The only way to build more muscle is to eat proper protein—that’s Sports Nutrition 101. At the most basic level, you need a tub with a single, straight protein source—be it whey, casein, soy, or a plant-blend. But, there are also ingredients commonly added to powders like BCAAs and omega-3s.
So, what's most beneficial to have in your post-workout protein formula? These ingredients.
The barometer for which protein is best revolves around its amino acid concentration. Research shows that proteins with all nine essential amino acids—particularly the three branched chain amino acids (BCAAs) leucine, isoleucine, and valine—maximize muscle protein synthesis (the process of repairing damaged muscle to build back bigger and stronger) best, explains Nancy Rodriguez, Ph.D, RD, director of the University of Connecticut's Sports Nutrition program.
All three of our experts agree, dietary preferences and restrictions aside, whey takes gold. “Whey has a high concentration of the amino acid leucine, is quickly digested, and is a complete source of protein, making it ideal,” says Jacob Wilson, Ph.D, CSCS*D, CEO of the research and performance facility, Applied Science and Performance Institute.
The downside? Some people aren't able to digest whey, as it is a type of milk protein, leaving them to turn to plant-based proteins.
Also a milk protein, casein takes second place in the contest for ideal essential amino acid profile. But whereas whey’s strength comes from its fast-release properties, casein is a slow-release protein, so it provides sustained amino acids in the bloodstream over time to rebuild muscles that were micro-traumatized during exercise, says Lonnie Lowery, Ph.D, RD, professor of exercise physiology and nutrition at the University of Mount Union in Ohio and co-host of the Iron Radio podcast. Since it doesn’t deliver the amino acids to your muscle straight away, it’s best used as a blend with whey. Even better: a blend of casein, whey, and soy protein, which a 2014 study in the Journal of Applied Physiology found enhances muscle recovery and growth more than just whey alone.
“Whey protein rapidly increases blood amino acid pools, which may be optimal for muscle growth,” Wilson says. “However, we know that casein proteins sustain a rise in blood amino acids longer than whey.” Soy is right in between with a medium rate of absorption, so the blend of all three prolongs the delivery of nutrients after a workout.
3. Soy protein
Soy protein is that ideal fast release just like whey, but it's a plant-based protein so it's vegetarian- and lactose intolerant-friendly. “To my knowledge, soy protein is the only plant-based protein that provides all of the essential amino acids,” Rodriguez says. In fact, Canadian researchers found that soy on its own is comparable to whey and superior to slow-release casein when it comes to optimizing muscle protein synthesis post-strength training. And while you've probably heard the rumor that soy can make guys grow boobs (not true, by the way), the bigger problem is that soy is often genetically modified, so opt for organic powders.
5. Plant-based blends
Whether plant-based proteins can hold their own against animal sources has become as heated a debate as our upcoming election. There are studies that show plant-based proteins deliver a lower muscle protein synthesis response than animal-based proteins, but others show little difference. Most experts are in agreement that because most plant proteins lack one or more key amino acids and are thus “incomplete,” downing a single source means you’re not optimizing muscle protein synthesis.
But there is strength in numbers. “I would not rely solely on plant proteins unless I could combine a grain and a legume protein—or spike the plant protein with the missing amino acid(s)—to make it complete,” says Lowery.
And in fact, a study (done in adult rats) in Nutrition & Metabolism found that if the amino acid leucine is added to plant-based protein, the rates of muscle protein synthesis are not significantly different from animal-based proteins. (However, this is only true for higher doses—30% of daily calories—compared to lower doses at 10% of daily calories.)
“Blended plant-based proteins are much more beneficial than single source because drawing from different types will make a more complete protein source, and therefore maximize muscle protein synthesis better,” Wilson agrees.
Look for a formula that has at least one source from the methione-rich camp (hemp, chia, soy), and the lysine and leucine-rich camp (wheat, quinoa, oat, brown rice).
6. Brown rice protein
One study in particular, published in Nutrition Journal, found that guys who consumed 48 grams of rice protein after resistance training saw the exact same gains after eight weeks as those who downed the same amount of whey protein isolate. One study isn’t enough to prove comparability definitively, and research generally shows plant-based proteins are only formidable competitors in high quantities. But if you want to use straight brown rice protein, your safest bet is to also consume foods with the two missing essential amino acids: lysine and leucine (so nuts, seeds, eggs, beans, lentils, meats, shellfish, and cheese).
7. Pea protein
Pea protein, which comes from the yellow split pea, is one of the most popular (and surprising) vegetarian protein sources. It's hypoallergenic and typically has few additives or artificial ingredients in the powder. Plus, it's high in the muscle-building amino acids arginine, lysine, and phenylalanine. However, it's still considered an incomplete protein, so you should either get it through a protein blend or pair it with contrasting foods, like wheat, quinoa, oat, and other grains.
8. Hemp protein
Hemp is rich in essential fatty acids, making it a superfood for building muscle. Plus it's vegan and hypoallergenic, so most people digest the little seed very well. However, like most other plant-based proteins, hemp is incomplete, lacking methione in particular. Make it complete by downing a plant-based blend with hemp in it, or pair it with a protein source rich in the missing essntial amino acids lysine and leucine, like nuts, seeds, eggs, beans, or lentils (not to mention meats, shellfish, and cheese for non-vegans).
Next to protein itself, creatine is the runner up for muscle-building supplements. Creatine helps produce extra energy that your muscle tissue then uses to work harder, for longer. While it doesn't help every body, research shows that if your system is one that reacts well to the formula, creatine can significantly enhance lean body mass, increase strength, and increase muscle size. “Creatine is going to speed recovery, replenish lost creatine stores, hydrate muscle cells, and there is even research that shows it is beneficial for neurological health,” Wilson adds. One thing to watch: “Added peptides like creatine can misleadingly jack up the total protein dose on the label,” Lowery, agrees. points out. So if you buy a formula with creatine, opt for a higher-than-normal protein count.
10. Branched-chain amino acids (BCAAs)
Your system needs all nine essential amino acids for optimal muscle protein synthesis, but three in particular—leucine, isoleucine, and valine—are extra-important because their chemical makeup has a unique branched structure that gives them muscle-building abilities above the other six. Leucine in particular is crucial as it acts as a metabolic trigger to activate muscle protein synthesis, Rodriguez explains. In fact, a study in the Journal of the International Society of Sports Nutrition found that 3 to 4 grams of leucine in particular is necessary for maximum protein synthesis.
Complete proteins, like whey, casein, and soy, probably don’t need additional BCAAs, Lowery points out. But opting for a formula with leucine or BCAAs added to a plant protein can help make up for their inherent lack, he adds. Wilson suggests looking for a formula with 3g of leucine and 5 to 10g of total BCAAs for maximal recovery.
11. Omega-3 and 6 Fatty Acids
By now, most of us know fish oil is pretty damn good for our health. But in one study in the Journal of Sports Science & Medicine, researchers found that omega-3 supplements even help minimize post-exercise soreness. Why? Evidence suggests that omega-3 and omega-6 fatty acids may help reduce inflammation, Rodriguez points out.
“HMB (short for short for β-Hydroxy β-Methylbutyrate) is the metabolite of leucine, meaning when leucine is broken down, one of its products is HMB,” Wilson explains. “HMB has been shown to increase recovery, decrease soreness, improve lean mass, decrease fat mass, and improve blood markers of poor recovery.” In other words, while leucine is beneficial to increase strength, recovery, and muscle size, HMB helps prevent muscle loss in times of excessive training or dieting, so it can be a beneficial addition to a post-workout protein formula.