How to Train for a Marathon

Leading into this post, I promised myself that I wouldn’t try to dissuade people from running marathon(s) or any long distance races. I already do that plenty in other posts, so today’s is geared toward the folks that simply are going to run a marathon or marathons, regardless of what I say. I know these people exist because I used to be one. Running a marathon can be a huge bucket-list accomplishment. With that in mind, when people write in to ask me about training for a marathon, I think about what I would do in that situation knowing what I know now. How would I train to do the least damage and get the most benefit? Truth is, if I put my mind to it, and you had elite level potential, I could most likely train some of you to win the thing outright, but that’s not what this post is about. This post is about finishing the race without embarrassing and/or hurting yourself. It’s about accomplishing something big, something special. It’s about training for a decent, respectable showing in a marathon. One (or two, or three if you must) and done.

To be an effective marathoner – or even to just finish one – you have to be an effective fat burner. It is the beta-oxidation of fat, both dietary and stored body fat, that provides much of the aerobic energy you will need to maintain reasonable pace for 26.2 miles. I mean, 26.2 miles is a whole lot of miles. When you’re driving somewhere and the sign says “26 miles” to your destination, you think “That’s kinda close, but kinda far.” Now picture that on foot. Yeah. Good luck doing that as a fully dependent sugar-burner. Fat’s the ticket, and if you have spent the requisite few weeks reprogramming your body to derive most of your energy from fat while at rest and at low level of activity (through your PB diet), you will be primed to access fat while training.

With that in mind, you’re not really training for a marathon, per se – you’re training your body to become more efficient with its energy so that you can run a marathon. You’re actually reapportioning how your body uses various types of fuel at different activity levels. Thus, training for a marathon comes down to three primary goals:

1. Achieve mitochondrial biogenesis and optimality.

Increasing the number of mitochondria (biogenesis) will spread the aerobic workload – the beta oxidation of fats and some glucose/glycogen– across more cellular power plants. Improving the number and efficiency of your mitochondria will allow you to do more output (running) with less reliance on glucose and/or glycogen as a primary fuel and more reliance on fat (input). In effect, this will increase your “miles per gallon.” Only instead of filling the tank with gasoline, you’re using stored body fat.

2. Increase the amount of fat burnt relative to carbs at a given work output.

Glycogen depletion is the defining point of “hitting the wall,” so you want to avoid the wall as long as you can. Remember, it’s 26.2 miles. The more fat you’re able to burn and turn into useable energy, the less glycogen you’ll go through. Muscle glycogen storage is very limited, and whether you’re a sugar-burner or a fat-burner, you’re still going to store the same amount of glycogen – it’s the rate at which you deplete it that counts. If you can access fat more efficiently and use fat for work that would normally require glycogen, you’re winning. If you can train to use fat for higher workloads, you can increase or maintain the intensity without dipping too deeply into your muscle glycogen.

3. Increase your aerobic threshold.

The aerobic threshold is the maximum level of output at which you are still relying primarily on the aerobic, or oxidative, energy pathways. As long as you stay under that aerobic threshold, you can train yourself primarily using fat to generate ATP energy (and your high fat diet plays a key role here, too). Once you cross that threshold you start burning more sugar. As you get further into anaerobic territory, however, you’re burning mostly sugar – liver and muscle glycogen. Sugar burns faster (and hotter), and it doesn’t last nearly as long as fat. So if you can increase your aerobic threshold, you should be able to increase the intensity of your runs without dipping too deeply into your glycogen stores. Ideally, then, a prospective marathoner will train to increase his or her aerobic threshold (we’ll save the ANaerobic threshold discussions for another day). That way, you can save the glycogen for the finish line, when it really matters.

One way to start out is to simply keep your heart rate at or below 65% of your max on longer runs (and this might eventually become 70-75% of max as your training benefits accumulate). To determine a person’s aerobic threshold, I find the most intuitive way is to have them run “long” (6-12 miles after a few weeks of sufficient low level training) runs on back-to-back days on fewer than 150 grams carbs per day. If you can complete both runs, both days, without adding back extra carbs, you’ll know you haven’t been dipping too deeply into your glycogen stores. If so, that’s your aerobic threshold pace. Remember it.

As for a specific training prescription, here’s what I’d do every week, beginning at least 12 weeks before the event and generalized for the widest possible audience:

1. Two to three slow aerobic threshold runs.

These should be easy runs performed just below or at your aerobic threshold at the type of pace you can easily maintain. If you are just starting out from little run training, these sessions can be long hikes with easy jogs thrown in. These are great opportunities to just log mileage and improve fat oxidation efficiency without too much stress, where you can actually think about stuff other than the run (hey, maybe even work through some personal issues). For improving mitochondrial efficiency and stimulating mitochondrial biogenesis, these aerobic threshold runs (and your Primal Blueprint eating strategy) will be your bread and butter – the kind of low-level training I referenced in the post on improving mitochondrial efficiency through exercise.

To really promote fat oxidation, limit your carbs or even go into these runs in a slightly fasted state. When you begin dipping into glycogen, or hitting the wall (which might come soon-ish since you’re fasted or slightly carb depleted), back off. You want to stay away from the anaerobic pathway. The length of these runs will depend on your baseline endurance, and you’ll soon be able to stay under the aerobic threshold for longer (which is the whole point!). I would add a mile each week to the longest of these runs.

2. One interval session, followed by an active recovery day.

Run intervals one day a week – alternating repeat 400 m one week, 800 m the next. Walk or jog for two minutes in between. For the 400s, start with as many as you can comfortably do the first week and add one each week until you are at 12 intervals for the workout; for the 800s, work your way up to 10. On a scale of 1-20 with 20 being the most intense, keep the intensity at about a 14-16. It’s not an all-out sprint, because, well, good luck sprinting 800 meters multiple times, but this is at faster than your intended marathon race pace for sure.  The next day, go for a walk or hike or go bike somewhere. Don’t go climb Half Dome or anything. Keep it pretty light.

