Part 1: Understanding The Role Of Pre-Workout Carbohydrates
Building muscle is a science. It’s deeply rooted in nutritional science, which can admittedly, be overwhelming. This confusion can be mitigated by tying in application to the abstraction of nutrient chemistry. By using your body as the mechanism for this action, the science will start to become clearer. As you read through this, try to visualize how this information can directly benefit you and help you achieve your goals. Your primary objective is to think critically about this material – the purpose is to understand it, not simply follow this plan as a surefire blueprint to your unique goals.
Why Start Here?
Your workout acta as a catalyst for establishing a window of opportunity, creating the potential for muscle growth. As such, when developing your own diet plan, the nutrition around your workout should be given priority. Establishing a favorable hormonal environment for muscle growth starts with the meal consumed prior to training. This meal, and the subsequent nutrient recommendations during and post-workout will greatly influence the potential for, and the rate of, muscle protein synthesis.
Pre-workout nutrition has always been a fascinating topic, and it’s been discussed at length in the fitness world. The crucial understanding of key variables should lay the groundwork for pre-workout nutrient considerations. The (deceptively) simple question, “what is trying to be accomplished and how can it be influenced?” needs to be investigated thoroughly. Your goals should take into account every possible known variable that may affect the determinants of the muscle protein synthesis pathways. The pre-workout nutrition thought process should be focused around achieving the best and most productive workouts possible.
While we want to supply the body with fuel for the workout, we have to be careful on how we define what this is. Carbohydrate intake is the largest variable for this meal and its hormonal effects must be investigated.
• The goal of a pre-workout meal should be to put our bodies in a favorable hormonal environment to reap as many benefits as possible from our workout.
• Insulin suppresses growth hormone, so our carbohydrates should be limited and come from low-glycemic sources.
• Protein can cause rises in insulin, so caution must be taken when choosing a protein source.
• The pre-workout meal should be consumed 90 minutes prior to training.
A Quick Disclaimer
There’s plenty of ways to go about programming a diet plan and this is, by no means, the only way to do it. I encourage you to, rather than blindly following these recommendations, think critically about what’s trying to be achieved. Your goals may be different or may change and as such, so would your diet strategy. By understanding specific key mechanisms however, you’ll be able to adapt quickly, adjusting your diet as needed.
This diet strategy (and I’d argue, all diet strategies should) has a holistic philosophy to it – that is, the pre-, intra-, and post-workout meals are designed to compliment one another. The pre-workout guidelines outlined here may not be optimal standing alone. As I continue to post in this blog series, be sure to come back and reread each part to ensure complete understanding.
Carbohydrates and Growth Hormone
Growth hormone (GH) has a vast array of benefits that we certainly want to take full advantage of. Ensuring optimal GH output prior to training is one of the first steps towards producing a favorable hormonal environment conducive to muscle growth.
• Adipocytes (fat cells) have GH binding sites. When GH binds to these receptor sites, it causes them to break down. Furthermore, the ability of these adipocytes to take up circulating fat in the bloodstream diminishes.
• GH stimulates protein anabolism in many tissues. It increases amino acid uptake and decreases the breakdown of proteins.
• GH has blood glucose regulating properties.
When GH levels are high, more muscle and less fat will be present. How does this tie in with the pre-workout meal? Well, elevated insulin levels have a physiologic inhibitory effect on GH release (Lanzi, 1999; Ji, 1999) It’s important that elevated insulin is avoided prior to training. Low glycemic carbohydrates, eaten roughly 90-120 minutes prior to training (sometimes even more) should ameliorate this. You may ask why even include carbohydrates in this meal? Wouldn’t it mean more GH production if we went zero carb? Well, possibly. It’s a common strategy, but it’s best reserved for someone who’s body fat percentage is relatively high and whose goal is primarily fat loss. To build muscle and increase performance, carbohydrates are needed. Muscle protein synthesis appears to increase significantly with a combination of protein and carbohydrate within close proximity to the workout (Kerksick, 2008). In short, the consumption of carbohydrates should be high enough to support the training session, yet minimal so as not to suppress growth hormone.
A Neurotransmitter Balance
Prior to discussing neurotransmitters and their effects, it must first be emphasized how important intense and productive training sessions must be. Muscle protein synthesis, induced by the downstream phosphorylation cascade of the mTORC1 (discussed later), sees more stimulation with more muscular activation. Put plainly, more (and more efficient) muscular contraction results in a greater potential for muscle protein synthesis. It’s not so much about the set and rep scheme as it is execution. One’s mentality when entering the gym is rarely discussed in a nutrition plan yet is such an important variable which should, at the very least, be acknowledged. Drive, motivation, and even motor control can be greatly influenced by the pre-workout meal.
