A Letter to SFH, re: Glycogen Reloading

This entry is a response to a post by the good folks over at Stronger, Faster, Healthier. They are a company that I do truly respect; I promote the heck out of their high-quality fish oil (and use it myself) and I admire the commitment they have to putting out excellent products amid a sea of imitators. It is my sole desire to create an open dialogue here, and not to attack or disparage them in any way, and I hope that readers will keep the same goals in mind when commenting.


An athlete at our gym sent me tweet last week saying that he was now uncertain whether or not he should be eating sweet potatoes post-workout, based on what he read on the Stronger, Faster, Healthier blog (the post in question is here, do not read further until you read it first). It’s a well-known fact that I promote starchy carbs (sweet potatoes, taro, squashes, etc.) post-workout in order to refill glycogen spent during intense exercise (like CrossFit). It’s something that has worked very well for me personally, as well as for my clients. So I was naturally curious to see what SFH had to say on the topic. Sadly, it left me disappointed.


“In order to understand glycogen re-loading, one needs to know a little biochemistry.”


We definitely agree on the mechanisms for glycogen synthesis and I definitely agree that the increased insulin sensitivity that comes from exercise is sufficient to transport nutrients where they need to go in that 30-60 minutes post-workout window. But that’s where the agreement stops.


The next section serves to vilify insulin spiking. On the whole, I tend to think excess insulin spiking post-workout is largely unnecessary, and most of the bodybuilders out there who are doing it are quite insulin resistant already, which is why they need a huge insulin spike to transport nutrients into cells. But do I think a short-term rise in insulin in a 30-minute to 2 hour window is a bad thing? No, as long as those insulin levels return to normal, which they do when eating an anti-inflammatory diet based around whole, nutrient dense food. The claim that

over-stimulating insulin after exercise becomes a pathophysiologic risk factor for follow on heart, vascular and inflammatory disease

lacks proof and incorrectly creates the assumption that the risk factors due to chronically-elevated insulin levels (as seen in metabolically deranged individuals) occur with the same frequency and magnitude in individuals who are only spiking insulin post-workout. The statement is comparing apples to oranges; the physiological state of chronically-inflamed, metabolically-deranged people is completely different from healthy, Paleo -eating, hard-training individuals.



The above image is incredibly misleading. The implication here is that a single serving of sweet potatoes will spike insulin more than whey protein, and that is simply untrue. Whey proteins in general spike insulin.  As a part of milk, that insulin response is needed so that animals can shuttle as many amino acids into the body as possible for growth. And studies, like this one, have shown that whey is incredibly insulinogenic (again, not necessarily a bad thing in an acute setting), so don’t pretend for a second that whey is some white knight compared to a sweet potato. It makes no sense to disparage an insulinogenic food in order to replace it with something that is also insulinogenic, but a non-food.


Furthermore, the goal of eating sweet potatoes is not to spike insulin. It is to replace glycogen that has been depleted during exercise. Not replenishing muscle glycogen can lead to serious side effects, namely burning off liver glycogen, then brain glucose, which can lead to a shutdown of neurons firing, which I don’t have to tell you is a very bad thing. Think about your body as a hybrid car, where the gasoline is your glycogen/carbs and the electric system is your fat stores. When you’re cruising around town (light runs, light weightlifting) you can be in electric (fat oxidation) mode and do just fine. But if you need to accelerate hard (CrossFit, hard runs, sports) you have to use some gas (glycogen/carbs) because the electric system can’t keep up on it’s own. Continue to try accelerating without any gas in the tank and you either aren’t going to go anywhere or your car is going to breakdown. If you aren’t refueling yourself with good post-workout carbohydrates, you will burn through your glycogen and your health and gym performance will suffer. A great anecdote is provided by Mat LaLonde, as a guest on The Paleo Solution podcast (minute 44). Also worth mentioning is that continual glycolitic work done on a low-carb diet has the potential to elevate cortisol to unmanageable levels. This can lead to a state of constant stress which leads to fat retention and adrenal fatigue. Bottom line: if you’re doing glycolytically-demanding work, you need to eat glucose to replace spent glycogen.


Now, SFH claims that “At Stronger Faster Healthier, we emphasize energy regeneration as a first step,” but the subsequent sentences about ATP depletion, near-death in cells, and their “ATP package”, lead me to think that there is a disconnect between the product they are selling and how our bodies actually work during exercise. There are three energy systems in the body: Phosphagenic, Glycolitic and Oxidative (Aerobic). These systems work in beautiful concert to provide you with the energy you need for your workout. The statement that

After a workout, cellular energy (ATP) is depleted. Our cells are at a low energy state and in some cases just able to survive while stores of ATP build back up.

is a severe exaggeration. The entire purpose of the Phosphagenic pathway is to make use of ATP in a quick burst and then have the Glycolytic pathway continue producing ATP from glycogen stores. To say anything other than this without sufficient proof is to be disingenuous to the science of metabolism and exercise. And seriously, if your cells are in the near-death state they describe, go see a doctor, as that’s the kind of cellular behavior seen in folks with severe insulin resistance or cardiac disease.