For the intervals, you’ll definitely want to carb-load the day before. Slam the sweet potatoes and yams, about 400 carb grams worth, since you’ll purposely be blasting through your glycogen that next day.

3. One race-pace run.

Here, you’re trying to emulate the race pace without going the actual distance. It’s necessarily higher intensity than your regular runs, just at or slightly above your aerobic threshold. It’s going to be tougher, too, with some glycogen depletion. Don’t expect to pull out your iPhone and check Facebook in the middle of it.

Start with at least two or three miles, or a bit more than whatever length your threshold runs are, and add a mile each week (minimum).

If you plan on doing this barefoot or in minimalist running shoes, be absolutely certain your lower body is acclimated to it. A marathon is a long way for someone whose feet, calves, knees, and hips (with all the connective tissues that go along with said joints and body parts) have only been spending cursory time exercising without protective footwear. Review my post on making the barefoot transition and confirm that your ship is in shape.

Well, that’s what I’ve got. Remember, this is just general advice for the wider public. If you were my client, I’d tailor the training to you, but you’re not. For what it’s worth, this is how I’d train myself I were crazy enough to get back into running marathons, because it’s effective, it’s low-cost, and it’s actually a fairly healthy way to go about training for one.  I mean who doesn’t want rockstar mitochondria?

Any runners out there? Any marathoners? How do you train?

Next time, I’ll discuss how to fuel a marathon while staying Primal. And yes, it’s very possible.

Whew, and I didn’t even mention the phrase “Chronic Cardio” once. I’m pretty proud of myself. Thanks for reading.

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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124 thoughts on “How to Train for a Marathon”

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  1. This is so awesome! I used to run marathons before going primal but gave it up. I’ve always wanted to try it again as a supremely healthy person. Maybe I will do it once just for fun…

    1. Did you ever get to do it once just for fun?

      I’m about to begin training for a may marathon.

    1. I am interested in 5k training too. I like the idea of an all out relatively brief race that wouldn’t require much training outside of weekly intervals, and maybe one other day of running weekly. What second workout would offer the most benefit?

      Now in my 40’s, I would love to beat my old 5k times from years long gone.

    2. Yes! Would love a similar post on improving short distance runs and triathlons the primal way!!

    3. Yes! Running the Rugged Maniac next year and I’m weakest with running. I just don’t love it like I used to and actually loathe running now.


      This will prepare you for whatever distance you want to go with a fraction of time most spend during marathon training. I used it for a half marathon and did very well, felt strong the entire run and never ran more than 7 miles during training. It also has a program layout for triathletes.

      1. Trained for ironman using crossfit and crossfit endurance, no more than 12 hours a week. Knoced 35 minutes off previous bike split from ironman one year earlier.

    5. I’d be very interested to know how to rain for a 5k or 10k as well!

    6. I’ve been interested in that same thing as well. It’d be awesome to totally destroy a 10K race…

      1. I surprised everyone, including myself, in an 11k race last year. On reflection, it’s probably because I trained like this without being conscious of it. The distances were shorter of course – 3-5k runs several times a week, always in the morning on an empty stomach; sprints (100-200m)once or twice a week; and an 8-10k run now and again (as I tried to reassure myself that I could do the distance in my arbitrary goal time of 57min). On the day, having given in to temptation and eaten bananas and sugar that morning, I did it in 47min – not olympic fast but waaaay better than I had run while training.
        It’s puzzled me for ages why that happened but it makes sense now, thanks Mark.
        Oh yeah – I trained and raced in Jika Tabi and VFFs – switching from sneakers to minimal shoes erased my troubles with shin splints and effortlessly increased my running pace.

    7. I contend that training for peak performance in 5k or 10k is not much different than marathon training. Having an awesome aerobic base translates into success in shorter distance races such as 5k and 10k, which still place a tremendous premium on aerobic endurance. It’s difficult to absorb and benefit from high intensity training without a strong aerobic base anyway. Hence, the top middle distance runners in the world routinely hit 100 miles per week in training. Their workout particulars are different from an elite marathoner, but the big picture principles, such as those suggested in the post, are applicable even if your goal is a 17 minute or 36 minute effort.

  2. I’m not so sure the human body was ever meant to run for 26 miles in one go. On the other hand It’s fascinating to see just how far one can take the human body to see how far it can go. Excellent post.

    1. I’ve run a few marathons, but it is amazing how much better my body responds to sprints and/or much shorter races (5k/10k). I actually lost body fat (and built a bunch of muscle) when I stopped running 50 miles a week. Stopped getting sick, too.

      That said, running those distances is a huge mental rush and the sense of community in runners is something that can’t be adequately described. In short, marathons are great for the bucket list, but not a particularly healthy lifestyle choice. 🙂

    2. AS long as you don’t take it *too far*. There are way too many stories of people who appear to be otherwise healthy, and even young (20’s) dropping dead during marathons.

      I will not be doing any. 5K is my max. I’m sure I could do the 26 mile thing, I just ain’t gonna…

      1. “even young (20?s) dropping dead during marathons…”

        Including poor Pheidippides, who ran the orignal race from Marathon to Athens to announce victory before keeling over. [yes I had to look that up.]

        1. Which is 1 reason why I would never want to run one. I mean, the original marathon winner DIED! Now quick, which nation did the Athenians beat?

