Fueling the Distance: Why Protein Is Crucial for Runners

A deep dive into the science behind protein consumption for runners.

By on May 29, 2024 | Comments

[Editor’s Note: This article was written by guest contributor Lindsay Christensen. She is a nutritionist with a B.S. in Biomedical Science and an M.S. in Human Nutrition, and a Certified Nutrition Specialist (CNS) and Licensed Dietitian Nutritionist (LDN). She also has her own nutrition practice, Alpine Fuel Nutrition.]

If you’ve been a runner for any length of time, carbohydrates are probably like a childhood friend — you are intimately familiar with them, and having them in your life is second nature at this point. However, for many runners, protein is that new friend we were introduced to in adulthood — less familiar, and you’re still trying to get the hang of each other!

If you’re a runner who wants to stay strong, healthy, and run long into your golden years, protein is a friend you’ll want to make and keep. Together, optimal protein and carbohydrate intake will help you go the distance and enjoy a healthy running career.

There are several things to consider, including why protein matters for runners, daily protein requirements and timing considerations for optimal performance and recovery, and ways to incorporate protein into your daily nutrition plan.

Women running

Optimizing protein consumption can speed recovery after a workout, reduce muscle soreness, and maintain and create muscle mass. Photo: iRunFar/Eszter Horanyi

Why Does Protein Matter for Runners?

Proteins are a part of every cell and tissue in our bodies, including our muscles, bones, and signaling molecules within the immune system. Unlike carbohydrates, dietary proteins are not a significant energy source for the body. In other words, we don’t use them as a significant fuel source in daily life. However, as we discuss later, protein can become a more significant energy source during ultramarathons.

As runners, our bodies need dietary protein to repair and build muscle tissue. We also need protein to balance our blood sugar and support glycogen synthesis. Before discussing each of these functions, let’s first take a look at amino acids, the building blocks of protein.

A Primer on Protein and Amino Acids

When you eat protein, it is broken down in your gastrointestinal system into smaller building blocks called amino acids. Your body must acquire nine essential amino acids through your diet: Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Inadequate intake of even one of the essential amino acids can impair muscle protein synthesis (1).

Nonessential amino acids are those that our bodies can produce, usually from glucose or other amino acids. The nonessential amino acids include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.

Finally, there are also conditionally essential amino acids, which are usually not essential but become so during periods of stress or other physiological changes, such as illness or pregnancy. Interestingly, research suggests that some conditionally essential amino acids, like glutamine, may become essential in athletes due to high training loads (2).

Animal proteins — including meat, poultry, seafood, eggs, and dairy products — are considered complete proteins, meaning they provide all nine essential amino acids. Most plant proteins, with a few exceptions — such as soy — are incomplete proteins, meaning they do not provide all nine essential amino acids. This means that runners eating vegan and vegetarian diets must combine various protein sources, such as legumes and grains, daily to ensure an adequate intake of all of the essential amino acids.

Men running on trails

Adequate intake of all of the essential amino acids is important for muscle synthesis and recovery. Photo: iRunFar/Eszter Horanyi

The Benefits of Protein

Let’s review how protein consumption benefits overall health and athletic performance.

Muscle Protein Synthesis and Recovery

The body incorporates amino acids into skeletal muscle through muscle protein synthesis, allowing muscles to adapt to training. Insufficient protein intake can compromise muscle protein synthesis and may prolong recovery, and exacerbate delayed-onset muscle soreness (DOMS) (3, 4).

In my sports nutrition practice, I often meet runners who are under-eating protein. As soon as they optimize their protein intake to meet their bodies’ needs better, they often notice significant improvements in their recovery from training and muscle soreness.

Protein Balances Blood Sugar

Eating protein as part of balanced meals and snacks also helps balance blood sugar — the concentration of glucose in your blood that provides energy — by slowing down how quickly carbohydrates are broken down and absorbed in the gut. While you don’t want to slow carbohydrate absorption during a run, eating protein alongside carbohydrates in your daily meals can prevent large swings in blood sugar that sap your energy and, over time, possibly drive conditions like prediabetes.

Protein Consumed with Carbohydrates Aids Glycogen Replenishment

Glycogen is a stored form of carbohydrate. Most of it is stored in your muscles and liver where it can be broken down into glucose for energy during sleep, fasting, and physical activity. Replenishing glycogen after exercise is crucial for runners. Robust glycogen stores prolong endurance and may prevent bonking by acting as an energy reservoir that can replenish blood glucose levels. This can help preserve muscle tissue during prolonged exercise.

Men running on pavement

While protein consumption during a run generally isn’t recommended, eating it afterward can benefit recovery. Photo: iRunFar/Eszter Horanyi

How Much Protein Do Runners Need?

