CrossFit’s Criticism: How Do I Eat Enough Carbs on Primal?

Word CarbsBy far the single most common criticism levied against paleo by CrossFitters is that it’s too damn difficult to eat enough carbs to maintain performance during workouts. There is definitely truth there.

First, let’s establish something. Do CrossFitters indeed need more carbs than your average Primal bear?


CrossFit workouts are intense. Your muscles need fuel to support intense movements, and they need it immediately and repeatedly. Glycogen just works better for that. It’s a matter of logistics. Glycogen is right there in the muscle, ready to go. It’s settled, sedentary, tethered. The fatty acids we burn are unencumbered, nomadic, going where they’re needed. That’s why we call them free fatty acids.

Furthermore, glycogen requires less oxygen to burn than fat. As your average CrossFit workout has you out of breath within the first minute or two, glycogen is a CrossFitter’s best friend.

If you don’t believe me, perhaps this 2016 study will convince you. It was a unique one because they took actual CrossFitters following a moderate-low-carb diet (around 200-ish grams per day) and separated them into two groups. One group stayed moderate-low, the other bumped their intake up to 400-500+ grams per day. Both maintained normal 3 on, 1 off CrossFit training schedules. They gave performance tests before and after the diet shift, using the Rahoi WOD (as many rounds as possible in 12 minutes of 12 box jumps, 6 95-lb thrusters, 6 bar-facing burpees). The higher carb group saw bigger improvements than the moderate carb group—an 11.1% improvement vs a 4.5% improvement.

Clearly, both groups were able to improve performance. However, if performance is your PRIMARY goal, then more (especially quality) carbs are likely to help. I’ll cover more on goals in a future post….

But isn’t Primal low-carb?

Standard Primal defaults to lower carb because it’s enough for most people. If you take a look at the Primal Blueprint Carb Curve, you’ll notice that 150 grams/day is the recommended level for people interested in maintaining body weight and supporting an active lifestyle. As anyone with a decent head on their shoulders, a cursory knowledge of how fat, carbs, and protein work, and functioning eyes can tell you, the vast majority of the population has no business consuming a high-carb diet. Few people do the type of work that requires “carb-loading.” As a result, 150 grams is plenty for your average man or woman.

Many of my readers got into Primal looking to lose weight, and low-carb, high-fat is the simplest, most effective way for most people to do that. 

I’m doing a keto experiment right now, and I’ve got a keto book coming out in a few months that will talk more about that choice and the science behind it. Personally, I run best on high-fat. It works for my goals, desires, and predilections. 

But the beauty of this way of life is that what I or anyone else eats does not determine what you “have to” eat.

Primal’s flexible, remember?

Allow me to dispense with some common misconceptions about Primal eating and carbohydrates that CrossFitters might hold:

We’re not against carbs. Carbs are an elective source of calories to be divvied out according to training volume, performance goals, and individual variation in tolerance/desire. If you’re regularly engaging in CrossFit WODS or other types of anaerobic activity (e.g. HIIT, sprinting, heavy lifting, mid-to-high intensity endurance training, sports like soccer, basketball, football), you should probably eat around 100 extra grams per hour of anaerobic output. If I come off as a carb basher, it’s only because I assume that most people aren’t doing the kind of activity that warrants carb-loading. CrossFitters are not those people. They can use the carbs.

We don’t carb-load with kale. All those horror stories of paleo CrossFitters trying to replenish glycogen by eating four pounds of broccoli in a single sitting? That doesn’t happen on Primal. Around here, above ground vegetables—leafy greens, cruciferous vegetables, summer squash, mushrooms, asparagus, and other non-starchy plant matter—are fair game. They don’t “count” against your carb intake, either because it’s more fiber than glucose or because it takes more glucose to digest than it provides.

We’re more concerned with carb quality, not quantity. Nutrient-poor, refined sources of carbohydrates might refill glycogen, but that’s about all they do. If you need more glycogen, it’s far more advantageous to your health and your performance to get it through nutrient-dense, whole sources of carbohydrate. To do otherwise is just missing an easy opportunity for more micronutrients.