        2. oh guys, really …. he ran from Athens to Sparta to ask for help. The spartans refused, so he ran back to Athens (245km) to bring the bad news.
          Then they send him to Maratonas to tell the troops they had to do it alone … which they had already done. So without any rest he returned to Athens to announce the victory and drop dead after 245+245+42+42 = 574 km

          There is a race comemorathing this feat: the Spartahlon, which I hope to run one day … in a pure primal state of course!

      2. People drop dead everyday from a multitude of things. It was a problem with their body that caused the death – if the marathon, half marathon or yes, even 5k, hadnt have done it another activity would have sadly.

    3. Actually humans are the ultimate long distance species. We are faster than all other land living mammals on this planet when it comes to long distances. Search persistence hunting on Youtube and watch the amazing accomplish of hunting with help of only your legs and feet.

  3. Yeah, great post Mark. I’m bookmarking this for when it becomes applicable, because it will, it’s definitely on my list of things to be able to do.

  4. Mark, this is timely for us. We just completed the 12 week Stu Mittleman plan. I got to a 16 miler and then my primal health fell apart with colds etc. My wife has held her training (woman are tougher anyways haha). Her marathon is in March and we are ready to begin another 12 week cycle. How do you suggest we alter the plan?

  5. I ran the Marine Corps Marathon two years ago and made it through by consuming massive amounts of sugars and, sadly, caffeine. I did it in under 4 hours, so I was happy, but I’m sure I did massive amounts of damage to my body. Wish I knew then what I know now…

  6. I was just thinking about getting into running again. I have a couple half marathons under my belt but have never checked the full marathon off my bucket list. Think this will be a great approach if I decide to go for it next summer.

  7. I have run the London marathon once I found it fun and relatively easy. (1999)

    Doing it primal and barefoot would be awesome.

    Don’t run much these days though.

    Great post.

  8. I ran a marathon this past spring for the first time and trained successfully although I wasn’t really fully primal. But most of my carbs came from sweet potatoes, I a big one almost every day. And bananas those were a staple. Looking forward to seeing your fueling portion of this. Although I’m not running much anymore its interesting to read about.

  9. Interesting post. I actually experimented with some of these techniques about 6 months ago when I ran a marathon up in Vancouver in a relatively-untrained state. I didn’t actually do any marathon preparation because I decided to run it just a few days prior, but most of my CrossFit and strength training adhered to some of these principles and I came out of it okay (3 hours 49 minutes, no injuries).

    One other thing that I thought about was how doing some light interval work in VFFs could address the durability component of low-volume marathon training. My argument, which is based entirely on anecdotal experience, is that running short distances in bare feet/VFFs would help build up better durability for longer distances, but help you keep your training as parsimonious as possible.

    Anyway, if anyone is interested in reading my experience with a (relatively) untrained marathon, I posted a report on it here:

  10. When I was running marathons (whether my one official road race or informal marathon distances on the trails), I was eating way too many carbs, and using sugary energy drinks, and wearing relatively clunky shoes (“lightweight trainers” that to me are like boots now and donated away). I don’t expect to do another marathon soon, but I do wonder how I’d go about it a healthier way.

  11. Looking forward to the fueling post. Looking for my excuse to carry coconuts and a machete on the course.

  12. I’m actually training for a barefoot half marathon, but I was just kicked out of my gym for lack of shoes.

  13. I am a Paleo ultra-runner, and I can assure you there are lots of us out there. I train pretty much exactly as you’ve laid it out, except I do back to back long runs on weekends. I train low carb and race high carb.
    I start my long run in a fasted state, usually just coffee and cream for breakfast, then run.The only time I use gels is when I race, or a training run of over 2 hours, and even then, nothing until the two hour mark.
    Something interesting, my blood sugar in the morning is fairly high even when fasting.

    1. We should start a group for paleo ultra runners! I’m not 100% paleo but probably 80-90% there. 🙂

      1. I’d be up for that. Doing a 50km Trail Run in the Spring and really have no desire to going back to logging huge miles and eating crap.

    2. @Digger, I’ve measured relatively high glucose on a long run in a fasted state. I believe this is a result of gluconeogenesis (getting glucose from the protein in your muscles/liver). So my question is, if you starve your body of glucose and it’s gonna make it anyway, why not give your body what it needs for fuel in a more efficient manner like eating carbs, and have better muscle recovery to boot?

      1. Hi;
        I do eat good carbs, just no processed foods,no rice, no sugar,potatoes or pasta. I consume more fast acting carbs(gels) while racing or on long training runs.
        I also have a beer or two after a good run.

      1. Thanks, I just had it tested a couple of months ago. I believe I am experiencing the “Dawn Effect” for some reason. My liver is producing glycogen during the night. We have diabetes in the family, but so far so good for me.

  14. Going from couch to primal to half iron man (70.3)from last october to this next october. Working on being fully primal right now to lose some pounds (some=forty) And I was going to do some light training this winter and sprint triathalons in the spring and then begin the major training in march…I’m just nervous I’m going to hurt myself…I know I want to do it(and I promised my Paleo sister)but I guess I would just like some advice on how to begin and the easiest ways NOT to hurt myself. Any ideas?

  15. Mark: I agree with your training strategy very strongly. I have rationalized my ultra running to be part of a Primal stragety since trail ultra are typically over rougher terrain where your pace is varied and is dictated by that rough terrain. In most of the 30-40 mile runs I’ve done, a “good” pace is 12-13 minute miles, with lots of hiking. That is much easier on your body than even a 8:40 marathon! I’d did well (top 3rd)in maybe 5 50k’s and two 40-milers only maybe 30-35 miles a week: 1 track day with 400’s and 800’s exactly like yuour plan; 1 “tempo” day of 5-8 miles at 7:45 or 8:00 pace on hills; and my “long” run of 13-20+ miles with lots of hiking. Cross-fit or other “lift heavy things” workouts will get you through the long miles more than you could imagine!

