Post-Workout Carbohydrates: Why They Aren’t Necessary

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Before you drown yourself in the latest sugar-laden post-workout concoction, ask yourself why?

A few years ago, I wrote an article on elitefts™ about the different ways to alter your peri-workout nutrition. From fasted training to intra-workout carbohydrates to limiting carbohydrates post-workout, it stirred up a little controversy. I didn’t specifically say that one was better than the other. Instead, I gave people ideas on how to incorporate all of them into their routines. However, I forgot that in the fitness industry, you have to make sure people know that your way is the only way and everything else surely has to be wrong.

If you’ve been lifting as long as I have, you’ve heard countless times that you need some fast acting carbohydrate source post-workout. Guess what? You were also told that you needed to eat every two to three hours to spike your metabolism and that there was a magical 30-minute anabolic window and that a fat-free diet would solve our heart disease epidemic. Point being, you’re told a lot of things that are simply outdated, overstated or just regurgitated so often that they couldn’t possibly be wrong. Well, here’s another to add to the list—carbohydrates post-workout are a necessity. Not so fast…

Before you scroll down and start telling me how much of an idiot I am, please understand that I’m not rendering post-workout carbohydrates as useless. In my opinion, there can be value in having them post-workout and restricting them post-workout. So why not explore that? Let me go back to the drawing board and see if I can help clarify some things. What does it mean to need something? A necessity is something that is required or indispensable.

Supplement companies have done a pretty good job of marketing their products toward our perceived “needs” as a lifter. Remember when creatine needed a ton of sugar to “work” (thanks, Celltech)? So, why do we need carbohydrates post-workout again? The main arguments are:

  • To initiate protein synthesis
  • To refill glycogen

I must have forgotten that lifting weights was all about rushing to see who refilled their glycogen stores faster. Now I’ll address both points.

The first myth stems from how anabolism actually leads to new muscle. If you ask most people, even those entrenched in the health industry, they believe that you need protein and carbohydrates to initiate protein synthesis. After all, muscle tissue growth will only occur if protein synthesis is greater than protein breakdown. The main driver in protein synthesis is amino acid availability, which is why “adding other nutrients like carbohydrates will not enhance muscle protein synthesis” (2, 3).

However, liked I’ve stated in the past, it is the presence of proteins and insulin that helps increase protein synthesis further. Carbohydrates are not the only thing that increases insulin levels. All foods stimulate the release of insulin to some degree, and things like leucine, arginine, and whey protein all do a great job of creating quite an insulin spike.

Aside from lowering the levels of glucose in the blood, insulin also suppresses protein breakdown (proteolysis). Because of this, it is often referred to as being anti-catabolic, even though it halts whole body protein breakdown and not just specifically muscle protein breakdown. Insulin will also work to build amino acids into new proteins, so it’s an essential part in your muscle building goals. The issue is that people use the terms carbohydrate and insulin as if they are synonymous. They are not.

But Fred, Vitargo, maltodextrin, blah, blah, blah. You know when these things are actually a necessity? When you pin insulin pre-workout and then need those carbohydrates so that you don’t die. So in that scenario, I would also agree that they’re necessary. Is your favorite guru letting you in on this secret or are you still living in a fantasy world? Injecting insulin is clearly going to change the game here, but unfortunately, for naive readers, this is left out. Back to stimulating insulin.carbohydrates post workout

Well, look what we have here. How dare these protein rich foods, including eggs, fish and beef, try and spike insulin (1)? Don’t they know that only carbs are allowed to do that? The best part is that leucine and protein powder both score higher in spiking insulin than the foods tested here. But that isn’t the point.

Still on the fence? Last time, I used this study by Koopman and colleagues where they tested three groups of males who underwent resistance training and then either consumed a protein only post-workout drink, protein and low carbs or protein and high carbs. They concluded that “co-ingestion of carbohydrate during recovery does not further stimulate post-exercise muscle protein synthesis when ample protein is ingested” (4)]. Here is an image of their findings:

no carbs post workout

The tables above compare whole body protein breakdown as well as protein synthesis, oxidation and net protein balance. While protein synthesis is slightly elevated in the protein and carb group, the net balance, which is arguably more important than synthesis alone, was higher in the protein only group. Net balance takes synthesis and degradation into account. It’s very interesting that protein breakdown was highest in the carbohydrate and protein group.

The criticism of the study was that the participants were untrained. This is the beautiful part about the internet. No studies used and you’re a moron. If you use studies, they have to be done on bodybuilders who are 250 pounds with abs and training seven days a week or else it’s garbage. Regardless, I believe this study helps illustrate that carbohydrates are not necessary in the post-workout environment.

