Written by Ben Carlisle
Last updated on: Sep 18, 2022
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The suitability of pea protein to support bodybuilding is often asked by those searching for a protein powder as they switch from animal proteins to plant based alternatives. The research on pea protein powder shows promising results for its ability to promote muscle growth when combined with resistance training.
For a muscle to grow, an adequate quantity of protein is necessary, combined with resistance training to break down muscle fiber and then rebuild it bigger and stronger.
Pea protein has proven suitable as a supplement to support the growth of muscle tissue, strength, and performance (1). When engaged in weight training with the intent of increasing muscle size, muscle fibers undergo microscopic damage that, when repaired, leaves the muscles bigger and stronger.
As this is the aim of bodybuilding, pea protein use as a supplement is both advantageous and recommended.
Muscle growth occurs via two paths. Either hypertrophy of the existing muscle fibers occur due to the addition of myofibrils to increase the muscle mass or, additional sarcomeres are created at the ends of the existing muscle fibers which increase their length (2).
The stress caused by exercise has a profound effect on muscle development. But, the muscle can only grow when muscle protein synthesis exceeds muscle protein breakdown. In other words, an athlete must maintain a positive protein balance to achieve increases in muscle size and strength.
While resistance training will improve muscle protein balance, in the absence of adequate food intake (specifically protein but also fat and carbohydrate), the balance remains negative (3).
Muscle protein metabolism occurs within a 24–48-hour period. During this time, the quality and quality of protein ingested at meal times will have a positive effect on the growth of muscle tissue.
The quality of the protein refers to the availability of amino acids and specifically those amino acids contributing to muscle repair and growth.
It is for this reason, the timing of one’s intake of amino acids supportive of muscle synthesis is so important. The increased availability of amino acids will stimulate and maximize muscle protein synthesis in proportion to their quantity. The lack of dietary amino acids will reduce the anabolic effects of exercise.
This means when training to grow muscle, as is the case with bodybuilding, you will need to ensure you are taking adequate amounts of all nine essential amino acids.
We will look at pea protein's overall essential amino acid profile. Then zoom in on the BCAAs which play an important role in muscle protein synthesis.
Pea protein contains all 9 essential amino acids. Aside from the amnio acid methionine, it has a similar essential amino acid profile as whey.
Furthermore, it has excellent levels of branched-chain amino acids (BCAAs), leucine, isoleucine, and valine. In a 100-gram serving of pea protein powder, you will obtain 17.9 grams of BCAAs (4).
Research has recommended a protein intake of between 1.0 to 1.6 grams of protein per kg of body-weight to maintain physical strength and promote muscle mass over time. The recommended protein intake is dependant on physical activity levels. Three recommendations were given 1.0g for minimal, 1.3g for moderate, and 1.6g for intense (5).
You, therefore, need to eat a high-quality protein within a short time after resistance exercise to maximize the potential for muscle gains (6). But it is not only the presence of protein that is important for muscle tissue growth. The quality of the protein plays an important role together with the quantity.
A minimum supplementation of 20-25 grams of protein is required in young adult males and this amount increases with the age of the individual as well as the quality of the protein. The best pea protein powders meet these protein requirements.
Due to pea protein having good levels of quality protein, it is a convenient supplement to support post-workout nutrition for anyone following a bodybuilding regime.
Despite the protein levels of pea being slightly below whey, especially whey isolate powders, it has more than adequate levels for developing muscle mass.
The ability of a protein powder to support muscle building is obviously a great concern to any bodybuilder. Plant based proteins often fall short when compared to whey protein supplements. For muscle building pea comes out on top in direct comparisons with plant based proteins such as "pea protein vs soy protein" and "pea vs rice protein". This is supported by research which has lead to pea protein powders becoming the most popular plant based supplement for building muscle mass.
This research validates the use of pea protein as a substitute for whey protein when training for strength improvement, performance enhancement, and muscle building when used in combination with resistance training.
