your glycogen-replete body is going to feel eminently powerful. Try not to go too fast too soon. Better to start a bit slower, get those fats into the muscle cells and then increase the pace a bit later. As for mid-race fueling, I’d forgo the usual Gatorade offerings on the course and stick to the rocket fuel found in pure glucose. Some companies sell straight glucose polymer powders (complex carbs as maltodextrin) you can mix with water to your own desired consistency and carry with you on a fuel belt. This is the one time in your life that straight glucose is your friend. The method I have recommended for 20 years is to start refueling at about an hour in to the event, taking 20 grams of glucose every 20-30 minutes. This puts enough glucose into the bloodstream to help fuel muscles without interfering with the intended fat combustion – and it “unburdens” the muscles from having to give up too much glycogen too soon. Be sure to drink enough pure water (usually offered on the course, so you don’t have to carry that) as well.

Now, if you are so inclined, you can also make your own version of a sport drink/energy gel hybrid. It may not be astoundingly delicious, but it’ll get the job done. Here’s how to do it:

  1. Slightly heat some coconut water on the stove. Don’t let it get anywhere near simmering. Just let it get warm enough to melt the next three ingredients easily.
  2. Add a few dashes of sea salt, preferably one with high mineral content. Sea salt provides sodium, an important electrolyte, plus trace minerals. You’re going to be burning through a lot of it during the race.
  3. Add honey, preferably raw and from a local farm (remember, many store bought honey isn’t actually honey anymore).
  4. Add blackstrap molasses. Blackstrap molasses comes after the third boiling of sugar cane. It contains less sugar than either white sugar, brown sugar, regular molasses, or dark molasses, but far more minerals and electrolytes. See, sugar cane is a plant with roots that stretch deep into the soil to extract nutrients (some research suggests sugar cane roots may go down as far as six meters). Very few of those nutrients make it into white or brown sugar, and regular and dark molasses contain some, but it’s blackstrap molasses which gets the bulk of the minerals. So, when you add just a couple tablespoons of blackstrap molasses to your energy drink, you’re getting more than twice the potassium than a banana, more calcium than a cup of raw spinach, and almost 100 mg of magnesium.
  5. Mix it all together until everything melts and it’s a dark brown murky viscous fluid. I didn’t include specific amounts, but start with a couple tablespoons of each sweetener and the juice from one coconut (or one carton of coconut water). You’ll be cruising for the first bit of the race, thanks to your effective pre-race training and fueling, but when you really start dipping into your glycogen stores, having a banana or two and a bottle of high-potency Primal energy drink will prove useful.

Good luck. If you train and fuel smartly, you won’t really need any luck at all, but I figure it’s a nice thing to say regardless.

Once you’re done with the marathon, I’d move on to different things. Try rock climbing. Try mountain trekking. Heck, try an ultra marathon, but do it at an even easier, fat-oxidizing pace. But many of you will not. Many will get the endurance bug, and it’s a nasty one. This method of training and fueling is not a cure for the bug, but it will negate some of the worst symptoms. If you do try my training and fueling recommendations, let me know how you do. I’m especially interested in knowing how they compare to performances using other methods.

Take care, and be sure to leave a comment! Thanks for reading.

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Cant to wait to run mine!
    This is so helpful, really appreciate it Mark

    Steffo wrote on December 7th, 2011
  2. I recently read Ultra Marathon Man by Dean Karnazes and God love the guy but he definitely isn’t primal. It’s a great book though. Nice recipe at the end as an alternative to those gooey carb gel packs put out by Gatorade.

    Justin wrote on December 7th, 2011
  3. My favorite marathon story concerning gels was a few years back when I was in the Chicago Marathon. This guy had so many gels in his Race Ready Shorts that his crack was actually showing. I was laughing so hard, as were others, that I had to speed up to pass the guy.

    To this day I still wonder how low his shorts got before he event noticed.

    So for those who Mark’s hybrid gel – take note, figure out what container works best for you; and take only what’s necessary. Otherwise YOUR crack will crack others up.

    Jeff Pickett wrote on December 7th, 2011
  4. Ha, I have a whole bag full of Gu and Honey Stingers for anyone who wants them! I prefer sweet potatoes these days…

    Abel James wrote on December 7th, 2011
    • Haha, after I went Primal I found myself doing the same thing with my leftover non-primal foods. “Anybody want this??”

      Becca wrote on December 7th, 2011
      • Totally. I feel wrong even giving that stuff away! I wouldn’t want to unleash the gylcemic assault on my friends and family…

        Abel James wrote on December 8th, 2011
    • I’d take them – I’m transitioning and still use them :-)
      Is there a place I can email you?!