Recommended Dietary Allowances (RDA) are maintained by the Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine. This private organization establishes nutrition guidelines and recommendations for the U.S. population. An RDA is defined as a recommendation designed to meet the needs of the vast majority of healthy individuals.

The protein RDA is 0.8 grams of protein per kilogram body weight per day (g/kg/day). The consensus in the sports nutrition science community is that this RDA for protein is insufficient for meeting the protein needs of athletes, such as trail runners and ultrarunners. The RDA for protein is based on nitrogen balance studies, which estimate the minimum amount of protein needed to maintain essential physiological functions, not an amount that supports a high physical activity level and optimal health and performance.

Most researchers and sports nutritionists agree that runners need more protein than the RDA, but there is some disagreement about the “right” amount of protein for runners. Some experts have suggested an ideal protein intake range of 1.6 to 1.8 g/kg/day. For example, a 140-pound (64 kilograms) person should consume approximately 102 to 114 grams of protein daily (5, 6).

Other research on female athletes suggests a relatively higher protein intake of 1.4 to 2.2 g/kg/day is ideal (7).

Still, more research indicates that in ultrarunners looking to optimize performance and recovery during the peak of their training cycle, protein intake up to 2.5 g/kg/day may be warranted (8).

In other words, protein needs for runners are individualized and dependent on training volume, intensity, and other health needs. You’ll need to experiment a bit or work with a sports nutritionist or dietitian to find what works for you.

Women running on dirt road

Women can have differing protein needs depending on their age, hormone levels, and other factors. Photo: iRunFar/Eszter Horanyi

Special Considerations for Protein in Female Runners

The protein needs of female runners may be more complicated than those of male runners due to hormonal changes during premenopause, defined as the time of a female’s life during which menstruation occurs, and perimenopause, when the body begins to transition toward the cessation of menses.

The fluctuations in estrogen and progesterone that premenopausal women experience across their menstrual cycle may change their protein needs. During the second half of the menstrual cycle, the luteal phase, women’s bodies are more prone to protein breakdown after performing aerobic endurance exercise, such as running. This means women may need to eat more protein during the luteal phase of their cycle than during the follicular phase, the first half of their cycle (7).

For women in perimenopause, shifts in hormones can make it harder to maintain lean body mass. For this reason, perimenopausal and menopausal runners may benefit from a daily protein intake in the middle to higher range of recommendations — 1.4 to 2.2 g/kg/day (7).

What About Protein and Kidney Function?

These protein recommendations for runners may be a big jump in protein intake for some. This may raise the question of whether higher protein intakes harm the kidneys. The most current research shows that higher protein intakes do not harm people with healthy kidneys.

So, as long as you have healthy kidneys, you do not need to be concerned about bumping up your protein intake (6, 9).

Timing Protein Intake for Optimal Performance and Recovery

A basic rule of thumb is to eat a meal with a 2:1 to 1:1 ratio of carbohydrates to protein before most training runs. A pre-race meal should be on the relatively low side of protein consumption since a high-protein meal can trigger gastrointestinal distress. Before a race, a 3:1 ratio of carbohydrates to protein would be appropriate.

Eating a meal that provides protein and carbohydrates within 30 to 60 minutes of finishing your training session is also important to help initiate the muscle repair process. While post-run protein recommendations vary, most athletes do well eating between 20 to 40 grams of protein in a post-workout meal.

In your daily life, dietary protein isn’t utilized as a major energy source for the body. However, when running ultra distances, bodies begin to break down muscle protein for energy. Therefore, when you’re on the trail training for over three hours, eating some protein can prevent your body from breaking down muscle proteins for energy. Even a small amount of protein, around five to 10 grams per hour, should be helpful during training runs over three hours long (8). A whole food that contains protein, such as peanut butter spread inside a tortilla, or a sports nutrition product that contains essential amino acids are both options for supplying protein during long runs.

Lastly, athletes should try to distribute their total protein intake evenly across the day, eating some approximately every three to four hours. A relatively even protein distribution throughout the day may be most effective for supporting your training, recovery, and balanced blood sugar (6).


iRunFar’s Meghan Hicks eating a cheeseburger while walking toward the Mount Yale trailhead in Colorado during her then Nolan’s 14 fastest known time effort in 2016. Photo: iRunFar/Bryon Powell

Protein Sources for Trail Runners and Ultrarunners

It’s a good idea to include a variety of proteins in your diet. Protein can be found in foods coming from both animals and plants.

