The Protein Paradigm in Endurance Sports

Protein is such a hot topic right now online. You have many influencers telling people to eat up to 1-2 grams per pound of body weight. But do these people really know what they are talking about? And what is appropriate for an endurance athlete? Do endurance athletes really need to focus on protein? What sources are the best? These are all questions I hope to answer with this podcast. Of course, if you prefer to listen to a podcast on this topic, you are in luck. Justin from Tabula Rasa Racing and I discuss this very topic on our podcast. If you want to check out the podcast, you can go to this link: https://theenduranceathletejourney.buzzsprout.com/

Let’s start with the basics

What is protein and where do we get protein? 

I am not going to go into a crazy amount of detail here, but it is important to know what protein is and why it is important. Proteins are made up of amino acids. Think of it as if the amino acids are Lego pieces and these Lego pieces are all connected together to create a shape or form. When we eat protein foods, the digestive enzymes digest or break apart the protein back into the individual amino acids, which are then absorbed.

What are the 9 essential amino acids and why is this important? There are actually 20 amino acids found in the human body, but closer to 500 amino acids are found in nature. Within those 20 amino acids found in the human body, there are 9 essential amino acids. This means that we must eat protein foods in order to get enough of these amino acids, and they can't be synthesized by the body. The 9 essential amino acids are histidine, isoleucine, leucine, valine, lysine, methionine, phenylalanine, threonine, and tryptophan. There are some conditionally essential amino acids as well, and this just means that there are some specific conditions in which the body may not be able to produce these amino acids, and we would need to get them through food. This includes arginine and glutamine.

Why do we need protein? Proteins or amino acids are present in almost every cell and structure of our body, including bones and skin. We most commonly think of protein as muscle, but protein is so much more than that. Without protein, we would eventually die because our body would not be able to maintain vital structures such as heart muscles. Protein is important for muscle health and maintaining muscle mass, which is crucial as we age and is also very important for athletes.

What happens if we get too much protein? When we eat too much protein or more protein than our body needs in a day, we can't really store it. There is some ability to store small amounts, but it is not like carbs, where we can store them as glycogen, or fat, where we can store fat in fat cells. Therefore, we do need to get adequate protein on a daily basis to ensure we are meeting our needs for this nutrient. When we eat more than what we need, our body can't store that in muscle. If we could store additional protein as muscle, it would be very easy to overeat protein and build a large amount of muscle mass. This is not the case. So our body can actually utilize protein for fuel. This process is not super efficient, but it is possible to use certain amino acids and create glucose in a process called gluconeogenesis. Protein is a very satiating nutrient, which means it helps us feel full and satisfied, and many people struggle with getting enough protein rather than eating too much. When people eat too much protein, they might have digestive issues such as increased flatulence, constipation, or abdominal discomfort. Excessive amounts of protein over a period of time could be linked to kidney issues or increased urination. Excessive consumption of animal-based protein could also contribute to heart disease. However, over-consuming protein on occasion won't lead to these issues, and in most cases, eating slightly more than we need just means our body will use that additional protein as fuel.

What happens when we don't get enough protein? I already hinted at this when I discussed why we need protein, but not getting enough can be problematic because protein is so critical to so many structural components of our body, from our bones to muscles to our hair and nails. Without enough protein, our body will first start to break down muscle to provide protein to vital organs, and once we deplete muscle, the body will start to break down protein in tissues like the heart. The good news is that most people have enough stored protein to last for several days. There are cases in which people can fast for days or even months, but the body can also rely on fat for fuel, so this helps spare the protein being broken down for fuel. Instead, the body spares the protein and utilizes mostly fat instead.

Protein's Importance for Endurance Sports

Many people think of protein as an important nutrient for bodybuilding or building muscle. The emphasis for endurance sports has always been on carbohydrates. However, as many endurance athletes are starting to realize, it is hard to perform optimally without also being strong. There is a surge in hybrid athletes and muscular runners and triathletes. The emphasis on power-to-weight is also important. This all means that muscle does matter when it comes to endurance sports, and the only way to maintain or build muscle is to make sure you are consuming enough protein.

