The No-Bull Guide to Protein

Yes—we all know increasing strength in a specific muscle group requires specific exercises. Want more finger strength? Hangboard. Looking to build core strength and body tension? Maybe hit the TRX system. Is lock-off strength your goal? Try Frenchies. Exercise specificity is the stimulus for building muscle, as your body adapts to the new workload by building muscle and becoming stronger.

But the equation isn’t as simple as that. If you work hard in the gym without giving your body what it needs to repair and grow, you may do more damage than good. Every climber who trains, or simply pushes herself on the wall, needs to fuel appropriately, supplying the body with protein and amino acids, the building blocks necessary for recovery and strength gains.

So, let’s talk about optimizing protein intake. We’ve all seen the equations for grams of protein per kilogram of body weight, and while getting enough daily protein is a step in the right direction, for climbers, optimizing protein is more nuanced than simply hitting a number. Protein quality, quantity and timing all play roles.

Protein Quality

Protein is comprised of a string of amino acids. Of those, nine are essential, meaning they cannot be produced by the body and must come from diet. The remaining amino acids are non-essential, meaning our bodies can synthesize them from other amino acids—it’s not “essential” to derive them from the food we eat. Because we must obtain essential amino acids from food, essential-amino-acid content determines protein quality, with high-quality proteins rich in essential amino acids and low-quality proteins having fewer (Table 1). Dairy products, eggs, meat and fish rank highest in essential amino-acid content, but protein from plant sources such as quinoa, lentils, peas, and soy are great vegetarian/vegan options.

The FDA uses a digestibility-corrected amino-acid score (PDCAAS) to evaluate protein quality. The PDCAAS accounts for both the essential amino-acid content and digestibility of a protein, with a score of one as the highest possible grade. That score is given to proteins that, once digested, provide 100 percent of the required essential amino acids (Table 1).

While you should look for proteins that are easily digestible and high in essential amino acids, you should also choose proteins with a high Branched Chain Amino Acid (BCAA) content. BCAAs comprise three of the nine essential amino acids. Unlike other essential amino acids, which are broken down in the liver, BCAAs skip the liver and go straight to the muscles, where they play a critical role in preventing muscle breakdown and repairing muscles damaged from exercise. Whey protein and dairy products like milk and yogurt are the best options, but vegan and vegetarian athletes should look to quinoa, lentils and soy for high levels of BCAAs.

Of the three BCAAs, leucine is the most potent stimulator of muscle protein synthesis, the process where protein is produced to repair muscles, with isoleucine and valine playing supporting roles. Increased leucine intake accelerates protein-synthesis rates, and can compensate for less-than-ideal protein levels in your diet.

How much leucine do you need? To maximize muscle repair and growth, aim for two to 2.5 grams of leucine at every snack or meal; conveniently, this is the amount of leucine in 20 to 25 grams of whey protein. One cup of Greek yogurt or cottage cheese will get you in the range, while it will take  about two cups of beans or tofu and four to five cups of oatmeal or quinoa to hit the targeted two to 2.5 grams of leucine (Table 2). Active climbers should select proteins, like whey, soy and pea protein, that are rich in both BCAAs (particularly leucine) and essential amino acids to kick-start muscle protein synthesis, while also providing the building blocks necessary to repair and build new muscle for recovery and adaptation to training.

Climbers who train need 1.6 grams to two grams of protein (twice the RDA recommendation) per kilogram of body weight per day. Photo Dave Burleson/Courtesy Gnarly Nutrition