Here are examples showing the approximate amount of protein in standard servings of various foods:

  • 4 ounces (oz) of 90% lean/10% fat ground beef provides 23 grams
  • 4 oz of chicken breast provides 31 grams
  • 4 oz of salmon provides 28 grams
  • 1 egg provides 6 grams
  • 1 cup (c) of cooked chickpeas provides 14.5 grams
  • 1 c of cooked lentils provides 18 grams
  • 2 oz of tofu provides 6 grams
  • 1 c of tempeh provides 33 grams
  • 1/4 c of almonds provides 6 grams
  • 1 c of whole-milk Greek yogurt provides 9 grams; 1 cup of nonfat Greek yogurt provides 16 grams
  • 1 c of low-fat cottage cheese provides 28 grams

For most animal proteins, one ounce of protein provides approximately seven grams of protein.

Starting your day with a protein-rich breakfast will help get you off to a good start regarding your daily protein intake. I often find that when runners skimp on protein at breakfast, they have unstable energy throughout the day and find it harder to meet their daily protein needs. While the optimal amount of protein that should be consumed at breakfast varies from one runner to the next, aiming for at least 20 grams of protein is ideal.

Tuna Nicoise Snack Plate with Yogurt Herb Sauce

A well-balanced meal combines protein, carbohydrates, and fats. Photo: RWS Health Content + Strategy

Balanced Recipes for Trail Runners and Ultrarunners

Here are a few examples of meals that provide a balanced serving of protein and can help fuel up runners:

Rainbow Tempeh Bowls (Vegan, Gluten-free, Dairy-free)

These bowls balance carbohydrates, protein, and colorful vegetables to help your body refuel and recover after a hard training session.


  • 3/4 c brown rice (dry, uncooked)
  • 3 c broccoli (chopped into florets)
  • 1/2 teaspoon (tsp) avocado oil
  • 9 oz tempeh (cubed)
  • 2 tsp sesame oil (divided)
  • 1/4 c tamari (divided)
  • 2 tablespoons (tbsp) lime juice (divided)
  • 1 tbsp maple syrup
  • 1/4 c plain unsweetened peanut butter
  • 3 carrots (peeled, shredded)
  • 1 red bell pepper (sliced)
  • 1 tsp sesame seeds (optional, for garnish)


  1. Cook the brown rice according to the directions on the package.
  2. Preheat the oven to 400 degrees Fahrenheit (204 degrees Celcius) and line a baking sheet with parchment paper. Add the broccoli and avocado oil and toss to combine. Bake for 15 to 20 minutes. Remove and set aside.
  3. Add the tempeh, half the sesame oil, half the tamari, and half the lime juice in a bowl. Let it sit for five minutes. Heat a non-stick pan over medium heat and add the tempeh. Cook for about eight to 10 minutes, flipping halfway through. Remove and set aside.
  4. In a blender or food processor, add the remaining sesame oil, tamari, lime juice, maple syrup, and peanut butter and blend until smooth and creamy.
  5. Divide the rice, broccoli, tempeh, carrots, and bell pepper evenly between bowls. Drizzle the peanut sauce on top and sprinkle with sesame seeds if using. Enjoy!

Egg and Avocado Quesadilla (Vegetarian, Gluten-free)


  • 1 tsp extra virgin olive oil
  • 3 eggs (whisked)
  • Sea salt and black pepper (to taste)
  • 2 brown rice tortillas
  • 2 oz mozzarella cheese (grated, divided)
  • 1 avocado (medium, sliced)


  1. Heat the oil in a pan over medium heat. Cook the eggs until scrambled and at desired doneness. Season with salt and pepper.
  2. Transfer the egg to a plate. Add one tortilla to the same pan. Top it with half of the cheese. Add the eggs and avocado, then sprinkle the remaining cheese. Close the quesadilla with another tortilla.
  3. Cover the pan with a lid and cook for about four minutes, flipping halfway through.
  4. Cut the quesadilla in half and enjoy!

Lemon Garlic Salmon, Broccoli, and Sweet Potatoes (Gluten-free, Dairy-free)


  • 2 sweet potatoes (small, cut into cubes)
  • 2 c broccoli (cut into florets)
  • 1 1/2 tbsp extra virgin olive oil (divided)
  • 1/4 tsp sea salt
  • 1 tbsp lemon juice
  • 1 garlic clove (minced)
  • 1 tbsp parsley (finely chopped)
  • 12 oz salmon fillet


  1. Preheat the oven to 375 degrees Fahrenheit (190 degrees Celcius) and line a baking sheet with parchment paper.
  2. Add the sweet potato and broccoli to the pan, drizzle with 2/3 of the oil, and season with half of the salt. Stir to evenly coat the vegetables and bake for 10 minutes.
  3. Meanwhile, in a small bowl, combine the remaining oil, lemon juice, garlic, and parsley.
  4. Remove the pan from the oven. Stir the vegetables and make room for the salmon in the center of the pan.
  5. Place the salmon on the pan and season with the remaining salt. Spoon the lemon garlic sauce over the fillets. Continue to bake for 15 minutes or until the salmon is cooked through and the vegetables are tender. Divide between plates and enjoy!