      AlyieCat wrote on December 9th, 2011
  5. You can get more carbs while running with a glucose/fructose mix, compared to pure glucose:

    I find that pure glucose (e.g. hammer gels) is a bit easier to digest than glucose/fructose mix though (e.g. GU, Power gels).

    Daniel wrote on December 7th, 2011
  6. Reading these past 2 articles have inspired me want to run a marathon now! Thanks a lot. Bookmarking this until summer.

    Joe wrote on December 7th, 2011
    • inspired me to run*

      Joe wrote on December 7th, 2011
  7. This is great for people who want a pro experience from someone who has done this type of thing professionally.

    Paul Alexander wrote on December 7th, 2011
    • There are no words to describe how bdoaicous this is.

      Giggles wrote on February 15th, 2012
  8. I just don’t think I will ever run a marathon in my life. But, you never freaking know until life is over. Maybe I’ll walk a marathon…

    Mark… I want to see 2 posts on dominating 5k’s and 10k’s!

    Primal Toad wrote on December 7th, 2011
    • I’ve walked the LA Marathon before. AND..I finished before a lot of “runners”. It did take me 6hrs and 30 min but it was a blast! Now I do a lot of 1/2 marathons, walking of course! You should give it a try! :) Just did Vegas 1/2 this past wknd!

      Kristie wrote on December 7th, 2011
      • I may actually do this. Or, why not do a 30 second sprint per every mile of wallking? Maybe every 2 miles? This sounds fun!

        Primal Toad wrote on December 7th, 2011
      • I’m training to walk a marathon in April! I’m really excited!

        Kristie, is it hard to find half marathons that don’t have a time limit faster than you can walk?

        Ellie wrote on December 7th, 2011
        • Sometimes a race will have a special early start for walkers. Something to look into.

          AlyieCat wrote on December 9th, 2011
  9. This is something I have been wondering about for a while. I hate running long distances and would give it up in a heartbeat. Unfortunately, being in the military does not allow for it. I’m not really in charge of my own workout regimen. Knowing how to refuel in a primal-approved method will help curb the random carb cravings I get. I’m probably keeping the donut stick industry alive single-handedly.

    Benn wrote on December 7th, 2011
    • Check out Jeff Galloway’s program. That’s exactly how he trains. Its called the run walk program.

      Jason wrote on May 8th, 2013
  10. no marathons for me, but it’s cool that you’re supporting those that are into it.

    one minor quibble. no way can anyone pack in 400grams of glycogen. 70 in the liver, and then 200-250 in the muscles, tops.

    jakey wrote on December 7th, 2011
    • That was my question too.

      annierobic wrote on December 7th, 2011
    • My understanding is that muscles can store ~350 g. glycogen and the liver ~90 g., dependent of course upon size of the person. That would mean a max of 400+ g. glycogen is indeed possible.

      Finnegans Wake wrote on December 8th, 2011
  11. I don’t run marathons, but I really enjoy training for and participating in longer trail races (about 15 miles). For the past year I have been following a similar nutrition plan and I am amazed at the improvement in my race performance! I am faster than I have ever been and I feel great during and after races. Coconut water and almond butter mixed with honey have replaced Gatorade and GU and I haven’t had any of my usual problems with dehydration and bonking during a race. Thank you for all the tips, I’m going to implement them immediately!

    Eddie wrote on December 7th, 2011
    • do you mix the coconut water with the almond butter and honey?

      gordie wrote on May 28th, 2014
  12. While local farm honey is obviously best, the “supermarket honey isn’t honey” theory may not be a lot of hysteria over nothing:

    Jeremy wrote on December 7th, 2011
  13. I swear by coconut water, especially on hot days, and I’ve traded in commercial energy bars for dates (pitted) stuffed with coconut oil–just a couple keep me during on long bike rides and heavy weight sessions.

    Nicky wrote on December 7th, 2011
    • This is a great idea, and convenient to carry! Thanks.

      Sabrina wrote on December 7th, 2011
    • you just blew my mind

      Marteen wrote on December 7th, 2011
  14. If I ever run a marathon I will use this great advice.

    Alex wrote on December 7th, 2011
  15. So just to clarify…Are you saying that is it best to run every day or every other.

    You referenced a study but it wasn’t clear as to which group performed better.

    Rebecca wrote on December 7th, 2011
    • I’m pretty sure he meant 2x per day every other day did better.

      Kate wrote on December 7th, 2011
  16. Interesting info for training for a marathon distance! I used similar nutritional support for half ironmans. Like you suggested, I have been looking into the ultradistance activities lately. Could you comment on how you would change a “training schedule” (in quotations because I prefer to just get outside and enjoy, rather than train) as well as nutrition – if at all. Thanks!