  16. Oh, as far as fueling, I find that now that I’m more of a fat-burner, I won’t eat anything of runs less than 2-3 hours, but on longer runs and during the “event” (I don’t call it a “race”) I’ll use coconut oil and honey mixed in a gel flask. On cold days the coconut oil can get a little stiff, but it goes down easy and provides very steady energy. No bonk and quick recovery.

  17. One half marathon was a bucket achievement for me. I’m glad I did it. The group I trained with (SacFit) takes a fairly primal approach, at least to training.

    I was going to continue training but the group brought a speaker named Mark Sisson. That was the end of distance events for me. (Thanks Mark!)

  18. I did a couple of marathons in the last 2 years. No real problems with endurance etc., but it simply murders my joints. I’m not up to the three months recovery again this year.

  19. My first and only marathon my goal was just to finish. I found Jeff Galloway’s run/walk program. Have you ever looked in to that Mark? I think that is probably as close to primal marathon training as one could get. Especially the beginner program.

  20. I’m a primal ultra runner, I have changed my training to something very similar to what you described above. I am using the Maffetone method, I changed my diet and training back in august 2011. I have never felt better in both training and racing with PR’s in half marathon, marathon, 50k, and 50 mile distance. all of this in the past 4 months. I have not gotten sick, or injured, despite all of my staff at work, and friends being sick multiple times.

    1. That is similar to my story. Despite running for over 20 years, I have set PB’s in every distance from 10k to 50 miles since going paleo. This is all at 50+ years old!

  21. 400 grams of carbs from sweet potatoes to carb load? Thats 2kg of sweet potatoes…thats diarrhea!?

    1. No it’s not. I just sprinted and ate 720 grams of sweet potato for my 150 grams of carbs. I’ve eaten that much before and it did not cause any problems. It sounds like a lot, but they are dense. It was only a typical bowl about 4/5 full after I mashed them.

      1. Yes it is.

        100g of sweet potatoe contains about 22g grams of carbs

        so we are looking at around 1800g of sweet potato to carb load 400g of carbs
        you actually ate 720 grams in one sitting?

        Can mark recomend anything for people whose guts don’t appreciate more than 100g of sweet potato / squash at once?

  22. what incredibly good timing. I was just looking into marathons yesterday morning. Thanks Mark

  23. Hey Mark, what would the equivalent to a marathon in terms of bicycling? A century (100 miles) or more? I’m not sure I could run a marathon (nor would I want to!) but I do enjoy doing a century every few months. Not for speed, but just to finish (and yeah for the sweet treat and/or beer often provided at the end).

    I’ve done a flat, cool weather metric (100 K/66 miles) on about one 1/4 my usual of the provided bagels and peanut butter and felt great, but on a hot, hilly century, I would get nervous about bonking and think I ought to be eating all those carby snacks at the rest stops.

    In a nutshell, does the above advice also apply to training for cycling and will the upcoming fueling advice apply as well?

    1. Very much doubt a century is the equivalent of a marathon but it is still a grueling thing to do.

      I used to plan on consuming 1600 calories of glucose during the ride through high caloric energy drinks.

    2. Your comment intrigued me as I finished up my Ironman training (i.e. lots of long bike rides) before I tried paleo. Too scared of bonking without my gatorade, pickle juice, and pb sandwiches.

      I’ve also bookmarked this website though I haven’t spent much time on it. It’s written by a dedicated cyclist, paleo follower who has a background in nutrition. I actually found it on MDA a while back.

    3. My last marathon was 30 years ago, and I agree a flat century is not as tough unless you are going for around four hours. On the other hand, a century with 10,000 feet of climbing is a little worse if you are keeping the speed up (I’ve done that ride eight years in a row now.)

      I’m just starting to train for my third “Devil Mountain Double” (200 miles 20,000′) and I was just trying to decide how to structure it. I think this is a perfect starting point. I was going to lean towards a little more interval work (I’m ancient you know.)

      The thing that I really need to figure out is how to eat during the event.

    4. I think the “equivalent” depends on several things. What kind of bike are you riding? (I just did a century on a mountain bike with knobby tires. Took me about 7:30 on a very windy day. I don’t have a TT bike, but if I did I assume I could have cut at least an hour off of that). Are you riding alone or in a pace line? Terrain? Weather? (Wind was over 25 mph in the one I just did).

      And are you focused on the energy system or are you including stress on joints? For most people I think a marathon is way harder on joints than a 100 mile road ride.

  24. Great post! I know a lot of the experts frown upon doing chronic cardio or steady-state work, but it’s what you’ve got to do if you’re running long distances. I’m following Hal Higdon’s 1/2 plan and running 1 long slow run, 1 race pace run, 1 recovery pace run, and 1 day of intervals; pretty similar to your suggestions. I’d love to see more information on fueling, I’ve been sipping Gatorade on the long runs.

  25. I think fuel partitioning is based more on our activity level (easy v. hard), and less on what we eat. It doesn’t matter if we starve our bodies of carbohydrates, it will still produce the glucose that it needs for fuel from proteins from our muscles. It’s an inefficient process, so why not just give the body what it needs for fuel for optimal performance and sufficient muscle recovery?

  26. My husband and I recently ran the Marine Corps Marathon and trained with main site crossfit alone, but adding/switching a sprint based WOD at least once a week. We both hit nearly 30min PRs, felt great throughout the entire race without hitting any walls, and recovered quickly. We think this speaks volumes about the advantages and diversity of short duration high intensity training. We have also been primal/paleo in our dietary lifestyle since January 2011, fueled the week before by adding extra fruit and some sweet potatoes, and ate good steaks, brussel sprouts and sweet potatoes the night before race day. It was an amazing experience and it really confirmed our faith in our primal lifestyle, especially considering the cardio-overload training of our past that left us with slower times, walls during the race, and painful recoveries.