During long-duration exercise, we can also break down more protein in muscle. This protein can be used as fuel, but we also accrue muscle damage during endurance exercise due to the stress of the exercise on the muscle tissue. This means that endurance athletes may actually need more or similar amounts of protein compared to athletes competing in more power-based sports or bodybuilding. We need to be supplying enough protein to repair damaged muscle and resupply protein that has been used for fuel during exercise.

Why is there confusion about protein?

There are a few different camps when it comes to protein. There are the fitness influencers claiming that we all need to eat 1-2 grams per pound, or there are the people out there claiming that protein causes cancer and we need to limit it as much as possible. Neither of these recommendations is appropriate for athletes. So don't let the scare tactics get in your head. No, eating protein does not cause cancer because it can increase mTOR (a protein that helps control cell function, including cell growth and proliferation), but there are so many things regulating cell growth and proliferation. There are more serious consequences to not eating enough protein, especially as we age and the risk for muscle loss accelerates.

Basic info on protein intake and what is enough for endurance athletes

The recommended dietary allowance is 0.8 g/kg for adults or approximately 0.4 grams per pound. This is not enough! This is the basic need for a person who is not active just to survive. There is an abundant amount of research that suggests this is not enough, and this is especially not enough for athletes.

The problem is that it is hard for me to write an article that provides recommendations to the general endurance athlete community because each of us is a bit individual. The amount may depend on if you are training for a long endurance race vs. a 5k, or if you are also lifting weights, or if you want to lose weight. It may also depend on what types of protein you are consuming. My vegan athletes need to consume more protein to ensure they are getting enough of all the essential amino acids. So I am giving some general guidance, and if you have questions, I recommend working with a sports dietitian to figure out what is best for you.

In general, 1.2-1.5 grams per kilogram of body weight is a good goal. That is about 0.6-0.7 grams per pound. Honestly, going up to 0.8 or even 1 gram per pound might be okay in some circumstances. If someone is on the heavier side, they can also estimate their protein needs based on adjusted or ideal body weight. You can find an adjusted body weight calculator here.

The types of protein and how to get enough

Does the protein source matter? 

This is a bit more controversial of a topic because there is so much nutrition dogma out there when it comes to plant-based versus carnivore or animal-based protein. I don't subscribe to a diet or lifestyle, so I am not coming at this with anything but the research in mind. If you are vegan because you love animals or for some other reason, I totally understand. Just know that being a vegan or vegetarian athlete might require a little more planning and thought because you do have to be mindful of getting all of the essential amino acids. If you are trying to be an endurance athlete on the carnivore diet, all I have to say to you is good luck. For everyone else out there trying to figure this out, there really is no advantage to eating only plant protein. In fact, animal-based sources of protein are complete proteins and contain all of the essential amino acids and all sorts of other great nutrients that athletes need, such as vitamin B12 and iron. It is also just easier to meet your protein needs when consuming animal-based proteins.

Of course, many animal-based proteins also have saturated fat, which can increase heart disease risk for some people. Keep in mind that so much of the research is correlational when it comes to heart disease risk or other potential risks like colorectal cancer. This really depends on the quality of animal-based protein (maybe limit your intake of processed meats) and how much fat is contained in the protein. It also depends on other lifestyle factors like fruit/veggie intake. So what do you do as an endurance athlete? If you are not deciding to be vegan or keto or carnivore for some specific reason, it all comes down to balance. Having a balanced approach to protein is a great idea. I personally love all sorts of protein sources, including tofu, fish, meat, dairy, beans and lentils, nuts/seeds, and even the occasional plant-based burger. If you are willing to incorporate more plant-based dishes into your routine, you may find that you really like the variety, and it can help minimize the risk for things like heart disease. We do know that the more fiber you can consume, the better off you are in terms of developing diseases like heart disease, so make sure that whatever types of proteins you are consuming, you are also eating a diet rich in fruits, vegetables, whole grains, legumes, and nuts and seeds.

