This article is the fourth installment in our nutrition series.
In part one we talked about the basics of nutrition including what exactly micro and macro nutrients are and what role they serve in the body.
In part two we covered how the body turns food into cellular fuel.
In part three we discuss how the body manages energy levels throughout the day
In the past three articles we’ve laid a lot of groundwork to build our understanding of how the human body turns the food we eat into fuel. With this understanding, it’s time to turn our attention to what exactly we should be eating both pre and post workout to ensure we are giving our body what it needs to be successful. It’s important to note that CrossFit athletes train in a specific manner and our requirements are going to be different from those of others, notably endurance athletes. So, be aware that the following recommendations are for those specifically looking to excel in high intensity / CrossFit style training.
In a previous article, I detailed our training philosophy here at Cigar City CrossFit. In that I talked about the three primary metabolic pathways of the body and how CrossFit looks to train all three. I’m going to give a brief overview again, but for those interested, check out the full article here.
For your body to function you need energy. The cells in our body are powered by ATP (adenosine triphosphate) which is created by the cell's mitochondria. Based on the intensity level of the exercise our bodies will use one primary energy pathway.
These “metabolic engines” are known as the phosphagen pathway, the glycolytic pathway, and the oxidative pathway. The first, the phosphagen, dominates the highest-powered activities, those that last less than about ten seconds. The second pathway, the glycolytic, dominates moderate-powered activities, those that last up to several minutes. The third pathway, the oxidative, dominates low-powered activities, those that last in excess of several minutes.
Now, the majority of our workouts will use both the anaerobic and aerobic pathways, however, the primary energy system will be the glycolytic system. As this process is anaerobic, the primary fuel source is glycogen stored within our muscles. As you’ll recall from our previous articles, glycogen is the stored form of glucose, which we obtain from eating carbohydrates.
So, for high intensity training we need to ensure our muscle glycogen stores are maxed out. If you have ever felt flat during a workout or everything you lifted felt heavy, more than likely your glycogen levels were low. As a result, your body is lacking in quick energy and has to go through the longer process of aerobic glycolysis where stored fats are broken down to fatty acids to fuel your body. In CrossFit, where intensity is king, carbohydrates are your friend.
Everybody’s digestion is unique and some foods sit well with some and not with others. Our primary goal with our pre workout meal is first to ensure our muscle glycogen is maxed out and second to ensure we feel light and nausea free.
Within 90-120 minutes before working out, the best foods to eat are simple carbohydrates that will digest quickly. We always advise whole foods over supplements. To this extent, fruits are your best friend in pre workout situations. All fruits are great options and should not be limited. However, as you get within 60 minutes of your workout time, look for fruits with less fiber. These include melons like watermelon, honeydew and cantaloupe as well as ripe bananas. Dried fruit, not sweetened with sugar, is another great option. Dried fruits have a higher glycemic index than fresh fruits because their water has been stripped which concentrates their sugars.
To help satiety and to ensure adequate amino acid supply, it’s good to mix your pre workout meal with protein as well. While we advocate whole foods, it’s best to consume a powder protein during your pre workout meal as it will absorb faster and won’t upset your stomach.
When we talk about absorption rate, it’s important to note that we’re not talking about how quickly the protein hits your bloodstream. What actually matters is how quickly amino acid synthesis in the bloodstream occurs.
If possible, look to consume a liquid meal of fruit and protein. Blending the fruit will break down its fiber and speed its absorption. So, putting it all together, an ideal pre workout meal occurs within 90-120 minutes before your workout and looks like:
It’s also important to note that fat intake should be kept low during your pre workout meal as fat will slow down overall macronutrient absorption and feel heavy in the stomach.
After training, your body is depleted. Muscle glycogen and electrolytes are depleted. Additionally, you’ve just stressed your muscles, creating micro-tears to your myofibrils (muscle tissue). The goal of post workout nutrition is to replace what you’ve lost and allow your body to adapt, i.e. get stronger.
It’s important to note that there is conflicting research on this topic, but the following denotes the general consensus.
Any casual internet search on post workout nutrition will speak of a window of gains, 15-30 minutes post workout where your body is primed to accept nutrients.
To be clear, this window is real. The following excerpt is from a meta analysis of the data from a research paper titled: Nutrient Timing Revisited: is there a post exercise anabolic window?
Studies show a supercompensation of glycogen stores when carbohydrate is consumed immediately post-exercise, and delaying consumption by just 2 hours attenuates the rate of muscle glycogen re-synthesis by as much as 50%. Exercise enhances insulin-stimulated glucose uptake following a workout with a strong correlation noted between the amount of uptake and the magnitude of glycogen utilization. This is in part due to an increase in the translocation of GLUT4 during glycogen depletion thereby facilitating entry of glucose into the cell. In addition, there is an exercise-induced increase in the activity of glycogen synthase—the principal enzyme involved in promoting glycogen storage. The combination of these factors facilitates the rapid uptake of glucose following an exercise bout, allowing glycogen to be replenished at an accelerated rate.
Additionally, insulin helps with protein synthesis, so consuming carbohydrates with protein post workout will expedite the recovery process. However, there is more to the story. The researchers found that given a long enough period and assuming proper macronutrient intake (read: you eat enough calories of the right stuff) your body will replenish its glycogen stores and muscle growth development will occur at the same rate. Said differently, if you eat enough calories and consume the appropriate amount of protein throughout the day, you will not limit your potential gains.
This may sound like conflicting ideas, but the crucial part to understand is the timing factor. If you are in a competition where you will need to compete again within a few hours, then consuming a carbohydrate and protein rich meal post workout within 30 minutes is absolutely crucial. But, if you are like most of the training population, where you only workout once per day, the necessity to expedite the recovery process becomes a moot point.
So, what are good food options post workout? It depends on what time table you’re working with. If you’re in competition and need to compete again, you’ll want fast digesting carbs and protein. A shake with fruit and protein blended together is ideal. If timing isn’t a mandate, you’ve got more options. Most athletes head home after a workout. Eat a starchy, protein filled meal. Eat whole foods like potatoes, spinach, legumes and salmon.
It’s important to note that eating right after you workout is a great habit to get into. You’ll get the added benefit of speeding up your recovery and it will jumpstart your metabolism. The latter point is important because the biggest factor in proper recovery and adaptation is eating enough good calories.
Carbohydrates and protein are your friends pre and post workout. Focus on whole foods, especially fruits. Stay away from fats during this period as they tend to make athletes feel nauseous, slow digestion and require substantial energy from your body to breakdown.