    Karen wrote on December 7th, 2011
  17. I fueled all of my long runs and race day with dates. They sat really well in my stomach and I never hit the wall at all during the last hour of the race, in fact I think my pace picked up a bit. I also did lots of sweet potato fueling the days leading up- 2 per day. Great recommendations, I’m studying exercise science in school right now and all of this is spot on with my course work.

    katie wrote on December 7th, 2011
  18. Great info Mark! I’m wondering if you would advise the same training and eating strategies for running a half marathon as well?

    Karen wrote on December 7th, 2011
  19. What about coconut nectar instead of the molasses? Does it have the electrolytes? I just happen to have some sitting around I bought on a coconut crazed whim…

    Marteen wrote on December 7th, 2011
  20. I make my own paleo nutrition for marathons and ironman and its great! way better than the crap on the course. I carry it in my sports bra. :) I use sweet potato (gluc), egg whites (prot), maple syrup (gluc), coconut water (K), sea salt (Na), coffee for a kick in the butt at mile 17.

    I think its silly to eat so clean to prepare for an even and then eat crap at the actual event. just seems stupid and i believe its very unnecessary. Further, I think that we train for events and then use the events to train for life. So… there is really no reason to ever eat crap.

    Ran my fastest marathon ever first time i started doing this.

    Crystal wrote on December 7th, 2011
    • This sounds awesome – would you mind giving me quantities – am hopeless working it out myself and would love to try it in training (up-coming Ironman race….)

      Shannon wrote on December 7th, 2011
    • Sounds great! Can you please provide your recipe and how you combine the ingredients? What do you use to carry with you? Thanks in advance! :-)

      Kelly wrote on December 8th, 2011
    • “Ran my fastest marathon ever first time i started doing this.

      Might be true, but correlation is not causation. Training and better fitness, not diet, likely resulted in the faster time.

      AlyieCat wrote on December 9th, 2011
    • what are the quantities?

      gordie wrote on May 28th, 2014
  21. This was incredibly effective for me. Trained for marathon living the standard paleo life. (Admittedly, I thought I was going to die on my 20 mile run — all I did was add 50 grams of sugar for the run (not enough!!!)). But, come game day, a nice sugary shot of gatorade every 1.5 miles, and I felt like a King at mile 23.

    Alex wrote on December 7th, 2011
  22. Thanks, Mark! Since going primal in August 2009, I’d been struggling with how to fuel the timed century bike ride I like to do once a year. I wanted to say “see you later, Gatorade,” so before my last big ride I mixed up a 1,000 calorie carb bomb consisting of 1/2 cup raw honey, 1/2 cup glucose syrup and enough unsweetened 100% cherry, blueberry, acai berry juice (Trader Joe’s) to top up a large water bottle. Along with two bananas, an orange and plenty of water, this got me through the 111 mile ride with energy to spare. My pre-race breakfast was eggs, sweet potato, banana and coffee. I also added carbs two days before (sweet potatoes and white rice). I had my best time ever, including from years earlier (pre-paleo). I’ll definitely try the coconut water, honey and molasses formula also.

    Speedhound wrote on December 7th, 2011
  23. How timely! Thanks!

    I just started racing again, half marathons mostly, with a full marathon in a few months. I’ve been doing just what you described: fasted training (though this is not new for me) and around 125-175 grams of carb a day. I am PRing this way… Race day carbs do wonders when you aren’t used to running on them! Coconut water is amazing.

    Question: since the half marathon is about 90 minutes, do you recommend re-fueling on the course any earlier (or still just keeping it to an hour in?) I’m normally not a fueler while running, but a couple races ago I noticed around 8 miles that I might really like a Gu….

    Catt wrote on December 7th, 2011
  24. This is a great article! I tried finding information on Paleo/marathon training and didn’t find anything so this is really great information! I ran CIM Marathon 3 days ago and had trained with depleted glycogen stores and while following a Paleo diet of mainly bananas eggs and sweet potatoes and found that to work just fine for training. I switched my nutrition the before the marathon and I followed the traditional pasta/gatorade/GU race plan and didn’t have a good experience with it so I’m excited to try this plan out later this year! I have to say it is a bit of a kick in the stomach to see the article 3 days after the bad experience!!!

    Jessica wrote on December 7th, 2011
  25. Good advice in this post according to my experience. I ran my last marathon a year and a half ago and had cut my intake of carbohydrates by roughly 75%, compared to previous years, during the months of training before the race. I ran the race (the fourth marathon of the Netherlands in terms of participation I think)5 minutes above my PR, but:

    – It was a sudden hot day (even the Africans under performed)after months of snow and freezing winds. The sudden heath didn’t bother me much, while in previous races high temperatures were the main limiting factor. Actually the race was cut short for the back pack of the participants, as too many people collapsed from overheating.
    – I ran a negative split. Never did that before in a marathon.
    – I placed 3th in my age group. Never did that well before in a major event.