What are protein sources? Here is a quick overview of sources that contain the most protein:

• Fish/seafood - All fish is good for protein, but make sure to consume more fatty fish such as sardines, mackerel, anchovies, salmon, and herring, which are rich in heart-healthy fats. Shellfish such as oysters, clams, and shrimp are very nutrient-dense. Fatty fish contain omega-3 fats, which can actually be protective against heart disease.

• Eggs, but if you are able to find pasture-raised eggs, that is even better.

• Red meat, lamb, and pork are good sources of protein, vitamin B12, zinc, and iron, but if you are able to afford grass-fed red meat, that is even better.

• Unsweetened Greek yogurt, cottage cheese

• Poultry such as chicken, turkey, and duck

• Unsweetened, plain protein powders such as whey, pea, and collagen

• Vegetarian sources such as tofu, tempeh, and seitan

• Legumes such as beans, lentils, and peas. These protein sources are also high in carbohydrates, so that is something to keep in mind.

Is there optimal timing of protein? Spreading it out vs. eating a bunch all at once - what is the evidence? 

There is also some controversy in terms of when to eat protein. There is a big fad that may or may not still be popular where people only eat one meal a day, also known as the OMAD diet. If you are an endurance athlete, please don't do this. It is a recipe for disaster in terms of performance, not to mention how badly this can wreak havoc on your glucose values if you happen to be using a CGM. In terms of a protein perspective, as long as you are getting enough, it does not seem to matter as much in terms of when you eat it. However, I am not in the business of just kind of doing what barely works; I am in the business of helping people optimize. So based on the research and my own experience working with athletes, I tend to recommend spreading the protein intake out into 3 meals and 1-2 snacks. So if someone is needing 120 grams of protein per day, I would recommend 3 meals with about 30 grams of protein and at least one high-protein snack of around 20-30 grams of protein. This helps athletes ensure they are getting enough protein, and it also optimizes their chances of being able to utilize that protein for things like muscle repair and muscle growth.

Now, you don't need to be drinking that protein drink the moment you leave the gym (or trail or track) after a long workout. In fact, after a hard effort, it makes more sense to prioritize carbohydrate intake to take advantage of increased insulin sensitivity and optimizing glycogen storage. I do recommend trying to get a good amount of high-quality protein within 2 hours post-exercise. If you want to consume both the protein and carbs immediately post-exercise, that is obviously a great choice. It may come down to timing of meals and snacks around the workout, or if you are traveling to a trail, for instance, you can have something that is easier to consume immediately post-workout (such as a bagel, banana, or bar) and then eat a solid meal with both protein and carbs when you get home.

Practical ideas for getting enough protein for athletes

• Protein powders are okay but don’t contain other nutrients (micronutrients or fiber) unless added.

• Protein bars, protein drinks, and protein snacks are also okay for on-the-go situations or really busy days.

• Meal prep/meal planning is important—consider making bulk protein options such as a large batch of baked tofu, a crockpot of shredded chicken, or cooking a few pounds of lean ground beef so you have some protein on hand to add to meals when you are busy.

• Things like cottage cheese, string cheese, hard-boiled eggs, Greek yogurt, edamame, and air-fried tofu are all great choices.

Make a bunch of hard-boiled eggs for the week to have on hand for quick protein add-ins or for a high-protein snack.

I think I covered all of the basics when it comes to protein. I know a lot of this is simple, but isn't that how it should be? I am so over all of these fitness influencers on Instagram pushing unrealistic expectations about nutrition and people on YouTube with fear-mongering messages about eating too much protein or animal-based protein. It is not really that complicated. If you need more help determining your individual protein needs or want an individualized meal plan or meal ideas to help provide some guidance, please reach out!