The results of multiple studies find there is no difference in the muscle-building effects of supplementing with pea or whey protein powders. Athletes who participated in an eight-week study experienced comparable gains in strength and size in both the whey and the pea protein supplement (7). Another twelve-week study found identical results in participants who were supplemented with whey and pea protein (8).
From this, it is clear, the benefits of pea protein powders are on a par with whey protein powder with the additional benefits of it being plant-based, gluten-free and hypoallergenic.
While the exact reason behind pea protein’s positive muscle protein synthesis result is still under discussion, it is thought pea protein’s particularly rich essential BCAAs (valine, leucine, and isoleucine) profile is in part the reason (9, 10).
The amino acid most closely linked to muscle growth is leucine. It stimulates the muscle protein synthesis required to replace muscle protein damaged during strength training.
It was found muscle synthesis was as much as 20% higher after receiving leucine, protein, and carbohydrate compared to receiving protein and carbohydrates without leucine. It was further established, consuming 8 to 11.5 grams of essential amino acids containing 2-3 grams of leucine was the perfect quantity to maximize protein synthesis (11, 12).
However, based on the BCAA amino acid level philosophy, whey protein powders would give superior results to pea protein. With whey protein isolate supplements, in particular, being superior. Whey isolates can contain 10.3 grams of leucine per gram of protein and 21.8 grams of BCAA per gram of protein (13).
Comparing the figures above, we can see pea protein is most suitable for bodybuilding.
For the best results, you should include methionine-rich foods elsewhere in your diet or use a pea protein blend with good levels of all the essential amino acids. This is the reason for including rice protein, as it has a higher level of methionine compared to pea protein.
By supplementing with all the essential amino acids, it has been found muscle protein synthesis is increased when compared to only supplementing with BCAAs or leucine alone (14).
Only supplementing with pea protein will not improve strength and muscle size on its own. One must combine it with a resistance training program to stress the muscles enough to stimulate muscle protein synthesis.
It is well documented resistance training promotes muscle and strength gain (15). However, the findings of one study indicate the load on a muscle does not have to be extreme to experience the benefits of hypertrophy.
Untrained participants experienced the most benefit, while those who had previous training experience benefited from an increased number of training days.
So long as the loads were moderate to high, muscle gains, strength, and performance improved in the presence of protein supplementation (16).
Current research into the differences between training regimes indicates maximum gains in muscle hypertrophy are achieved by training in a way which produces significant metabolic stress while maintaining a moderate degree of muscle tension.
This is the general philosophy behind bodybuilding training, which focuses on the size and visual appeal of the muscles. Powerlifters focus on maximum strength, so their training programs focus more on heavier weights, fewer repetitions, and longer rest periods between sets.
To achieve bodybuilding improvements, individuals should follow a program which includes 6-12 reps per set with 60-90 second rest intervals between sets. The exercises must achieve maximum stimulation of all the muscle fibers by adjusting the angles and planes as each exercise is performed.
Split training employing multiple sets will increase the anabolic effect, as will the use of concentric muscle failure. To ensure the muscles are sufficiently stimulated, alternating micro-cycles of differing speeds can be incorporated into the program while making sure one does not overtrain.
The use of periodization where higher levels of effort are interspersed with less taxing yet higher volume sessions will help to ensure overtraining does not occur while still benefitting from high-stress anabolic activity (17).
Pea protein powder is a suitable bodybuilding supplement as evidenced by the results of multiple scientific studies as well as the presence of champion vegan bodybuilders at professional levels of the sport.
For muscle gain it is the best of the plant proteins. However, it can be improved through the addition of a protein source high in methionine to be a complete protein source. When used in conjunction with resistance training, pea protein achieves comparable results to whey protein powder. This is despite whey being a complete protein with a slightly better amino acid profile. Whether, this equates to better bodybuilding outcomes is yet to be proven.