How to Get the Best Amino Acids for Muscle Growth

Discover the important differences between BCAAs and EAAs for athletic performance, including the best amino acids for muscle growth, workout recovery, plus improved sleep, mood, energy, and fat metabolism.

Muscle protein turnover is a constant state of activity: repairing, replacing, and rebuilding every day. This is true for everyone, though for those who work out or do strenuous labor regularly, the rate is even faster. It’s also true that as we age, this process slows down, meaning the more we do and the older we get, the more support we need to maintain and grow our muscles. Those who hit the gym frequently have probably heard about amino acid supplements, but which are the best amino acids for muscle growth? Branched-chain aminos? The ones in creatine or whey protein? This article has the rundown on the amino acids responsible for muscle synthesis, and advice on how to get all the relevant amino acids for new muscle growth.

Branched-Chain vs. Essential Amino Acids

Branched-chain amino acid supplements (or BCAAs) are incredibly popular workout supplements among athletes and bodybuilders for their purported muscle-building abilities, but BCAAs are only a third of the essential amino acids (EAAs) needed to create new muscle. Here are the important differences when it comes to amino acids for working out.

Branched-Chain Amino Acids

BCAAs are taken as supplements to increase muscle gain, improve muscle recovery, and boost athletic performance. However, it’s a little more nuanced than that on the molecular level.

Branched-chain aminos are so-called because of their chemical structures, the branching chains of their chemical bonds. They are valine, leucine, and isoleucine, and they do indeed play vital and irreplaceable roles in muscle building.

BCAAs are metabolized in your muscles, not via the liver, which means they hit your bloodstream fast when you consume a BCAA supplement, and are especially useful for workout energy. Scientific studies show a link between BCAA consumption and improved glycogen energy storage, decreased workout fatigue, and greater muscle mass. So…what could possibly be the drawback?

The Issue with BCAA Supplements

BCAAs cannot work alone. This meta-analysis of the relevant research done over 30 years (between 1985-2017) found that there are no human studies that show BCAAs working independently to improve athletic performance or increase protein synthesis. While they definitely play a role in new muscle growth, they are not the magic bullet that many fitness enthusiasts are led to believe. How can that be so?

Well, the meta-analysis referenced above highlighted two distinct studies that both showed BCAA supplementation can actually decrease muscle protein synthesis when they are overabundant. As mentioned previously, it takes all nine of the essential amino acids to create new muscle, and without a sufficient amount of every EAA, the excessive amount of BCAAs in the body may accelerate the catabolic rate of muscles (catabolism being a destructive metabolism, the very thing most bodybuilders take supplements to guard against).

In two of the studies profiled, muscle tissue was being broken down much faster than it was being repaired due to the fact that the overwhelming amount of BCAAs in the subjects were seeking to complete their job: achieve protein synthesis. To do this they cannibalized muscle tissue to derive the other six essential amino acids that could not be found quickly enough anywhere else. It’s sort of like the way certain parasites kill their hosts, even though it’s an illogical action: molecules and basic organisms aren’t thinking about the bigger picture, they have one purpose and will clear a path of destruction to complete it if necessary.

Long story short, BCAAs cannot create new muscle alone, without all the ingredients necessary for new protein synthesis, they can actually work against your goals.

Other BCAA Concerns

BCAAs only work to improve muscle growth in those who just so happen to have a sufficient amount of the other essential amino acids in their bloodstreams. Too many BCAAs taken as a solo supplement can have some other negative side effects.

  • A too-high dose of BCAAs can interrupt serotonin production: Serotonin is one of your happy hormones, part of the group of chemicals like dopamine and your endorphins that keep you from feelings of depression and anxiety (among others). Serotonin is synthesized from tryptophan, which uses the same carrier as BCAAs to reach the brain. With extra BCAAs clogging the brain bus, tryptophan uptake decreases, and serotonin production declines.
  • Increased amounts of BCAAs lead to B vitamin depletion: The metabolic requirements of utilizing extra BCAAs includes using several B vitamins, which then leads to a B vitamin shortage. B vitamins are needed for a multitude of other bodily functions, and a deficiency in B vitamins can interrupt hormone production, nervous system functioning, and digestion.
  • Excessive BCAA concentrations can lead to blood sugar and insulin issues: Increased levels of BCAAs may be a predictor of type 2 diabetes onset, and are linked to a higher risk of insulin resistance.