  27. It’s all good stuff but in what about runningpose and technique? I’m all into ultrarunning at the moment with a 50 mile race coming up in may. Since shifting to vibrams on shorter distanses my pose has changed to the better and the pain in hips and knees after loong runs aren’t as bad as it used to be. However the weather in Sweden this time of the year gives no pleasure running, so I will make my body stronger with CrossFit, TRX, Kettlebell, Primal walks and very long distance crosscountry skiing. I’m sure this kind of diversity will pay off when the ice melts away. This is a

  28. ..really good place to hang out by the way. Thanks for all the inspiration and info! 🙂

      1. Paul,

        Thats funny, I ordered the book: Born to run, the other day looking forward reading it even more now.

        Thanks for the link, great article and even though I’m already sold to the whole barefootrunning idea I haven’t heard of the 100 up exercise. I will try it out for sure!


  29. Hey I recently completed my first marathon! I trained by doing intervals once or twice a week. Anywhere from 100s up to mile repeats. Then on Sundays I would do a long run anywhere from 4 to 10 miles. I never went longer then this. I also had big ten marching band practice 4 days a week so at this volume I was already weary of recovering enough. I completed the marathon in 3:29 without spending countless hours of training and without a huge running background

    1. Oh and I forgot to mention, I run pose and own vibrams but I ran the marathon in more of a traditional running shoe as I felt that my lower legs weren’t ready yet. Prior to and post of the marathon I was a very active crossfitter

  30. I used to run, until I took up Judo, now there’s no need to run…….

  31. This is the exact type of training i had when i ran track and cross counrty in highschool and college(10yrs ago). i only ran cross to stay in shape for track. this kind of training allowed me to run sub 50sec 400’s and sub 2:00 800 early in the track season. i do believe this post is my new inspiration to start training again!

  32. This is so timely!! I normally do crossfit 3x/week, a hike with my dogs 1x/week, and then take the rest of the week off or just do long walks with my dogs. My mom recently asked if I wanted to do a half marathon with her in May. My initial reaction was “no way!”, who needs the ‘chronic cardio’? Then the more I thought about it the more I wanted to do it to prove that I could train for the run and complete it without going overboard on the cardio. Also, to complete it while staying totally Primal and not do any carbo-loading. My family and friends already think I’m weird for the way I eat and workout, so I’d really like to show them that I can do things my way and have a great outcome at a half marathon, which they consider to be an accomplishment to be able to finish. AND I fully intend to do the run in my Vibrams, which they also love to make fun of. I had been searching the internet on the very topic earlier today so this is perfect, Mark! Thanks so much!!!

  33. I’ve done 2 marathons – one before being primal and one after (trained CW and primal respectively) so I can offer some perspective. BTW I’m not a “natural” distance guy either – ran the 200m and 400m in high school – endurance was never my thing.

    Spent 6 months of 2003 training for a marathon for January of 2004. Full on CW person…grains, carbs for fuel, calculating calories, Asics boats for running shoes, you get the idea. Ran 5 to 6 days per week – energy gels and gatorade during long runs on the weekends (longest run in training was 22 miles)…like any typical marathon plan you might find in Runners World or most books.

    Race day…last 5 miles was miserable, felt horrible for about 2 weeks after with soreness and joint pain. Finished in 4:45.

    Started going primal before I knew it was called that in early 2005. I wanted to have a go at the inaugural Goofy’s Challenge at the Disney Marathon in January 2006 – called so b/c the half marathon was on Saturday and the full marathon was Sunday. Goofy’s Challenge was completing both that weekend.

    By the time I started getting serious about the race, I had several months of learning barefoot technique behind me. Trained in and did the races exclusively in the Puma H Street which Pose people may be familiar with.

    My weekly training consisted of 20 – 25 400m repeats as intense as possible (over 2 days, usually MW), occasionally I would run 10 long hill sprints up a seldom used (this is key 🙂 toll road exit ramp near my house one of those days instead of 400m repeats.

    On Saturdays I would alternate one week with a 2.5 hr walk/hike with very little (I mean around 20 mins tops) jogging and the other week with the same thing but 5 hrs to simulate having to do distance and then double the distance the following day for the race.

    For the race weekend I cruised the half faster than I wanted in 1:58, felt great and the next day did the 26.2 in 4:07 and felt even better – not to mention got 3 really cool medals. Fuel during running was exclusively coconut oil and deer jerky (best friend is avid deer hunter). No real soreness, no pain. In fact the next day after (Mon) was my first day at a new job and during orientation I was walking around all day up and down steps like it was just another day.

    Haven’t done a distance event of any kind since then – haven’t had the desire – guess I scratched that itch or something, but I guess my point is that Primal can be a viable (and superior) training strategy for distance events.

    1. What a wonderful training plan. It would never occur to me to walk my long runs. I have done long runs with walk/run but always very little walking. I have never see this recommended but its hard to argue that it worked for you!

  34. I have run a few half marathons. Will do one marathon at some point as a bucket list item.

    I just completed a Tough Mudder race. 12 miles.

    I’m actually a big believer in not really training at all. Work out the primal way, take lots of walks …play a lot and you will be in fine shape to run a half marathon…or perhaps even a full marathon. If you want competitve times, then yes by all means you must train, but other wise I don’t think it’s necessary. Running all the time break your body down. Putting a “stress’ on your body once in a blue moon is actually good for you I think. This is all speculation and self experimentation but it worrks for me and others I have talked too. I will say it again, I didn’t train at all for the Tough Mudder Race and at age 44 I had not problem running and doing all the obstacles.