What are some starchy or carb-rich foods one can eat on Primal?

  • Potatoes. Long maligned on orthodox paleo, potatoes are totally fine on Primal. If you cook, then cool them, they’ll generate resistant starch, a prebiotic that feeds healthy gut bacteria. And the basic white potato is far more nutritious than most people claim. It’s high in potassium, magnesium, and it’s even a source of complete protein.
  • Sweet potatoes. Purple, white, orange—they’re all good. If you’re putting your body through the wringer, eat purple sweet potatoes; the polyphenols offer protection against exercise-induced oxidative stress.
  • Bananas. Eat ’em ripe and you’ll get a big dose of glucose. Eat ’em on the greener side and you’ll get a big dose of resistant starch. Either way, you get the potassium—a crucial electrolyte.
  • Plantains. You’ve probably had them at a Cuban or Jamaican restaurant. You loved them, didn’t you? Get yourself to a Caribbean market and buy some plantains, gently sauté them in a little fat, and eat with some good sour cream on the side. Your glycogen-starved muscles will thank you.
  • Rice. Pure glucose. Little in the way of micronutrients, but you can amend that by cooking the rice in bone broth, adding trace mineral drops to the cooking liquid, and cooking and cooling the rice to increase the resistant starch content.
  • Legumes (if tolerated). Check out my recent post explaining why I changed my stance. Excellent sources of fiber, minerals, and phytonutrients (particularly the colorful ones). Plus, legume protein, while not complete, can supplement and augment the animal protein you eat.
  • Dairy. Lactose is half glucose, half galactose; a similar mix was recently shown to enhance glycogen repletion after exercise. And milk drinking improves muscle protein synthesis after exercise and performance during exercise. Dairy also provides protein and calcium, which you need to stem the exercise-induced increase in parathyroid hormone and to strengthen your bones.

By now, it’s clear that you can eat as many carbs as you need on a Primal eating plan. There’s nothing stopping you. You won’t butt up against any rigid ideology.

However, there are some things to keep in mind before you start mainlining Japanese sweet potatoes.

Once replenished, muscle glycogen doesn’t disappear. If you refill your glycogen stores with a huge post-workout sweet potato, walking the dog, playing with your kids, or going shopping will barely budge your muscle glycogen. When the next workout rolls around, you’ll be ready.

Carb cycling is an option. Eat high carb on training days, low carb on rest days. It works for elite athletes’ performance just as well as around-the-clock high-carb.

I can’t tell anyone what to do. I can give good information that represents the science as I understand it, and the rest is up to you. And I always recommended an N=1 experiment. Take careful note of of how many carbs you ate on any given day, when you ate them, and how you felt, performed and slept. See what you notice.

For what it’s worth, I have it on very good authority that you can get enough carbs while staying Primal to support and improve your performance in CrossFit.

Thanks for reading, everyone. Stay tuned for the next installment of the series next week.

This article was co-written with Laura Rupsis, Level 1 CrossFit Certified, Primal Health Coach Certified, and owner of Absolution CrossFit in La Grange, IL.

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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28 thoughts on “CrossFit’s Criticism: How Do I Eat Enough Carbs on Primal?”

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  1. Did Crossfit for a year, doing the 5AM WODs (schedule restrictions precluded otherwise). The higher carbs pre-workout, lower carbs post was an excellent tool. However, getting enough sleep to make full recoveries was an issue… sleep is just as important (probably more) for performance on the next WOD. I even tried pre-WOD caffeine to little benefit… low total hours of sleep will nip any other strategies (carb loading, caffeine, energy drinks) in the butt and affect performance.