The best amino acids for muscle growth.

Essential Amino Acids

The positive promises of branched-chain amino acid supplements can still be had, so long as you get them in proper balance with the rest of the essential aminos. The best supplements for muscle growth will include all of the amino acids you can’t make yourself, which includes those treasured BCAAs.

Essential vs. Nonessential Amino Acids

Amino acids are known as the building blocks of protein in the body, and have everything to do with muscle gain and protein synthesis. They also have a firm hand in our hormone production, our enzyme creation, our cognitive functioning, and our metabolism.

There are 20 main amino acids in the human body, and while 11 of them can be synthesized in-house and are deemed nonessential, 9 of them are essential to consume from outside the body (like plant and animal protein sources: fish, eggs, beans, etc.). Those nine essential aminos are:

  1. Valine (BCAA): Aids in energy production and stimulates muscle regeneration.
  2. Isoleucine (BCAA): Prevents muscle breakdown and is important in energy regulation and immune system activity.
  3. Leucine (BCAA): Vital in blood sugar regulation, growth hormone synthesis, and protein synthesis.
  4. Lysine: One of the amino acids for joint pain due to its role in collagen, elastin, and our connective tissues.
  5. Methionine: Supports liver function, heart health, and the processing and elimination of body fat.
  6. PhenylalanineHelps synthesize dopamine and norepinephrine, providing antidepressant and pain-killing effects.
  7. ThreonineAnother player in connective tissue (like lysine) and fat metabolism (like methionine).
  8. Tryptophan: The precursor for serotonin, important for appetite, mood, and healthy sleep.
  9. HistidinePrecursor to carnosine, which reduces lactic acid buildup and helps relieve muscle soreness.

Each of the essential amino acids plays a role in either muscle building, fat burning, energy creation, or joint health, or all of the above. Don’t stop at BCAAs when supplementing. Get the full deck of essential amino acids to truly improve your workout and increase your muscle growth.

Get the Essentials for Muscle Growth

To reiterate: BCAAs aren’t bad, they just aren’t the full package that amino acid supplements have to offer. They can’t build muscle all on their own, and too many BCAAs without the rest of their EAA cohort can have counterproductive or even destructive effects on your health.

A full roster of essential amino acids can aid muscle repair, improve exercise recovery, help suppress your appetite (due to the EAAs which work in the brain to regulate satiety and hunger hormones), improve cognitive function, aid weight loss, enhance metabolic processes, and lead to better sleep.

With EAAs, your post-workout recovery improves alongside your body weight, blood flow, lean muscle mass, and muscle strength. Add a complete, well-balanced EAA supplement to your sports nutrition regimen to get the very best of everything.

Should I Take Amino Acids Pre-Workout?

The before, during, or after debate on amino acids for working out can leave you utterly confused as to when you should take your amino acid supplement. I’ll cover the details, but the quick and easy answer to the question should I take amino acids pre-workout is yes!

The before, during, or after debate on amino acids for working out can leave you utterly confused as to when you should take your amino acid supplement. I’ll cover the details, but the quick and easy answer to the question should I take amino acids pre-workout is yes! An amino acid pre-workout powder can help support muscle building, reduce the breakdown of muscle, increase blood flow to the muscle during your workout, and help prevent fatigue and boost performance.

Why Amino Acids Make Ideal Pre-Workout Supplements

You’re taking your sports nutrition goals seriously. You load your plate with whole foods and make sure to prioritize quality protein at every meal. Maybe you’re even incorporating protein powder or other dietary supplements into your regimen. You commit to each training session. You should be seeing major muscle growth gains and yet, you seem to be stuck.