Post-workout carbohydrate absolutists made sure to try and contradict my article but did a poor job in my opinion. “Well, Fred missed this study” or “The one study he used wasn’t on bodybuilders so this is useless.” Here’s a prime example. Someone asked me about this study: “Combined ingestion of protein and free leucine with carbohydrate increases post-exercise muscle protein synthesis in vivo in male subjects.” The title sounds cool, but let’s look at what is actually being tested.

It tested three groups—only carbohydrate, carbohydrate and protein and protein and carbohydrate and leucine. Let’s stop right there. How the hell is this study going to show how effective protein and leucine are alone compared to protein and carbohydrates? It isn’t. Of course, protein and carbohydrates will increase PWO protein synthesis. I never said that it wouldn’t. Protein-only will also increase PWO protein synthesis. Even in the fasted state post-workout, protein synthesis will still increase (as will protein breakdown).

Again, what you do over the course of the day will come into play. If you load up on carbohydrates pre-workout, you don’t need them immediately post-workout. If you train fasted or carb-less, carbohydrates post-workout make sense as full glycogen depletion could limit protein synthesis. Most weight workouts will not fully deplete stored glycogen, especially if the person is properly fueled up beforehand.

Wait, there’s more. In a recent commentary from the Journal of International Society of Sports Nutrition, the authors pose the question, “Is carbohydrate needed to further stimulate muscle protein synthesis/hypertrophy following resistance exercise?”

To spare you the torture of having to read a lot, here are some of the key points they discussed:

  • “It is true that insulin is needed to increase protein synthesis when amino acids delivery are increased. However, even very low levels of insulin are able to act in concert with leucine to enable protein synthesis” (5).
  • “Leucine ingestion has the ability to stimulate insulin secretion, and protein supplementation studies report a marked increase in circulating insulin concentrations at a minimum of two to threefold above fasting values” (5).
  • In regards to studies done on protein versus protein and carbohydrates post-workout, “these studies demonstrate that adding carbohydrate to a protein dose that alone is known to maximally stimulate protein synthesis has no additive or synergistic effect on muscle protein synthesis and breakdown” (5).

What about cortisol? This is a good example of people focusing on the most miniscule of things. In my opinion, the transient response of cortisol from exercise or not immediately slamming carbs isn’t of great importance for the majority of people. The research isn’t exactly sound in this area either. One study out of McMaster University actually found that high post-workout cortisol levels may be correlated with gains in lean body mass (6). Cortisol only becomes an issue when there are chronic elevations, in which case the person needs to seek advice from a medical professional.

The purpose of this article was to question conventional thinking in this area, not criticize post-workout carbohydrates. The goal of restricting carbohydrates post-workout is to maintain the insulin sensitivity gained from exercise and upregulate the usage of fat for energy. I think the research is pretty clear that protein synthesis won’t be compromised, especially if a large dose is accompanied by leucine just to cover all bases. Once again, I’m not saying that there is never a place for carbohydrates post-workout. I believe that you can alter the peri-workout window to favor your current nutritional goal.

Here are the take home points:

  • Post-workout carbohydrates aren’t necessary and they don’t further increase protein synthesis.
  • This doesn’t mean that you can’t use them in the PWO environment. If you train fasted or carb-less, they will be beneficial post-workout.
  • If you’re in a mass gain phase, post-workout is a nice place to try and increase carbohydrate intake.
  • If you’re an athlete who trains two times a day, it is necessary to refill glycogen stores so that you’re ready to compete again.
  • If you’re using intra-workout carbohydrates, there isn’t any need to rush for extra carbohydrates immediately post-workout.

References

  1. An insulin index of foods: The insulin demand generated by 1000-kJ portions of common foods. At: http://ajcn.nutrition.org/content/66/5/1264.full.pdf.
  2. Atherton PJ (2012) Muscle Protein synthesis in response to nutrition and exercise. The Journal of Physiology.
  3. Phillips BE (2012) Regulation of muscle protein synthesis in humans. Curr Opin Clin Nutr Metab Care.
  4. Koopman Rene, Beelen Milou (2007) Co-ingestion of carbohydrate with protein does not further augment post-exercise muscle protein synthesis. Am J Physiol Endocrinology Metabolism.
  5. Figueiredo Vandre, Cameron-Smith David (2013) Is carbohydrate needed to further stimulate muscle protein synthesis/hypertrophy following resistance exercise? The Journal of The International Society of Sports Nutrition.
  6. West DW (2012) Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. Eur J Appl Physiol.

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