  2. Great post and great series of blogs. (Looking forward to all of them) and exactly what I have been looking for. I have been Primal for years though have always had to add more carbs due to training in crossfit, mountain biking, hiking, etc. Recently I started playing around with macros and realized how hard it is to get the required carbs. I started to eat more oats and rice which I normally don’t do. I can only have small amounts of sweet potatoes as they tend to cause GI distress. I stick to white/red potatoes and purple sweet as yams tend to cause more bloating. I did notice once I increased my carbs, I was PR my airdyne workouts. Interesting stuff.

  3. I workout first thing in the morning before eating anything. I have experiment with many different carb sources and amounts pre workout but never noticed much difference. Perhaps I wasn’t eating them early enough before the workout. I found the biggest difference came from what I ate the day before. I will occasionally fast until dinner and have definitely noticed a performance dip the day after. Thanks for addressing this.

  4. My view is that if you’re 90% of the population – enough rest between workouts and not training 5 days a week- then you don’t need carbs post workout or to spur stronger workouts. For those just looking for general fitness and to be slimmer, it’s not necessary. You’re not looking to compete in a competition where even 5% means something. Yes, this includes crossfit. Even high intensity workouts. As long as there is enough rest in between workout sessions. Unless you’re competing, you can get by just fine on low to no carbs.

    If you’re an athlete or perform in competitive competitions it may help, though.

    1. I’m right there with you. I saw a gradual decrease in the number of WODs per week I could tolerate in between recovery times (itself another under appreciated facet of training). Eventually I felt like 1x/week HIIT was plenty, with other skills/strength work in between. Recovery + sleep > carbs. In fact, with that amount of recovery time, I was hitting personal records and skills all of a sudden that were priorly unattainable on a 3-4x/wk routine.

    2. You have it right, Grant. Most of these people are delusional about their nutrition needs.

      As I stated above, there is a huge difference between fine-tuning one’s diet as a pro athlete in either a burst sport or an endurance sport vs schlubs who schlep to the gym so they can pump their pecs for Friday night showing off on the dance floor.

      CrossFit is merely an exercise cult that seems to promote lifts like Oly lifts that are far too dangerous to do for the going-to-the-gym-after-work crowd.

  5. Informative read. I have been subsisting mostly on sweet potatoes as a primary carb source. The green vegetables I consume are merely a delicious filler that is paired with lean meats for complete meals. I find that on heavy lifting days i need them pre and post workout. On days that I may have failed to consume adequate quality carbs I certainly feel weaker and less capable.

    My only issue is that after a lifetime of being overweight my initial instinct is always to restrict carbs when in fact I know that I need more.

    1. Like you Dave I have always been overweight and I probably worry more than I should about how many I’m getting (last night I was literally trying to mental math how many were in my cabbage/spinach/zucchini that I’d sautéed with ground beef before I realized I was being absurd). For the average person, I think Mark’s guideline of 150 is plenty generous for maintenance and lower as you need for weight loss

  6. Don’t do CrossFit but I do eat black rice, it seems to be more nutrient dense than white rice and I believe it has more antioxidants. I also do a little quinoa. Please don’t hate me for that. 🙂

  7. What about winter squash? I find it confusing that winter squash is not included in the starchy veg section. I have read the most updated Primal Blueprint book. There’s one small paragraph regarding winter squash being OK, yet the diagram still shows winter squash as part of the moderate carb group.