The problem may be that you’re ignoring just how essential a role the fittingly named essential amino acids play when it comes to increasing your muscle mass. No matter how much time you put into weight training, if you fail to provide your muscles with the raw materials they need to grow, you won’t see the results you’re craving.

Key Facts About Amino Acids

You may have heard amino acids described as the building blocks of protein. That’s not a bad description, but it doesn’t entirely do justice to the importance of amino acids.

Not only do amino acids provide structural integrity to protein, but they’re also vital to the synthesis and metabolism of proteins, enzymes, hormones, and neurotransmitters. They regulate the activity of numerous metabolic pathways. They contribute to cognitive function. In short, amino acids are involved in just about everything that occurs inside the human body.

There are 20 amino acids present in the human body. Nine of those are called essential amino acids because unlike the others, your body cannot synthesize them de novo—in plain English, they can’t be made from scratch. Instead, it’s essential that you supply your body with these amino acids via the food you eat or supplements you take.

Researchers have categorized six of the other amino acids as conditionally essential. Under most circumstances, your body can produce these amino acids, but when you’re under extreme duress, that ability becomes compromised.

The remaining four amino acids get grouped together as nonessential. In some instances, you’ll see people refer to 11 nonessential amino acids—when they do so, they’re simply lumping in the 7 conditionally essential amino acids listed above. Your body absolutely needs the nonessential amino acids, but it also has the ability to synthesize them, so it’s nonessential that you get them from your diet.

The easy answer to the question should I take amino acids pre-workout is yes! An amino acid pre-workout powder can help support muscle building and boost performance.

When it comes to using amino acid supplements to facilitate muscle growth and muscle recovery, all the key players can be found on that list of the nine essential amino acids. Here are some key facts about what each of these amino acids does inside your body.

Phenylalanine 

The analgesic (pain-killing) and antidepressant properties of this amino acid typically spark the most excitement. It’s also a precursor to norepinephrine and dopamine, two of the feel-good brain chemicals. When it comes to sports nutrition, the primary benefit of phenylalanine is that due to its ability to raise norepinephrine and dopamine levels in your brain, it may lower your rate of perceived exertion during exercise, helping you stay in a positive headspace through even the most grueling endurance exercise workouts. Our bodies also need phenylalanine to produce metabolism-regulating thyroid hormones.

Valine

A true power player when it comes to muscle synthesis, valine is both an essential amino acid and a branched-chain amino acid (BCAA)—more on these later. One of valine’s main functions is preventing muscle breakdown. That means if you take valine prior to or during an exercise session, it can help decrease muscle damage, allowing you to recover faster. Valine also stimulates your central nervous systems and regulates blood sugar levels.

Threonine

This amino acid helps keep your connective tissues and muscles strong and elastic, in part because it’s a precursor for two other amino acids: serine and glycine. The benefits of glycine have received a lot of attention from researchers lately. Studies show it can encourage muscle growth as well as decrease muscle loss, among other desirable effects. Threonine can also shorten the time it takes your body to heal wounds and recover from injuries. Plus, it supports healthy fat metabolism and stops fat from building up in the liver.

Tryptophan

Another amino acid that serves as a precursor for a feel-good brain chemical—in this case, serotonin, which can help quell physical sensations of pain. That means boosting your tryptophan can increase your tolerance for pain during challenging workouts. The human body also needs tryptophan to manufacture vitamin B3, which ensures your blood sugar levels stay balanced, forestalls free radical damage, and stymies the accumulation of cholesterol.

Isoleucine

Like valine, isoleucine is both an essential amino acid and a branched-chain amino acid. It’s a crucial component of hemoglobin, the protein in your red blood cells that transports oxygen. Our bodies also use isoleucine for muscle repair, which means upping your isoleucine levels lets you bounce back faster from taxing workout sessions.

Methionine

The principal task of this amino acid is to assist your body with metabolizing fat. Plus, it provides your body with the sulfur it needs to produce glutathione, its most abundant antioxidant compound, as well as cysteine and taurine, two other amino acids that contain sulfur. Thanks to its lipotropic properties, methionine can safeguard your liver function by preventing the buildup of fats.