To summarize, our bodies, after a rigorous workout, are primed to burn fat. In fact having depleted the available glycogen stores, our bodies become fat burners. Now add back sugar and high glycemic carbs and our bodies switch back to sugar users and excessive insulin spiking. This is not a good plan.

I don’t even know what to do with this section. We’ve already established that depleting glycogen stores and leaving them that way is a bad thing, but depriving it of the moderate to high-glycemic carbs it needs to replenish those stores is just setting you up for further failure.


So what do they recommend after taking your recovery drink? An apple. This is not the best idea as excess fructose (yes a sweet potato has some fructose, but it represents less than 10% of the total sugars) like that found in most fruit upregulates glucokinase within the GLUT2 metabolic pathway and shuttles most sugar (glucose and fructose) to the liver first, since that is the only organ that can process fructose. That means when you should be filling up your muscle glycogen, you’re wasting precious time filling your liver glycogen first. Your recovery will really suffer if this happens.


The last sentence of the post is worth mentioning as well: “Avoid supplements that have excessive carbohydrates in them, especially after exercise when insulin sensitivity is high and our bodies are primed to over release insulin.” Yes, our bodies become more insulin sensitive post-workout, but it does not mean the we are “primed” to release more insulin. Rather, being more insulin sensitive means that your body needs to release less insulin to deal with the same amount of carbohydrates. So while you should avoid non-food supplements in general, avoid them because real food is a better choice, not because of insulin sensitivity.


So, what should you do after you work out hard, like after a run or a CrossFit WOD? Simple:

- Within 30-60 minutes, eat some lean protein (we don’t want fat to slow down digestion) and some starchy carbs.

- Make eating real food a priority

- Leave the fruit out of it.

- Bring it with you to the gym.

Your post-workout meal is your bonus meal for all the hard work you did and all the muscle you’re going to grow. Don’t underfeed yourself by making a normally scheduled meal your PWO meal; you need extra nutrition to support your training.

I encourage SFH to reply and clarify any of their positions or challenge any of my assertions. Ultimately, we’re both in the business of making people healthier and open discourse is very valuable in achieving that goal.



The Lazy Caveman
  • http://crossfitwesthouston.com AB

    Legit post. Well said.

    • Shay

      I crossfit 5 days per week and have always been told to avoid starchy veggies completely. Only allowed to have a sweet potato/yam maybe 3 times per month! I follow Paleo 80-90 % of the time and always have a whey protein shake post work-out. Now reading this post has definitely made me think. What are some other options other than a yam? Or would it be okay to consume a yam post work-out everyday and still lose fat? I have no problem eating eggs or egg whites (I do everyday) and love yams but thought I was supposed to avoid them (in excess)! How much of the yam should I have PWO, maybe a quarter of it? Thank you so much for any response :)

      • http://www.thelazycaveman.com The Lazy Caveman

        Crossfitting 5 days a week is a ton of work! You are at serious risk of burning out your adrenals due to overproduction of cortisol. High cortisol is a survival mechanism that prevents you from losing fat because your body starts to believe that it needs those fat stores to survive. So by eating a good source of glucose post-workout, you prevent the additional cortisol rise (beyond what comes from exercise) that would come from increased gluconeogenesis.

        Start with the equivalent of a fist full of sweet potato (or yam, taro, cassava, tapioca, butternut squash, etc.) and see how that affects you. Listen to your body; if it wants more than that, give it more. I highly recommend this article by Scotty Hagnas "The Case for Higher-Carb Paleo Diets" that is especially relevant to CrossFitters: http://www.cathletics.com/zen/index.php?main_page… (yes it's about $3 but well worth it. Consider getting a full subscription to the Performance Menu, it's great).

        The toughest part is going to be mental. After eating low-carb Paleo for so long, it's really hard to get yourself to eat more carbs, but you will see a difference in your performance and the way you look!

        • Shay

          Thank you so much for your response! You're right it is definitely a mental hurdle however, I'm going to try it!

  • http://thatsgross.wordpress.com dgroseph

    TLC, for the too naive to think, and possibly not paying attention all the time, can you tell us about your favorite lean proteins and starchy carbs? If that's too easy, can you tell us about ones that fit in a gym bag, can be at room temperature all day, and can be eaten while driving?

    • http://whole9life.com Dallas @ Whole9

      I'll let The Lazy Caveman address your question directly, but why does your PWO meal have to be at room temperature all day and be eaten when driving? I suggest a small cooler for your food if a fridge is not available, and shoot, if you can't take 5-10 minutes to eat your PWO meal without driving while doing so, you might need to re-evaluate how insanely busy your life is, considering that the stress of living a life at that fast of a pace will probably undermine any health/fitness benefits of training anyway. Just a thought (intended to be helpful, not spiteful).