  8. I’m 207lbs, ~15% body fat at age 60. I l (generally) lift weights on Monday, Friday, and next week Wednesday. If I miss a weight day I don’t sweet it, because I don’t lose strength conditioning. Weights usually take about 30 minutes. I do sprints about 4 – 5 times per month. In between those days I’ll try to do some 180-age heart rate aerobics. In my early 20s (the 1970s before I or most people heard about steroids) I’d lift for 2 hours 6 days per week (including running as well)….because, well that’s what Franco Columbu and Arnold did. I got very over trained and ended up with a low back injury which laid me off for a year. When I got back to lifting Mike Mentzer was on the scene and I took his advice. For me it was, “How did this guy become Mr Universe only lifting for 40 minutes 4 days per week?” It worked and I gained up to 200+. I’ve never done steroids, every. But the best muscle gains I ever made was in my late 20s following Dr Ellington Darden’s High Intensity Bodybuilding book. I gained about 2lb per week for about 6 weeks doing three 20 set, full body workouts per week (MWF) I went from 202lb to 216lbs. My training partner gained more. But at the end of those 6 weeks we were toast and over trained and had to lay off. When I was 47 years old I cut back to hitting each body part only once per week and my bench went up to 365lbs. I thought I’d get 400lb but my shoulder joints went to hurting. Turns out I had developed some arthritis from the excess training that was confirmed at the Cooper Clinic’s body scan. At 60 I wish I could take what I know now back to my 20s and start over. I would’ve been more rested, better at burning fat, and better at aerobic conditioning.

    Cross Fit? OK, I would’ve experimented with it in my youth for sure. If I could go back I’d play around with it but I’d still give myself way more rest between workouts. For me, I cannot see how doing glycolytic WODs are going to build much in the way of aerobic fitness.

    1. Oh, I wouldn’t just be more rested. The workout I’m doing these days is both effective and sustainable. No forced layoffs due to accumulated fatigue and over training.

  9. Great post Mark!

    After much experimentation I have found I function far better on a high carb diet. I’m extremely efficient at processing carbs- it is definitely the macronutrient that fills me up & turns off my hunger most effectively.

    I’m extemely thin & wiry- always have been, & just run far better on carbohydrates. I came to primal to deal with celiac disease + several autoimmune issues- & not for weight loss though.

    I’d love a post on how to maximise a high carb diet for nutrient density & any possible vitamin deficienes that may arise as a result of eating less fat & protein.

    I tend to eat a lot of shellfish to cover my bases, but always appreciate your insightful input Mark.



  10. The study Sisson cites suffers from flaws.

    The study fails simply because there is no control. The same CrossFitters should have been used on both the moderate carb and higher carb diets by done thusly for each trial run:

    1. Have them not work out for 96 hours.
    2. Test them on the Rahoi WOD
    3. Have them eat a moderate carb diet for six weeks
    4. Test them Rahoi WOD
    5. Have them not work out for 96 hours.
    6. Test them on the Rahoi WOD
    7. Have them eat a high carb diet for six weeks
    8. Test them Rahoi WOD

    Understandably, Sisson is worked to brand a diet plan as his way of earning a living. It seems to be Mark’s passion.

    However, all anyone needs is to follow these rules:

    1. Do not eat regularly (subsist upon) cheap grain-based food: wheat bread, pasta, pie crust, cakes, cupcakes; corn tortillas, corn-on-the-cob, corn syrup; rice. If you can, try never to eat these. However, a slice of cake at a celebration won’t kill you.

    2. Do not drink pop by the gallons weekly and never corn syrup based products.

    3. Don’t eat packaged food, especially frozen TV dinner style dinners.

    4. Eat eggs, cold water fish, beef, poultry, pork, seeds, nuts, berries, tree fruit, vine fruit, citrus fruit, tropical fruit, onions, scallions, garlic, roots, leafy greens, dairy, gourds.

    5. Make most of your diet a mix protein (your biochemistry runs on protein, muscles are protein) and fats as fats break down into energy. Carb-based food should be consumed for the vitamin and mineral contents because good carb-based foods are laden with the micronutrients that you need.

    6. You’re going to to die eventually. No one day should make or break your health and fitness.

    There is a big difference between being a pro athlete and fine-tuning one’s diet for a burst sport (tennis, rugby, football, ice hockey) vs an endurance sport (distance rowing, distance running) and eating well to go workout in a CrossFit gym or a park.

    There is so much difference and so much science into the former that any blog blather about the latter appears to be a thinly veiled attempt at appealing to more would-be customers.l

  11. The study cited by Mark above is pseudo-scientific. The study fails to control for variations of athletic ability among the athletes of the two groups.