Concluding Thoughts on Protein for Trail Runners and Ultrarunners

Becoming friends with protein is one of the best things you can do nutritionally as a runner to stay strong, support recovery and balanced blood sugar, and replenish glycogen for optimal performance. Furthermore, eating a variety of proteins and timing your protein intake properly around exercise can help you feel and perform your best in training and racing.

Call for Comments

  • Do you regularly supplement your diet with protein?
  • What are your go-to protein sources if you’re a vegan or vegetarian?


  1. Ferrando, A. A., Wolfe, R. R., Hirsch, K. R., Church, D. D., Kviatkovsky, S. A., Roberts, M. D., Stout, J. R., Gonzalez, D. E., Sowinski, R., Kreider, R. B., Kerksick, C. M., Burd, N. A., Pasiakos, S. M., Ormsbee, M. J., Arent, S. M., Arciero, P. J., Campbell, B., VanDusseldorp, T. A., Ralf Jäger, & Willoughby, D. S. (2023). International society of sports nutrition position stand: essential amino acid supplementation on skeletal muscle and performance. Journal of the International Society of Sports Nutrition20(1). https://doi.org/10.1080/15502783.2023.2263409
  2. Coqueiro, A. Y., Rogero, M. M., & Tirapegui, J. (2019). Glutamine as an Anti-Fatigue Amino Acid in Sports Nutrition. Nutrients11(4), 863. https://doi.org/10.3390/nu11040863
  3. Cintineo, H. P., Arent, M. A., Antonio, J., & Arent, S. M. (2018). Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training. Frontiers in Nutrition5(83). https://doi.org/10.3389/fnut.2018.00083
  4. Pasiakos, S. M., Lieberman, H. R., & McLellan, T. M. (2014). Effects of Protein Supplements on Muscle Damage, Soreness and Recovery of Muscle Function and Physical Performance: A Systematic Review. Sports Medicine44(5), 655–670. https://doi.org/10.1007/s40279-013-0137-7
  5. Kato, H., Suzuki, K., Bannai, M., & Moore, D. R. (2016). Protein Requirements Are Elevated in Endurance Athletes after Exercise as Determined by the Indicator Amino Acid Oxidation Method. PLOS ONE11(6), e0157406. https://doi.org/10.1371/journal.pone.0157406
  6. Jäger, R. (2017). International Society of Sports Nutrition Position Stand: Protein and Exercise. Journal of the International Society of Sports Nutrition14(1). https://doi.org/10.1186/s12970-017-0177-8
  7. Sims, S. T., Kerksick, C. M., Smith-Ryan, A. E., Janse, K., Hirsch, K. R., Arent, S. M., Hewlings, S., Kleiner, S. M., Bustillo, E., Tartar, J. L., Starratt, V. G., Kreider, R. B., Greenwalt, C., Rentería, L. I., Ormsbee, M. J., VanDusseldorp, T. A., Campbell, B., Kalman, D. S., & Antonio, J. (2023). International society of sports nutrition position stand: nutritional concerns of the female athlete. Journal of the International Society of Sports Nutrition20(1). https://doi.org/10.1080/15502783.2023.2204066
  8. Tiller, N. B., Roberts, J. D., Beasley, L., Chapman, S., Pinto, J. M., Smith, L., Wiffin, M., Russell, M., Sparks, S. A., Duckworth, L., Sutton, L., Antonio, J., Willoughby, D. S., Tarpey, M. D., Smith-Ryan, A. E., Ormsbee, M. J., Astorino, T. A., Kreider, R. B., McGinnis, G. R., . . . Bannock, L. (2019). International Society of Sports Nutrition Position Stand: Nutritional considerations for single-stage ultra-marathon training and racing. Journal of the International Society of Sports Nutrition16. https://doi.org/10.1186/s12970-019-0312-9
  9. Devries, M. C., Sithamparapillai, A., Brimble, K. S., Banfield, L., Morton, R. W., & Phillips, S. M. (2018). Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis. The Journal of Nutrition148(11), 1760–1775. https://doi.org/10.1093/jn/nxy197


The content provided here is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read here.

The information and recommendations presented here are based on general nutrition principles and may not be suitable for everyone. Individual dietary needs and health concerns vary; what works for one person may not be appropriate for another.

I make every effort to provide accurate and up-to-date information, but the field of nutrition is constantly evolving, and new research may impact dietary recommendations. Therefore, I cannot guarantee the information’s accuracy or completeness.

If you have specific dietary or health concerns, please consult a qualified nutritionist or another healthcare professional for personalized guidance.

Tagged: ,
Guest Writer
Guest Writer is a contributor to iRunFar.com.