  35. Another primal ultra runner here. Mark’s comments are pretty much spot on with my training. A great resource for this type of training is Phil Maffetone (google him). He has a more specific way of measuring aerobic threshold (called the 180 method) and through the use of a HR monitor makes training and improvement more measurable. He agrees with all of the footwear and nutrition items that Mark discusses as well. A great resource for all of the Primal Endurance athletes out there… and would be a good speaker at a Primal Gathering in the future.

  36. Marathons are so hard! I would never have the patience to train or run such a thing. I’m a sprint kinda of guy. That’s exciting!

  37. Didnt eat primal yet when I ran my first marathon but the biggest problem I and most other people seemed to have was getting the legs to move after ~30km. I would recommend a few 3h runs before the race just to get your body used to moving for longer than 2h periods.

  38. I ran 2 full marathons and 1 half marathon in a 30 day period this fall. A 3:42 full, a week later a 1:36 half and three weeks later a 3:43 full (trying to BQ to no avail, I think I was tired).
    I trained this summer running two days a week. One long run (tempoing every 2 miles) and one medium run. I ate as primally as possible and avoided as much sugar as possible.
    My recovery was ridiculously amazing, as protein is key in recovery.
    Of course I ate sweet potatoes, bananas, and definitely cookies (if I can’t eat cookies after running 20 miles, when can I?), but not too much.
    The key for me was nutrition, not over training (seriously, two days a week running most of the time and taking those runs at a close to race pace) and tempo runs (sometimes when I could get in a 3rd run). I have a 1.5 yr old and 2.5 yr old which is why my training was limited. That’s why I had to take every advantage I could, and nutrition was one definite way. I don’t think there is any other way to train for a marathon than by eating primally and keeping the running to a minimum.

    1. awesome!

      did you lift? I’m trying to keep lifting and train for a marathon.

      did you train 20 mile max long runs before the first full?

      how do you define tempo run? vs race pace ?

      thanks for any info you can supply

  39. Wow! What a great day for this post. My GF just asked me to run in a Marathon with her for Gasparilla (Tampa, Florida) it i in March and it gives me time to follow the lead. I have only once run in a 5K 25 years ago. This is just something on my list. Thanks for the Post.

  40. Mark, I’m with the others; we need a post on training for and dominating 5Ks!!

  41. I’m going to run a marathon soon, after having trained in five fingers fueled by sweet potatoes and not running more than 2 days a week – one all-out sprint and plyometrics day, and one mega-long run. I’ve always considered my long runs “play”. I run them slowly and enjoy the scenery. I’ve seen too much in the paleo/primal community hating on marathoners, but as you have detailed here, LONG DISTANCE RUNNING SHOULD BURN FAT. It doesn’t have to tap into glucose-burning and stress responses. Running 26.2 miles shouldn’t feel like Crossfitting for 3 hours straight.

    This post made me so happy 🙂

  42. Just ran my first marathon in November (wasn’t primal) but have recently been considering moving more toward primal eating. Can’t wait to read your fueling post.

  43. I just finished my sixth half marathon on Sunday after going primal for 40 days. I beat my last seattle half marathon PR by 10 minutes! I did however eat carbs for the three days prior to the race. I still wonder if my success was from the primal diet or the three days of carbs. I didn’t even train as hard this year! I pretty much only run twice a week due to injury and I supplement with other types of cardio, such as spin class.

  44. I’m with Kelly – if you don’t take carbs during a run of this length, you’re going to get the glucose you undoubtedly need from your muscle protein instead. Why waste away the muscle that you’ve been Lifting Heavy Things so hard for. The carbs won’t hurt you in that context, with your insulin sensititivy at the max. They go straight to the engine!

  45. Mark,

    Thanks for the tips! It’s good to look at it more as conditioning your body than training to run. I don’t run marathons, but I’m about to start preparing for a 15k, so I’ll definitely incorporate some of these suggestions.


  46. I ran a marathon a couple years ago for my bucket list and hated it. I love the half marathon distance though. The full is just not for me. I got sick during training and a couple weeks after the race and couldn’t kick it for a few weeks. Not worth it! Now if I run (which I still like even though I burned myself out on it w/ the marathon training) I keep the distance to less than four miles. Sometimes I miss the mental high of running longer but I haven’t gotten sick nearly as much since I cut back so I still keep it short. When I ran 40 miles a week I had much more trouble with weight gain and carb cravings. 20-25 miles per week seems like the optimal amount for me though now I walk a lot more. My joints in my feet are finally healing from all the damage I did to them years ago!

  47. I use Phil Maffetones 180 minus your age for your max heart rate for training runs

  48. I’m interested in how one can eat primal and run a marathon. I thought one needed alot of carbs to burn

  49. Great topic and so true!
    I too believe in Maffetone holistic method and find it very paleo/primal compatible. Actually it was his book that showed me importance of whole food diet and I switched to paleo thanks to it.
    This combination of low/moderate carb diet and low stress/no pain training helped me to improve my marathon time by 36 minutes in one year (from 4:01 to 3:25) and, importantly, improved my health.
    Now, I like running and love my weekend long runs, but I do it for the fun of it and at very easy pace – no chronic cardio and no need for carb loading.

  50. I don’t see what’s wrong with long distance running- we evolved to be hairless, bipedal and sweaty for a hunting tactic that resembles modern-day ultra-running.