    In training I did just about all training on rather low glycogen stores, including the interval sessions. I would do them slower or less of it, if it felt uncomfortable to sustain. I think doing intervals on low glycogen develops the ability to use fat at higher intensities. Once the fat burning system is well developed in low level activity – in my case hours of easy, relaxed running on the sunday mornings, enjoying the feel of unity with nature – coupled to a primal/paleo way of feeding. It compromises the development of a higher VO2-max but that is of less importance for a marathoner and can easily regained.

    go wrote on December 8th, 2011
  26. I ran a 100% primally fueled marathon last year.

    Dinner the night before was a steak and a lot of sweet potatoes.

    Breakfast was eggs with sausage and a banana.

    On the course, I drank my own chia fresca/iskiate. I used about a cup of coconut water to two tablespoons of chia seeds, the juice of 1 lime, a pinch of salt, and honey to taste. Since my wife had just finished nursing, we had lots of breast milk bags around and I carried it in those. I consumed two of these over the course of the race, plus water on the course and a couple Larabars. No gatorade, no gels.

    Whiteknight wrote on December 8th, 2011
  27. I’ve run an ultra marathon (50 mile) using the packets of but still needed complex carbs to get through it. Remember your water if you want to use these…..

    Dave wrote on December 8th, 2011
  28. And how would we change things if say we were training to qualify for the world championships of road cycling?

    Jordan wrote on December 8th, 2011
  29. I’m sure I’m the only one to do this, but about an hour before racing I used to down a bar of about 75-80% dark chocolate. Caffeine + a little fat + a little sugar kept me going a lot longer than most other foods I tried. (Clearly it’s not good training food on a daily basis.) The benefit to me was less bulk in my stomach… I found I couldn’t deal with sweet potatoes, rice, or bananas (or the like) before going out to race long. (I did this for 10k’s, 1/2’s, and the two marathons I ran back in the day.)

    Celia wrote on December 8th, 2011
    • Oops… Sure I’m *not* the only one to ever do that.

      Celia wrote on December 8th, 2011
  30. I ran my second half marathon this year, and succeeded in including my time from last year by almost a minute and a half and averaging 7:30 per mile over the course.

    I had been following paleo/primal with dairy for almost three months leading up to that, but had been moving towards adherence for months before that.

    A fair number of my runs during the summer had been first thing in the morning – about a six to eight hour fast before running.

    My race week fueling included more sweet potatoes added to my normal diet.

    I also cut my total mileage in training compared to last year – completing 140 miles between August and race day versus 210 last year. While there are intangibles like better form that probably contributed to my improved time, I’m sure in retrospect that diet, fasting and rest contributed as well.

    Dennis Murray wrote on December 8th, 2011
    • Dennis,

      I am 5 weeks away from my first half-marathon and I, like you, do my training first thing in the morning on a 12 hour fast. It is working great so far. Did you find that at any point during your training that you needed to fuel yourself before your long runs? Like say before your 11 mile training run? Friends keep telling me that I “need to eat something before my long runs or I will hurt myself, blah blah blah”. Your thoughts? Have you any advice for a first time half-marathon runner who secretly hates running?

      Melissa wrote on August 30th, 2012
  31. This post is so “quintessentially Mark” – I could hear your voice as I read it. :)

    I fuelled my marathon with almonds and dried beef. I ate a whole bag of potato chips at the end. I wish I’d had this article back in early 2010!

    Next time?

    gilliebean wrote on December 8th, 2011
  32. Can’t say I’ve ever had the desire to run a marathon :p

    Drama wrote on December 8th, 2011
  33. Nutrition tips for those who are training in brazilian jiu jitsu or mma?
    I eat “Paleo” from 8 months and my carbohydrates per day are 80/90gr, but often, during the training, I feel without energy..

    Thank you

    Dave wrote on December 10th, 2011
  34. A big question about fueling before the race that’s bugging me:

    I don’t eat the morning of the race — never want to. Just the night before. Instead, I’ve been consuming some glucose in liquid or some coconut water (with electrolytes and amino acids) about 15 minutes before the start. But does this interfere with my fat burning mechanism for fuel? Is it better to start the race fasted and add the sugars after a few miles? Or should am I doing the right thing by getting sugar in me before I begin running?

    I do half marathons, btw…

    Catt wrote on January 4th, 2012
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    alucia wrote on March 13th, 2012

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