    An actual scientific study would use the same set of athlete-dieters first exposing them to a low-carb diet and later, after a reset, exposing them to a higher carb diet.

    1. Have them not work out for 96 hours.
    2. Test them on the Rahoi WOD
    3. Have them eat a moderate carb diet for six weeks
    4. Test them Rahoi WOD
    5. Have them not work out for 96 hours.
    6. Test them on the Rahoi WOD
    7. Have them eat a high carb diet for six weeks
    8. Test them Rahoi WOD

    There is a big difference between being a pro athlete and fine-tuning one’s diet for a burst sport (tennis, rugby, football, ice hockey) vs an endurance sport (distance rowing, distance running) and eating well enough to sustain a CrossFit workout. The former requires fine-tooth science. The latter does not.

  12. I cannot fully agree with that.
    Just have a closer look at the FASTER Study by Volek & Phinney, it seems that muscle glycogen is filled up automatically after workout without any post-workout carbs. The process why this is is not fully known, it seems that lactate is converted to glycogen – very intersting process! But this happens only if you’re long time fat adapted / keto,

  13. I like the thought of fatty acids as hobos travelling the vein roads of the body, while glycogen is sedentary and settled in muscle villages. The fat comes off as more paleoish.

    On a more serious note, how about dried fruits as a quick carb source?

  14. Something I’m noticing in myself and often see in other’s comments is that going fairly hard-core keto works well for many people, and being a bit higher carb, like 150 grams per day or so works well for many, but being on the border between the two or veering back and forth seems to create A1C problems, possibly triglyceride problems, and sometimes energy and performance problems. This is doubly problematic because we (at least I) like to think of health and diet as a fairly linear trend with more fat burning being better, but I’m beginning to doubt this is always the case. It seems like the body can’t optimize for either if one is on the fence. I would be very interested in thoughts on this.

    I recently added pre-workout fast carbs to an otherwise fairly LCHF diet and that seems to have made a big improvement in my workout energy levels

  15. I do not do CrossFit, but do train hard with weights, sprints, etc.

    My carb intake has always been between 150-250 carbs a day and I always felt and looked my best with that. If I dipped below my workouts and mood suffer.

    Great to see your recommendations fall in line with that!

    Tons of meat, veggies, potatoes, and white rice for me! 🙂

  16. I’d like to know if someone is fat adapted and employs a cyclical or targeted ketogenic diet can get the same or better results doing competitive crossfit as someone who eats a high carb diet. Any thoughts?

  17. Well said Mark. I’ve written about the topic before and I really think that a lot of Crossfitters make their life harder by under eating starchy carbohydrates for the reasons that you mentioned.

    That being said, I’m not sure if you’ve noticed the trend with “Instagram coaches” who are so fond of advocating how their clients eat upwards of 500 grams of carbs per day (for females, males go higher). They apparently continually get leaner too.

    While I have zero doubt that athletes whom train multiple times per day need more carbs, I find these numbers incredibly high even if an athlete is “running through the carbs” like these coaches say.

    I can see the need for a refeed but you have to imagine that carbohydrates at amount, regardless of how “good” the carbs are is going to cause a whole host of insulin issues.

  18. This is why I recommended cycling in more carbs on rest days. I personally have more effective workouts when training in a ketogenic, semi-fasted state then replenishing glycogen stores every week with clean carbs like those mentioned here.

  19. There are so many more primal sources of high-carb, high-energy foods than are mentioned here… Don’t forget winter squash, turnips, parsnips, beets, plantains… And if you need calorie-density, fry starchy things such as potatoes and plantains in bacon fat til they are crispy! Delicious, nutrient-dense, and sustaining fuel! Use your food imagination!

  20. I can say that after 7-10 days of low carb and doing jiu jitsu and calisthenics. I feel run down. Ive replenished with both donuts and cookies once and sushi and bananas the other. Both gave me a massive insulin bomb that kickstarted my leptin and my body for the next 7-10 days of primal.