Vegetarian and Vegan

With an increasing number of athletes now vegetarians or vegans, it’s important to discuss plant proteins and where they fall on the protein-quality scale. Plant proteins have long been incorrectly classified as “incomplete,” meaning that they do not contain all nine essential amino acids. While many plant proteins do in fact contain all nine, others are lower in one or two essential amino acids and relatively lower in leucine. For example, most plant-based options, such as soy, pea and hemp proteins, have a leucine content of six to eight percent, while animal-based sources are in the range of eight to nine percent, and dairy is 10 percent (Table 1). Additionally, plant-based proteins generally have lower digestibility (45 to 80 percent) relative to animal proteins (90 percent or more), an exception being purified plant sources such as soy protein isolate and pea protein concentrate, which are as easy to digest as animal-based sources. For these reasons, plant-based proteins typically rank lower on the PDCAAs scale (Table than animal-derived proteins, and do not stimulate muscle rebuilding and growth as well. Does this mean that athletes cannot thrive on plant-based diets? No, as we’ll see, various diet strategies can significantly improve the muscle-building properties of plant proteins.

Be aware that protein quality is not an issue of animal versus plant sourcing—there are high-quality plant-based proteins and low-quality animal-based proteins.

Consuming a branched-chain-amino-acid supplement before or during exercise can inhibit muscle breakdown. Photo Ben Neilson/Courtesy Gnarly Nutrition

Daily Protein: How much?

The Recommended Daily Allowance (RDA) for protein in adults is .8 grams per kilogram of body weight per day. These RDA values are not only outdated, but they fail to account for the amount of protein required by active climbers.

Athletes should aim for 1.6 grams to two grams of protein (twice the RDA recommendation) per kilogram of body weight per day, but don’t overdo it. Research suggests that getting more protein than that may not have added benefits.

There are also limits to the amount of protein you can benefit from in a single sitting. The positive effects of protein plateau at 20 to 25 grams per sitting, with a caveat for plant-sourced proteins, where 30 grams or more per meal is still beneficial. This strategy will get plant-based climbers closer to an intake of two to 2.5 grams of leucine/snack or meal (Table 2), the amount required to maximize muscle repair and growth. Vegetarian meals that incorporate multiple leucine rich foods like quinoa, lentils and tofu are recommended with high-quality plant-based protein supplements, like pea or soy protein isolate, great options for snacking.

Another option is to add a stand-alone BCAA supplement to your plant protein. Although limited, research suggests that adding BCAA supplements or leucine to plant proteins increases amino-acid transport to muscle, and results in a muscle-building response similar to that created by whey.


Consistency is key. Consuming 20 to 25 grams of high-quality protein throughout the day is more effective than having a single protein-heavy meal. In short, don’t eat all of your protein at dinner, and instead spread it evenly throughout the day. These recommendations hold regardless of your weight, and for most of us this plan would look like three to four meals throughout a nine- to 12-hour eating window. If you are in a heavy training phase or simply need more calories, add one to two more protein-rich snacks and potentially another serving of protein before bed. See the example menus for what this eating strategy might look like for an omnivore, vegetarian and vegan.

A veggie burger is a good option for vegetarians, delivering protein and carbohydrates in one swoop.

Pre- and Post-Exercise

Life can get busy, and following a protein schedule can be difficult. For climbers training regularly, prioritizing your nutrition before, during and after training can go a long way toward replenishing fuel stores, repairing damaged muscle, and restoring fluid and electrolyte balances. Consuming high-quality protein or a branched-chain-amino-acid supplement before or during exercise can inhibit muscle breakdown. Getting a high-quality protein rich in essential amino acids immediately after exercise stimulates muscle repair and growth. Combine protein with carbohydrates after training, and you’ll also replenish your depleted fuel stores.

Ideally, climbers should have a protein-rich meal within two hours before the start of a training session, and/or have stand-alone BCAAs 20 to 30 minutes before training.

To kick-start muscle protein synthesis and replenish fuel stores after hard climbing or training, combine protein with 60 to 75 grams of easily digestible carbohydrates. This might look like a cup of Greek yogurt with some granola and fruit, a black bean and rice burrito with tofu or a whey protein smoothie made with your favorite milk and some fruit.

This article was brought to you by USA Climbing. It appeared in GC #5.

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