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Athlete shaking a Blonyx shaker cup filled with Egg White Protein Isolate

Why the Source of Your Protein Powder Matters

As an athlete, you know that protein is essential for muscle growth, repair and supporting your overall performance. But did you know that the source of your protein powder can significantly impact its effectiveness?

Not all protein sources are created equal, and choosing the right one can make a significant difference in how you structure and optimize your sports nutrition plan.

In this article, we help you make an informed decision about which protein source is best for you by covering:

  • The protein needs of training athletes
  • How to evaluate different protein sources for supplementation
  • Our recommendation for the best protein powder for athletes


The Protein Needs of Training Athletes

Your protein needs can vary depending on your activity level and training goal, but your body requires about 1.0–1.5g/kg of body weight daily to maintain existing muscle mass. However, training athletes often need up to 2.0g/kg body weight daily—sometimes more.

We like this 2024 study addressing common questions and misconceptions about protein powder supplementation for athletes and non-athletes alike, and the researchers drew some interesting conclusions. Here are three things that stood out to us:

  • Endurance athletes need additional protein: Endurance athletes often need at least twice the recommended daily amount of protein. This is because, during long periods of exercise (more than 2 hours), your body starts using muscle protein for energy, which can result in muscle loss—eating more protein helps prevent this. Additionally, higher protein intake helps your body use energy more efficiently and boosts mitochondria function, leading to greater energy production.
  • Your daily protein consumption is more important than when you get it: You don’t need to consume protein within one hour of strength training to create a muscle-building environment. Your body remains receptive to protein intake for much longer than one hour post-exercise, and your total daily protein intake is most important. Pre-exercise protein ingestion has also shown to be effective, making steady protein consumption throughout the day key.
  • Treating protein powder differently than typical protein-rich foods doesn’t make scientific sense: You don't need protein powder to meet your daily protein needs, but it can be extremely helpful. If you exercise regularly, you need more protein, and while you can get it from food, protein powder makes it easier to meet your high protein demands without eating too much. So, while not necessary, protein powders can be a practical alternative when real food is unavailable or inconvenient—but we’ll always recommend going for real food when you can. 

We also covered this study in one of our weekly research summaries—click the link to get our thoughts on it.


Understanding Protein Sources

Knowing your protein needs is just the first step of protein supplementation. The next step is choosing a protein powder that aligns with your specific needs. All of the different protein powders on the market offer varying flavours and levels of digestibility, efficiency and allergenicity (the ability to induce an abnormal immune response).

These are all crucial things to consider when choosing a protein powder, and it can be difficult to decide what will work best for you

So, we compared common protein sources to help you out—read on.


Flavour and Digestibility

Egg White Protein

Egg white protein is known for its neutral taste and smooth, creamy texture, which allows it to blend seamlessly with just about any ingredient you may want to add to your shake or smoothie. It’s highly digestible, reducing the likelihood of gastrointestinal discomfort, which is a common issue with other protein powders like whey.

Whey Protein

While highly effective, whey protein can cause bloating and digestive issues due to its lactose content. Its taste can be somewhat chalky if not flavoured adequately, which some may not enjoy. Additionally, whey is rapidly digested, making it ideal for post-workout recovery but less suitable for sustained protein release.

Casein Protein

This slow-digesting protein creates a feeling of fullness and is best consumed before bedtime to aid overnight recovery. However, its thick texture and potential to cause bloating make it less ideal for some athletes. Casein’s slow absorption rate provides a steady release of amino acids, making it excellent for prolonged muscle repair.

Plant Protein (Soy and Pea)

Plant-based and suitable for vegan athletes, soy protein has an earthy taste that may not appeal to everyone, and it can cause digestive issues in some individuals due to its fibre content. Soy protein is a complete protein, meaning it contains all essential amino acids, but it has lower digestibility compared to animal proteins.