Tryptophan, an amino acid, is promoted during bouts of exercise under low carbohydate (and the subsequent absence of insulin) conditions. This elevation may prove to be troublesome prior to intense resistance exercise. The distinction of type of exercise is important – tryptophan production has demonstrated a potential to increase endurance capacity and increase pain tolerance. These beneficial effects would be useful for someone like a long-distance runner – probably not suitable for the type of workout needed to pack on muscle.Moreover, there seems to be a threshold in which tryptophan levels should not exceed. Surpassing this point may be a large contributing factor to central fatigue – a topic I’ll discuss in the near future. This may be due, in part, to increased levels of serotonin – a neurotransmitter you have probably heard of. It’s reputation (and maybe unjustly) is often associated with the sleepy feeling after a large meal with Thanksgiving turkey somehow becoming the main culprit. Furthermore, low levels of insulin prior to training favors tyrosine uptake over tryptophan. Tyrosine, in contrast with tryptophan, is something that favors the type of exercise necessary to stimulate maximal muscle protein synthesis rates. Tyrosine is a precursor to dopamine, a neurotransmitter involved in motor function and mood. Dopamine lends a hand to the central nervous system, allowing it to fire proficiently. Intuitively, it stands to reason that this would translate to greater strength increases. While more research on the matter is warranted, the mechanisms of action of dopamine are soundly defined.
It should start becoming clear that there is a small range of carbohydrate intake that promotes the effects we’re looking for: high growth hormone production, more efficient tyrosine uptake, and controlled levels of tryptophan. Reinforcing my point earlier, the goal of pre-workout carbohydrate ingestion should be to consume the least amount possible whilst still providing the means for the benefits mentioned.
Types and Amounts of Carbohydrates
So, I think the goal of the pre-workout meal has been clearly established, wouldn’t you agree? Our goal (at least in this context) is to create a favorable hormonal environment for muscle growth. The amount of low glycemic carbohydrates must now be defined. As you’ll see in the next installment of this blog series, intra-workout nutrition will be a valuable strategy that will be employed – this will further strengthen the argument for low carbohydrate intake pre-training. Since everyone is different, this number will fall into a range. 20-35 grams of low glycemic carbohydrates, 90-120 minutes prior to training is recommended as a starting point. It may be tempting to want to increase this number to “get a better pump” or to “fill out” but I urge you to make adjustments slowly – remember, we want to use the least amount possible. Over time, this number will likely increase. This will depend on your size, training intensity, consistency, and rate of growth. But it’s actually quite eye-opening to see just how little carbohydrates you need pre-workout (intra- and post-workout are different matters) to see results.
Intra- and post-workout carbohydrate intake typically take priority when diet adjustments are to be made. The pre-workout meal should not need to change until post-workout nutrition and then, intra-workout nutrition, have been maximized. That is, increased to the point where no greater benefit can be achieved.
Controlling variables ultimately comes from simplicity – thus, I recommend only brown rice, sweet potato, oats, and cream of rice being used for pre-workout when starting. After several weeks, I’ll typically broaden a client’s food list to keep things from becoming too mundane. Unless there is a food intolerance or allergy present, these foods, due to their glycemic response, meet the aforementioned criteria for creating a suitable hormonal environment and neurotransmitter balance necessary for a productive training session.
A Note on Cream of Rice
Cream of rice is probably my favorite carbohydrate source because of its versatility. It can be made to be either sweet or savory which helps keep the diet interesting. In fact, your diet never has to be boring – it just requires a little bit of creative effort in the kitchen.
Cream of rice is also notoriously hard to find. If you are having trouble finding it, check this link. It’s the only way I order it myself as it’s a rare find at most grocery stores.
Ji, S., Guan, R., Frank, S. J., & Messina, J. L. (1999). Insulin Inhibits Growth Hormone Signaling via the Growth Hormone Receptor/JAK2/STAT5B Pathway. Journal of Biological Chemistry,274(19), 13434-13442. doi:10.1074/jbc.274.19.13434
Kerksick, C., Harvey, T., Stout, J., Campbell, B., Wilborn, C., Kreider, R., . . . Antonio, J. (2008). Erratum to: International Society of Sports Nutrition position stand: Nutrient timing. Journal of the International Society of Sports Nutrition,5(1). doi:10.1186/1550-2783-5-18
Lanzi, R., Luzi, L., Caumo, A., Andreotti, A. C., Manzoni, M. F., Malighetti, M. E., . . . Pontiroli, A. E. (1999). Elevated insulin levels contribute to the reduced growth hormone (GH) response to GH-releasing hormone in obese subjects. Metabolism,48(9), 1152-1156. doi:10.1016/s0026-0495(99)90130-0