  51. I am a primal triathlon coach and I find that it is VERY hard to convince people to let go of the sports nutrition. People are AFRAID to go without it and convinced they won’t survive if they aren’t constantly eating. We recently had a client switch to primal while training for a marathon and he lost 15 pounds and PRed.
    You can do a lot as a fat burner, and when you learn to do that it makes carbs feel like rocket fuel! Carbs are a great tool for when you need to go fast, but most people use them for every single workout when it’s not necessary.
    Most athletes I know maintain or gain weight when training for long events because the exercise makes you hungrier and because the carbs go through the roof. Plus they are too tired to cook! Training for a marathon is hard, not because of the mileage. It’s hard because of all those other reasons…makes you hungrier, makes you too tired to cook, makes it harder to maintain control of your diet.
    Lots and lots of endurance athletes train so that they can eat bad food. It’s very hard to convince athletes that exercising doesn’t “allow” them to eat junk. I wish more people would realize that running a marathon doesn’t make you a healthy person if you are doing it overweight and on a terrible diet.

  52. Okay, I know this is not the same thing at all, but I tried Zumba yesterday, and I think I’m addicted. Is there any way I can justify it and not admit that it’s chronic cardio? Do you think it could count as my all-out effort every 7 days?

    1. Had to google it, but that looks more like “play” than cardio.

  53. I’ve always wanted to run a marathon but never thought I would be able to complete it. I’m bookmarking this for the summer.

  54. Five running sessions a week seems like a lot. I trained for a half marathon (my first) last year with one long run a week, and a few sessions in the gym (weights, not cardio). As an over 40 female who is not ideally built for running, I find running more than twice a week to be tough on the old joints. I also make sure that the majority of each run is on soft surfaces.
    How would you adapt training to someone who needs to train less often?

  55. Thank you for this post! I don’t run marathons, but I really enjoy longer trail races and off road triathlons. I’ve been training and racing “clean” (primal diet, no carb loading, no sports drinks, no GU) for the past year and I am amazed at the results! I feel great during and after races and I am faster than I ever thought possible!

  56. Is anybody running or doing triathlons primal-ly and competing at a pretty high level? I started doing crossfit after finishing ironman wisconsin in september, and am having a mental struggle with the strength(weight) gains compared to an all aerobic plan. I say that long term health is my focus, but my fast run times are slowly drifting away (16:45 5k summer, 18:00 Turkey Trot),but i dont want to panic and revert back to chronic cardio.

  57. Sorry- should have noted i’ve been 80-90% primal diet for 18 months or so

    1. Are you using crossfit running workouts? or just lifting? How often are you lifting?

      Still eating your veggies? Careful of all those nuts!

      Remember, in the end, the first goal is to be healthy and fit. Even if it is at the expense of being fast.

      But I don’t think you need to lose speed.

      1. I’m mostly doing 4-5 WODs a week (mix of low rep strength work) and running at lunch time 4-5 days per week, but only 30ish miles. Not doing many intervals based on crossfit fatigue, so i guys its more of a question of balancing weights and intervals while getting enough recovery. And yes, lots of veggies, pretty much no nuts or fruit, some dairy (cheese). I could blame the beer, but i refuse to 🙂

        1. You might want to check out the programming on the Crossfit Endurance site ( They recommend about 4 WODs per week balanced with around 3 endurance workouts per week (1 interval, 1 Tempo, 1 longer distance). For multisport, they recommend I think 4 endurance workouts max (maybe 5), I am primarily a runner so not as well versed on that. Check it out though because they guy who runs it has done Ironman and they have several multi-sport athletes successfull using the program.

  58. I have run 9 marathons so far and I am planning to run number 10 this January. Most of the earlier marathons were done fueling with sugar, like gels and such. After I switched to a primarily primal diet I found that I didn’t need the packets of gel on my run. It was quite amazing to run the full 26.2 without feeling depleted. Just in case I run out of fuel during the run I have a small bag of dates that I bring with me. Most of the time I don’t even need them!

  59. Mark, I love the whole primal thing. I don’t embrace it fully, but try to do what I can! One question – I love doing spin classes at my gym. In a sense they are very much an interval training class (especially the RPM classes). I like to do 2 or 3 a week, 40 minutes each. Is this overdoing it?

  60. Good stuff in this article. So far, I have only run a half marathon but that one was up a 13,000 ft. mountain here in CO and back down. However, I think I would continue to keep some emphasis on strength and mobility training that is so often neglected in the endurance world. I know I did when I was training for my half and my hamstrings and upper body noticed it during the run when they were subjected to that much up and downhill running. Maybe we are talking about a slightly different beast there but I still believe many endurance athletes negelect their strength training in favor of the endurance they are training throughout the week. One of my favorite resources now ever since that experience has been the fine folks at Crossfit Endurance ( They share our belief in Paleo and many of Grok’s approaches to fitness including avoiding chronic endurance or LSD (Long Slow Distance), as they call it. Their method has guided many athletes through marathon and beyond to ultra distances on minimal endurance training but maximal, short and intense, training.

  61. Paul,

    Thats funny, I ordered the book: Born to run, the other day 🙂 looking forward reading it even more now.

    Thanks for the link, great article and even though I’m already sold to the whole barefootrunning idea I haven’t heard of the 100 up exercise. I will try it out for sure!


  62. I ran my second marathon (my first finish) this year in 7 hours. While I’m happy for the finish, I think I’m capable of a MUCH better time. I do have another marathon that I signed up for in May 2012, so the discovery of The Primal Blueprint and now this blog post are pretty timely for me. I’m looking forward to trying a more “primal” training method for my next marathon.