      • http://thatsgross.wordpress.com dgroseph

        Dallas @ Whole9, I really appreciate your thoughts. While I do not live my life at exactly the pace I described, it's not far from it. And since a lot of people do live that way, and you can't change your life in a day, I figured it'd be great to pose this harder (more constrained) question :-)

        As for your suggestions, a cooler is a great idea (I take a small lunchbox with me on the train that probably should be a bit bigger a bit cooler). As for not having to drive while eating, I'll second that a pace like that can be stressful, but there are always trades that people have to make, as I'm sure that you and TLC are both familiar with, that take time to enact. Whether it's changing jobs to allow your thoughts and actions to fall in line with your values, or committing to a longer commute in order to live closer to family, big changes like that can't happen overnight, so in the interim, busy people still want to eat well!

    • http://www.thelazycaveman.com The Lazy Caveman

      Yams are by far my personal favorite starchy carb. And I prefer eggs fried in coconut oil for my protein. Tuna pouches would be a good way to go for something that can stay room temperature. Homemade, sugar-free jerky (or some from the likes of Steve's Paleo and other grass-fed jerky makers) are good choices. If you can't do fresh, look for proteins that are vacuum-sealed or canned until you're ready to eat them.

      • http://thatsgross.wordpress.com dgroseph

        Once we settle into our new kitchen I'm _definitely_ going to be looking into some jerky experiments. Until then, I'll also play with preparing some yams / sardines for PWO eating between soccer and driving home. Thanks for the tip!

  • pwli

    Hey! would like to clarify if the re-feed is suitable even if I am on a fat loss quest? thanks!

    • http://www.thelazycaveman.com The Lazy Caveman

      If you are engaging in intense exercise of any kind, post-workout is a vital part of fat loss for a couple of reasons:
      - Protein is key for muscle repair and growth
      - Insulin sensitivity is high post-workout, so it takes less insulin to move the same amount of nutrients. When we ingest excess carbohydrates outside of this window (when insulin sensitivity is normal), there is a higher likelihood that insulin will convert those carbohydrates to fat, since we can only store a small amount of carbohydrates as energy.

      Now if you're not doing intense exercise and are instead doing some light weightlifting sessions or walking, then your post-workout meal can be fairly small. Remember, we shouldn't be exercising to lose fat, but to gain muscle and increase work capacity.

      Oh, and be careful using the term "re-feed"; that usually refers to carb refeeds and means a totally different thing.

  • PW

    Hey TLC! What would you recommend for someone that is starting a oly program with some light met-con mixed in maybe once or twice a week? I remember reading on Catalyst that there is no real demand on the glycolytic pathway for weightlifters so glycogen reloading is not necessary. Thanks!

    • http://www.thelazycaveman.com The Lazy Caveman

      I'd still recommend that you eat a good post-workout meal focused on real food, but because you're not going much glycolitic work, there doesn't need to be too much of an emphasis on starchy carbs. Some protein, leafy carbs and a bit of fat will do you just fine, and still provide your body with the nutrients it needs to build muscle.

  • Pingback: Paleo explained - avoiding some foods | The Paleo Recipe Book Review

  • Anonymous

    Oh boy, these two articles wore out my liver glycogen.

  • Series4gt

    Post workout window is ver crucial to shuttle in carbs and spike insulin if u don’t get the right combination of carbs and protein you can be insulin resistant for up to 72 hours. Me personally I take 40g of dextrose with my protein

    • Anonymous

      Insulin spiking isn’t helpful to long-term health. The reason that we fuel after a workout in the first place is to take advantage of both non-insulin mediated transport and increased insulin sensitivity (exercise makes you more insulin sensitive, not more insulin resistant). Dextrose definitely does work for replenishing glycogen, but it doesn’t come from real food and I’m not convinced there are no detrimental side effects to health long-term.

  • Pingback: 6 Features of CrossFit | Barefoot Coconut

  • Pingback: Who Inspires You? | Barefoot Coconut

  • Pingback: What The Hell Is Paleo? | Go Fab Get Fit

  • Ryanmadi

    Ok so I do crossfit 2 times a day, 5 days a week with a lot of swimming and oly lifting mixed in between. I have been training for the SEALs like that for a couple years now. What should I do for a post workout recovery? Food is not always an option, I go to a military academy and we get fed what is basically prison food, in small portions with sleep deprivation also being an issue. If there is a supplement out there, which one do you recommend, and any other advice would be much obliged. Thanks

    • TheLazyCaveman

      Hi Ryan,
      While real food is always preferable, since you’re trying to do super human things, you may need to use super human supplements that go beyond real food. For post-workout protein, a good whey like those from SFH would be great. For glycogen replenishment, a product like GENR8 Vitargo would be fine. Thank you for your service and good luck with training!

  • http://www.facebook.com/people/David-Pugh/1321640221 David Pugh

    What would be a good pre workout meal to have?

    • TheLazyCaveman

      A little bit of protein and some carbs seem to do the best for me. It should be something easy to digest, that won’t come back up when you workout hard. You’ll have to experiment with what works best for you, but personally, I like a little bit of deli meat and some fruit.