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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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August 17, 2017

CrossFit Training: How to Support Overall Wellness and Longevity with Primal

By Mark Sisson

Close-up of man holding heavy kettlebell at gymThere are some who hold the view that at birth, each of us is allotted a finite supply of energy which exercise depletes, thus hastening our demise. An intense regimen like CrossFit, in this paradigm, would hasten a person’s demise.

That’s wrong, of course. Those who remain sedentary their entire lives often have short, miserable ones, while regular exercisers enjoy better health throughout their time on earth. Exercise has real potential to prolong life and compress morbidity. But it is a major stressor that, if applied incorrectly or excessively, can reduce health and overall wellness.

Here’s the good news for CrossFitters and anyone else engaged in similar combinations of aerobic, strength, and anaerobic training:

Strength training promotes healthy longevity, even in people with hip fractures.

The stronger your grip, the longer you live (even if you’re overweight).

The more lean mass you carry, the better you’ll survive injuries and disease.

The more briskly you walk, the lower your mortality risk.

The more functionally capable you are, the longer you’ll stick around on this rock.

In heart failure patients, a combo of endurance and resistance training is better for long term outlook than just endurance training.

Sound familiar? Between all the deadlifts, the squats, the box jumps, the multi-modal development of fitness across multiple energy pathways, the muscle endurance, and the strength, CrossFit appears to support all the pro-longevity factors listed above.

But there are some things to watch out for that could derail your health and longevity—and going Primal can help.


Injuries are a fact of life. Anyone who pushes their body to the limits will eventually overstep them. That’s okay, but you can increase your body’s resistance to injury with a few Primal interventions. Namely:

  • The increase in collagen intake, which supports connective tissue health.
  • The regular consumption of omega-3-rich seafood and reduction in omega-6-rich seed oil consumption, which improves inflammatory status.
  • The elimination of gut irritating-foods like gluten grains, which reduces gut inflammation and prevents excessive intestinal permeability.
  • The consumption of full-fat dairy, which provides vital calcium and anti-inflammatory fatty acids.
  • The promotion of barefoot living, which, provided you go slowly and gradually, increases foot strength, ankle stability, and proprioception.
  • The forays into ketosis, which increase anti-inflammatory ketone bodies.
  • Add these uniquely-Primal interventions to a CrossFitter’s rock-solid technique, ample mobility training, good sleep, and mind-body intuition and you’ll have a better shot at staying injury-free.

Fat Adaptation

Any CrossFit athlete interested in living a long, healthy life should devote at least three or four weeks to getting fat-adapted. Going full-on ketogenic is the quickest way to do it, and easier and more congruent with your training schedule than you might think, but you can go basic low-carb, too. And you don’t have to stay there.

Hit the point where the low-carb/keto flu stops. Where you start feeling good (consistent energy throughout the day, no more headaches or irritability, no more carb cravings, steady appetite, lucid thoughts). That’s the signal that fat-burning mitochondria are ramping up.

Stay there for 2-3 more weeks. Really get settled, get those fat-burning systems established.

Then, try the cyclical low-carb approach I described in a previous post. High-carb on training days, lower-carb on rest days. That should be enough to maintain your fat-burning machinery while replenishing your glycogen for future endeavors.

Excess Carbs

All else being equal, it’s a good idea to burn as much fat as you can and as little glucose. Burn the glucose you’ve earned, of course. I’ve always said that. But don’t eat extra if you don’t have to. Insulin you don’t really need will only hurt longevity.

CrossFit is carb-intensive, as I’ve covered before and anyone who’s actually attended a box for more than a month can attest. So while you’re not going to go low-carb, go as low as you can while still maintaining your performance or hitting your performance goals. If you want to improve your performance, you’ll probably eat more. If you want to maintain, you’ll probably need less. But the point is that most of us are eating more than we need and can probably drop the carbs and, thus, the insulin, a bit without compromising our performance.

Excess Protein

CrossFit compels a high protein intake. You come home from lugging around heavy iron and manipulating your own bodyweight and a large steak starts sounding very, very good for a very good reason: Your muscles require the protein it contains. But is excess protein a problem?

The link between protein and longevity is a tricky one. In short to medium-term studies, high protein intakes are great. They’re safe (as long as you don’t have pre-existing kidney trouble), they help people lose body fat and retain lean mass, they promote satiety and reduce hunger, and they improve body composition, especially if you’re lifting heavy things.

I’m not exactly sure where I come down on this. We don’t have any strong direct evidence that high protein intakes reduce longevity in humans. If anything, older folks need more protein to derive the same effects because they’re less efficient at processing it. Some research suggests higher meat intakes are linked to better longevity in the elderly.

That said, protein does elevate mTOR, a pathway that, if activated to excess or without respite, does reduce lifespan in animal models and may promote the growth of tumors. When mTOR is activated, autophagy—cellular cleanup of damage, necessary for health aging—shuts off. Yet mTOR also increases muscle protein synthesis. In short, it’s the “growth” pathway.

A nice middle ground is intermittent protein fasting. Every once in awhile, eat less meat than you normally would. Or fast outright. This allows you to take advantage of the benefits of mTOR (muscle building) while giving you the benefits of mTOR restriction (autophagy).