Pea protein, another popular plant-based option, has a mild taste and smooth texture, making it a versatile addition to various recipes. While not a complete protein on its own, it can be combined with other protein sources, like rice protein, to achieve a complete amino acid profile. Pea protein is generally well-tolerated and less likely to cause digestive issues compared to soy.


Protein Efficiency Ratio (PER) and Biological Value (BV)

Here’s where we get into the data. There are two common tests for the quality and efficiency of a protein source: Protein Efficiency Ratio (PER) and Biological Value (BC). 

Protein Efficiency Ratio is a way to measure how well a protein supports growth. It looks at how much weight an animal gains when fed a specific protein source. The higher the PER, the more effective the protein is at promoting growth. 

Biological Value is a measure of how well your body can absorb and use the protein you eat. It looks at the amount of protein that is retained in your body for growth and maintenance. The higher the BV, the more efficiently your body uses that protein.

Below are both of these values for each protein source we’ve discussed so far, pulled from this study by the International Society of Sports Nutrition.  

Egg White Protein

Egg white protein boasts the highest PER of 3.9 and a very substantial BV of 100, indicating superior quality for supporting muscle growth and efficient protein utilization. Its high digestibility and complete amino acid profile ensure that the body can utilize it effectively.

Whey Protein

Whey protein has a PER of 3.2 and the highest BV of 104, making it a common choice for post-workout recovery. Whey protein’s rapid digestion helps quickly supply muscles with the necessary amino acids.

Casein Protein

Casein protein has a PER of 2.5 and a BV of 77, suitable for prolonged protein release. Its ability to form a gel in the stomach leads to a slow, steady release of amino acids, making it excellent for prolonged muscle repair.

Plant Protein (Soy and Pea)

Soy protein has a PER of 2.2 and a BV of 74. Soy protein’s complete amino acid profile makes it a valuable plant-based option despite its lower digestibility.

Pea protein has a PER of 2.1 and a BV of around 65, indicating good support for muscle growth and utilization, though slightly less efficient than soy and animal-based proteins. It remains a strong option for those looking for a plant-based alternative.



Egg White Protein

Egg white protein is generally well-tolerated and less likely to cause allergic reactions compared to other protein sources. It’s suitable for most people who consume animal products and has a very low potential for gastrointestinal discomfort.

Whey and Casein Protein

Both whey and casein proteins are not suitable for those with dairy allergies or lactose intolerance. If your body struggles with lactose, you will experience stomach issues.

Plant Protein (Soy and Pea)

Soy is a common allergen, and some may have concerns about phytoestrogens affecting hormone levels.

Pea protein, on the other hand, is hypoallergenic and less likely to cause allergic reactions or digestive issues. This makes it a suitable alternative for those who have allergies to soy or dairy.

A Note on Plant Protein

Studies have found that plant-based protein powders contain higher levels of heavy metals such as arsenic, cadmium, mercury and lead. These metals are present due to soil contamination and are more likely to accumulate in plant-based products.


Our Recommendation

We believe that athletes should prioritize real food in their diet and supplement choices. Our Egg White Protein Isolate stands out from other protein powders for its high digestibility, excellent bioavailability and superior protein efficiency. Put simply, your body can use it for muscle growth and repair more easily since it’s quite literally just real food—egg whites.

Egg whites are the highest-purity and most efficient protein source that exists as a real, unprocessed food, making it easier for your body to digest and utilize for muscle growth and repair.

Unlike other highly processed protein powders, Egg White Protein Isolate is very simple to make. This ensures you get a pure and effective protein source without any unwanted additives or contaminants, making it a versatile addition to your sports nutrition plan, no matter what type of athlete you are. 

For a deeper dive into how Egg White Protein Isolate is made and why egg whites are our go-to protein source, check out our article: The Inside Scoop: How We Make Our Egg White Protein Isolate (and Why).


If you learned something new from this article and are curious to know more, head to the Blonyx Blog or our growing list of weekly research summaries where we help you further improve your athletic performance by keeping you up to date on the latest findings from the world of sports nutrition.


— That’s all for now, train hard!


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