    I have a question about aerobic threshold that I have a feeling is pretty intuitive, but I just want confirmation…

    Right now, when I’m at 70-75% of my max heart rate, I’m only at a brisk walk. As I follow a Primal diet along with Primal fitness (long, slow exercise, lift heavy things, sprint once in a while), will I improve on this, for example, be able to jog lightly in this heart rate range? It seems like as I get healthier this would happen, but as I said, I need confirmation.

    Thanks fellow MDA readers!

    1. I know this is a delayed response, but for those that come after us I will offer this: If a brisk walk is 75 percent of your max then over time this will improve until you can jog or even better. I switched from to this method of training and dropped from running all my runs at 9:00 min/miles to brisk walks, then to 14 min miles, then 13, then 12 then 11. So now I am about 11 min/mile keeping my HR at 133. Eventually this should improve even more.

  63. i ran my one and only fueled by primal. pre race meal was baby food with protein powder and it was the best! i made my own goo using pureed dates. plain witha bit of salt was great. worst experience involved coffee, peanut butter and dates in a slurry that came straight back up…

  64. I think if Dean Karnazes can run 50 marathons in 50 states in 50 days. Running a marathon every now and again will be ok:)

  65. Does anybody have any input as to a general range of mileage for this type of training.

    For instance: for race pace Mark suggests adding a mile per week for at least twelve weeks. So are we looking at 15-20 mile race pace efforts here?

    Also what distance should the longest aerobic threshold run be? I know they should be dictated by effort to some extent, but I don’t understand the total mileages here…i.e 15 mile race pace + 15 mile AeT in one week?

  66. Thank you, thank you, thank you.

    Have your book, read your posts, do paleo…STILL want to check this off my bucket list…just one. Pretty please. 🙂

    Thanks bunches!

  67. BTW…currently run 5,10, 15k with no problem. Never done carbs, never done drinks…never needed to. I don’t get the need for carbs at all!

  68. Recently I walked a distance I think is close to a half-marathon carrying a backpack and bags full of food, water, and some other miscellaneous supplies after walking around much of the previous day without any sleep inbetween. I started around 3am and it took me until mid-morning or so. I was planing on going a bit more than twice the distance in order to leave a city I was sick of and return to my favourite town but I cut through a backyard and the property inhabitants called the police on me for it. The police caught up a little later and stopped to question me, then drove me the rest of the way to a destination I was allowed to designate. I don’t know if I would have been able to walk the whole way without stopping for sleep.
    I consumed a lot of carbs on the way – probably at least a few hundred grams – though I was noticeably more toned for a couple days after.
    I believe I should start running more. This morning while loitering on the sidewalk, enjoying poppy-seed-tea-coffee and attempting to create positive vibes with a new acquaintace who was skipping class and a friend of hers and someone that person new I saw some students running in pairs into my old high school and was told that it was because they are in a class called personal fitness and had to run around town looking for clues. I guess the class was recently introduced to the school because I knew nothing about it when I went there a few years ago.

    1. A little while later I returned to the city for a visit, which was supposed to be a night. Of course, the guy who’s mom drove me there got arrested the next day so I got stranded for about a week until I decided to walk back to the town. It took me all night with a few minor rest stops, a couple shots of vodka and molasses, some peanut butter, a ridiculous amount of organic coffee, agony (my feet were raw/blistered/rashed.. you wouldn’t want to see or smell them), and a couple hours sleep when I was almost there and the sun was coming up, but I guess I can say I’ve done a marathon now, albeit a hiking one.

  69. anybody have advice on weight training while following this plan?

    I’m going to use this plan and will continue to lift, but any words of wisdom from people who know more than i do about marathoning and lifting.


  70. This is almost exactly what the Hanson’s Marathon Method prescribes. And the one I use. I highly recommend it.

    Also to keep burning fat even more, check out a special supplement called UCAN at Love that stuff! #UCAN

  71. Great article and very applicable. Before I found Primal (or even Paleo) I set myself a goal to complete every triathlon distance up to and including the iron man. It’s a long story, but the short version is – I’d committed to run a marathon before I hit 40 and failed. At that point, having missed my target – simply running a marathon would never have felt like an achievement. So I had to up the ante and as a keen cyclist (completed Lands End to John O’Groats 1,000 miles here in the UK a few years back “just for fun”) and swimmer (various river / lake swims up to about 3.5km) – so it made sense to try the multi-sport route and the Iron Man is of course the ultimate.
    I did recognise after reading the Primal Blueprint that I’d set myself up for some Chronic Cardio but a goal is a goal and an achievement an achievement. As a result I’ve deliberately spread things out and aimed for one major target per year (novice, super sprint, sprint, olympic and half iron man last year). I’ve done a few other sprints in between as they’re great practise for transitions and also because I actually really enjoy them – not too long to complete, and the training required – in my view – does not constitutes chronic amounts of cardio.
    I’m always going to be a “try athlete” rather than triathlete – coming in at the back of the pack – but I’m happy to complete, not compete which means it’s easier to stay firmly in fat burning territory anyway.
    After completing my half iron man last year I had a really bad year personally and my training and diet went completely to pot (put on about 40 lbs!). So naturally to get myself back into the swing of things I’ve now signed up for The Big One – my Iron Man distance event – in July next year. I’ve got plenty of time to train and already have a reasonably good base of fitness and primal experience to build on obviously but this article has really helped me get focused with my training plans. Obviously it’s single discipline so I’ll need to adapt it to multisport but the concepts the same.
    As always, great intel from Mark! 🙂

  72. Good advice. I’m running long run 22 to 30km first thing in morning with on a coffee and tablespoon of cream (not sure if that’s ‘primal’) This has indeed acclimated my body to fat burn. Add in a little energy drink or gel to replicate race day and you are steaming. Interval training idea has also worked, hate doing them but they have built speed and strangely strength