Overtraining is a constant concern for any elite athlete. CrossFit is particularly demanding.

You have your training schedule, and I’m not trying to change that. Adopting any of the Primal lifestyle laws (and honorable mentions) will improve your resistance to stress of all kinds, make you more robust in the face of your demanding training schedule.

Lack of Collagen

Skinless chicken breasts, whey protein isolate, egg whites, and other similar foods are staples in many CrossFitters’ diets because they’re extremely high in protein. They’re also extremely high in methionine, an essential amino acid. The thing about methionine is that it increases our need for glycine, an inessential amino acid found in collagen.

The more methionine-rich meat we eat, the more glycine our bodies utilize. In rat studies, high methionine diets reduce lifespan. If you add glycine to the high-methionine diet, however, the rats live longer. For a CrossFitter slamming protein and lean chicken breasts, balancing the methionine with glycine could mean throwing in some oxtail stew, bone broth, and collagen powder. Pretty simple (and delicious).

Glycine may also impact your risk for various degenerative diseases often linked to “meat consumption.” In one study, controlling for glycine status abolished the link between red meat and diabetes. In another, low levels of glycine in the blood predicted the risk of diabetes. While it’s not as if the average CrossFitter is at risk for diabetes, this data is compelling evidence that muscle meat intake should be balanced with collagen intake for healthy longevity.

Performance and health are often cast as opposites. I reject that. I’m convinced that, using Primal principles, a CrossFitter can maintain and improve performance without sacrificing his or her short-term or long-term health.

What about you?

Thanks for reading today, everybody. Have a great end to your week.


TAGS:  Aging, mobility

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18 Comments on "CrossFit Training: How to Support Overall Wellness and Longevity with Primal"


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Elizabeth Resnick
1 month 5 days ago

Interesting about the “intermittent protein fasting.” I find this is something I kind of do without even thinking about it. I believe that when we are feeding our bodies real food, they will tell us what we need. From time to time I’ll have a day that is very low in protein…mostly veggies and fat, with the only protein coming from the collagen in my coffee. But that’s just what my body is craving that day.

1 month 5 days ago

I could eat a truckload of veggies, but protein? Not so much. I find that protein of any kind loses its appeal when my body has had enough, possibly because it’s so satiating. However, I usually do require at least some protein at every meal in order to feel and function optimally. Based on that and the fact that a brief stint as a vegetarian adversely affected my health, I don’t think protein fasting would work well for me.

Aaron H
Aaron H
1 month 5 days ago
I consume minimal protein but also like you high fat and veggies particularly if for some reason there is a longer period of time in between my most intense work outs like maybe 3 to 4 days. Work does it to me sometimes. I feel protein is barely needed during those lower activity days. If I do eat protein during those times it’s from eggs usually and likely as a compliment to a veggie stir fry. I usually make a pan sauce for veggies using collagen from bones and the rest a more liquid bone broth. So different kinds of… Read more »
1 month 5 days ago

Solid shade in that lede, Mark.

1 month 5 days ago

+1 ???

1 month 4 days ago

Glad I’m not the only one that picked up on it! 🙂

Jimmy Smith
1 month 5 days ago

I like that you mentioned the line between low carb and low carb for performance. I often think that the general fitness population lumps all types of “low carb” into a low carb diet as opposed to what you need to eat for your various daily goals. When you play with your carb levels based on activity, you can unlock some pretty cool performance benefits.

Even the Strong
1 month 5 days ago
Yup, I definitely was confused about low carb until recently. I knew it was hurting my performance but I was sticking with 100-150 g per day just because I really liked the benefits of fat adaptation. Thought it was an either/or deal. But since this series started I’ve upped my carb intake (not even really measuring, just going for it when it feels right and sticking to primal sources) and felt much better in the gym, while still showing the signs of fat adaptation that I love so much, like being able to skip or delay a meal without any… Read more »
1 month 5 days ago

Bummer. Out of stock on the collagen protein powder. Would like to try it. Time estimate on when it will be back in stock?

1 month 5 days ago

I have carpal metacarpal arthritis, so I’m walking as fast as I can….

1 month 5 days ago

I dont do crossfit but this is a great all-round lifestyle template.

1 month 5 days ago
Finding a challenge staying Primal when doing Muay Thai (other than the martial arts, its also incorporating lifting to build muscle), I cannot lie. Potatoes are very necessary things (primal), but wheat bread a very convenient substitute (not primal!) way too easily available in delicious toasty buttery temptation right underneath the dojo… Wheat does me ill, but tastes so good after a crazy workout… The exertions of Muay Thai are teaching me new things about my body. While playing around with carb cycling, keto and IF, I have noticed dips in performance on clean eating and intermittent fasting the day… Read more »
1 month 4 days ago

Hey Mark, are you collaborting with crossfit? It seems to have become the focus of your blog

Tom Nikkola
1 month 1 day ago

Cool stuff about the glycine. I take it before bed but haven’t come across the benefits you wrote about in connection to methionine.

Andrew H
Andrew H
1 month 23 hours ago

I wonder how often is recommended for an intermittent protein fast? I only rarely do full fasts of 36 hours or longer, maybe three times a year.

18 days 8 hours ago

cross fit = chronic cardio