What Are Amino Acids?

STACK explains what amino acids are, how to get them and why they are so important for athletic performance.

Amino acids. You've probably heard those words before, but do you really know what they mean? Where do they come from? What do they do? Why are they a common ingredient in athlete supplements? If you've got questions, STACK's got answers. Here's everything you need to know about amino acids.

What are Amino Acids?

Amino Acids

According to the National Library of Medicine, amino acids are "organic compounds that combine to form proteins." More specifically, they're organic compounds that contain at least one amino group and one carboxyl group.

Amino acids are mainly known for their role as the building blocks of protein. Although over 50 amino acids are currently known to exist, only about 20 of them are used to make the proteins in the body. How amino acids come together to form a protein helps determine the structure and function of that protein.

There are three groups of amino acids: essential, nonessential and conditional. Essential amino acids are the nine amino acids that cannot be made by the human body. We must get essential amino acids through food. Nonessential amino acids are amino acids that our bodies can produce. Conditional amino acids are amino acids that a healthy human body can produce, but certain conditions might limit one's ability to do so, thus forcing one to turn to diet and/or supplementation to get them.

Since this article is mainly about the nutritional role of amino acids, we're going to focus on the essential amino acids.

What Do Amino Acids Do?

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The functions of amino acids range widely, from synthesizing neurotransmitters to regulating blood pressure to being metabolized for energy. But no job is more important for amino acids than serving as the compounds that form protein.

When we digest the protein found in food, it is broken down into specific amino acids, which are then selectively reassembled into proteins once again. Most of the solid matter in our bodies—bones, muscles, organs and skin—is made up of these proteins. That's why protein—and thus, amino acids—are incredibly important for muscle-building and recovery. Protein also helps regulate energy levels and facilitate cell communication.

RELATED: Why Protein is Important for Athletes

Why are Amino Acids Important for Athletes?

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Amino acids—specifically, essential amino acids—are important for athletes because they allow our bodies to continue producing protein. Our bodies need protein to function, and athletes rely on protein for recovery, muscle growth and optimum immune system function. Coming up short on just one essential amino acid can wreak havoc on your athletic performance and overall health.

If your diet doesn't include all of the essential amino acids, your body starts breaking down muscle tissue as a way to access them. This is obviously a terrible thing for athletes—the body essentially cannibalizing it's own muscle mass for fuel. This alone is a major issue, but a lack of essential amino acids can also result in reduced energy and attentiveness. Losing muscle mass, feeling tired all the time and losing an ability to focus? Yeah, those sound like big problems for athletes.

How Do I Include Essential Amino Acids in My Diet?

Amino Acid Food Sources

Understanding the concept of "complete" protein and "incomplete" protein is key to figuring out whether you're getting a substantial amount of essential amino acids in your diet.

Complete proteins come from protein sources that contain adequate amounts of all nine essential amino acids. Animal proteins such as seafood, poultry, red meat, eggs and dairy are all complete proteins. But vegetarians and vegans can also find complete protein sources. Foods like soybeans, quinoa, hempseed and buckwheat are plant-based sources of complete proteins.

An incomplete protein refers to a protein source that does not contain all nine essential amino acid (or in certain cases, not enough to be effective), but does contain some. Examples of incomplete proteins are most grains, cereals, nuts, lentils and seeds. You can combine two incomplete proteins to make a complete protein. Examples include peanut butter on wheat bread and rice and beans.

RELATED: The Vegetarian Athlete: Combining Foods for Peak Performance

With that in mind, if you're eating a well-balanced diet, you're probably already consuming enough essential amino acids. Even if you are vegetarian or vegan, if you eat enough different incomplete protein sources, your body will be able to combine them into complete proteins after digestion.

Why Do People Take Amino Acid Supplements?

Amino Acid Supplements

When you hear about athletes taking amino acid supplements, odds are they're taking BCAAs, or branched chain amino acids. BCAAs comprise three specific types of amino acids—leucine, isoleucine and valine. Although a balanced diet provides BCAAs, athletes take them in supplements for a couple of reasons.

One is simply because they believe more is better. Even if they're getting plenty of BCAAs in their diet, certain athletes think consuming more of them confers greater benefits. Many athletes who take BCAAs take them during or right before a workout, in part because they believe BCAAs help their body avoid burning protein as an energy source. There's also the idea that taking BCAAs allows for quicker absorption, since the body doesn't have to take time to break down real food into amino acids. Certain studies have found that BCAAs can help fight fatigue and aid recovery for endurance athletes, although the research is conflicting.

RELATED: Should You Be Taking BCAAs?

Examine, an independent site that collates scientific research and disseminates information on supplementation and nutrition, states that "BCAA supplementation, for people with low dietary protein intake, can promote muscle protein synthesis and increase muscle growth over time."

The words "low dietary protein intake" are crucial. If you're already getting sufficient protein in your diet, BCAA supplements are probably not worth your money. You're better off sticking to real foods and using supplements that contain protein—such as whey protein products—than relying on BCAAs. "BCAAs are important to ingest on a daily basis, but many protein sources, such as meat and eggs, already provide BCAAs. Supplementation is unnecessary for people with a sufficiently high protein intake," Examine states.

If you'd like to give them a try, feel free—BCAAs aren't banned by the NCAA or high school athletic associations. But overall, focusing on eating a well-balanced diet with a variety of foods that contain essential amino acids is a better use of your time and money.


Topics: PROTEIN | DIET | FOODS | ENERGY | AMINO ACIDS | SUPPLEMENT | PROTEIN SOURCES | VEGETARIAN | ESSENTIAL AMINO ACIDS | BCAAS