Histidine

This amino acid, which has some antioxidant properties itself, is a precursor to histamine and helps your body synthesize carnosine. This can directly impact your physical performance because histamine can flush the potentially damaging free radicals generated during exercise from your system, while caronsine keeps lactic acid from accumulating in your muscles.

Leucine

Along with valine and isoleucine, leucine is both an essential amino acid and a branched-chain amino acid. It’s the most abundant amino acid found in human muscle tissue. In addition to enhancing stamina and endurance as well as promoting muscle recovery, leucine initiates the process of protein synthesis and helps to maintain your body’s nitrogen balance and energy supplies.

Lysine

Research indicates that lysine can simulate the release of growth hormone, meaning it can offer vital support to your muscle-building efforts. Lysine also ensures you body properly absorbs calcium. Plus, it demonstrates significant antiviral properties and encourages the production of antibodies, making it a phenomenal immune system booster.

Understanding Branched-Chain Amino Acids

Scientific analysis shows that 35% of your muscle protein is composed of three essential amino acids: valine, isoleucine, and leucine. These are, as you may have noticed if you’ve been paying close attention, the infamous branched-chain amino acids (BCAAs). These amino acids get their name from their molecular structures, which have distinctive, branch-like shapes.

The popularity of BCAA supplements with athletes skyrocketed based on studies indicating that they can help to reduce physical fatigue, sharpen mental focus, decrease muscle breakdown, preserve muscle glycogen stores, stimulate muscle protein synthesis, prevent muscle soreness, and more.

Leucine, found in high concentrations in whey protein, is arguably the most important BCAA. But as I mentioned earlier, simply increasing your intake of dietary protein or even adding a whey protein supplement is not the most effective way to benefit from leucine or other amino acids. When taken in supplement form, amino acids can be digested and absorbed more quickly, which maximizes their impact.

As I’ve discussed in previous articles, taking BCAA supplements is also not the most effective way to increase muscle concentrations of these beneficial compounds. There’s no question that BCAAs facilitate muscle growth and optimize athletic performance, but when you take them on their own, they have a minimal impact.

That’s because in order for your body to build complete proteins, it requires all the essential amino acids—and in their appropriate concentrations. Taking a supplement that contains only BCAAs throws off your amino acid balance. Taking an essential amino acid (EAA) supplement that contains the appropriate ratios of all the amino acids needed for protein synthesis is a far better way to amplify your muscle-building results.

When Should I Take My Amino Acids?

Now that you have an increased understanding of how amino acids prevent protein breakdown, facilitate healthy weight loss, improve recovery, and increase energy levels, among other benefits pertinent to those engaged in various physical pursuits, let’s discuss the optimal timing for taking an amino acid supplement.

One of the main reasons to take amino acids for fitness is to build muscle. When you exercise, muscle breaks down in order to release amino acids for the energy the muscles need to contract. Some of the released amino acids are used to rebuild the lost muscle protein. But many of the amino acids are oxidized and cannot be used for muscle protein synthesis. That’s where taking amino acids pre-workout comes in. They help replace the amino acids that are oxidized when your muscle protein breaks down as you exercise.

Taking an amino acid pre-workout powder before resistance exercise is especially important to maintaining and building muscle mass. During resistance exercise blood flows to the muscles at an increased rate. When you ingest amino acids pre-workout, there are more essential amino acids available to strengthen and build muscle.

Taking amino acids before a cardiovascular workout, such as a high-intensity interval training (HIIT class), can help reduce fatigue by balancing the uptake of amino acids that are responsible for the production of the neurotransmitters serotonin and dopamine in the brain.

That said, taking amino acids after a workout (within an hour after exercise) gives your body a boost when it comes to replacing damaged muscle fibers with new muscle protein. Essential amino acids are also important for reducing inflammation, thereby accelerating workout recovery.

To maximize all the beneficial effects of amino acids, it’s best to take a high-quality essential amino acid blend both before and after exercise. If you’re carrying out a resistance-training regimen, you may also see benefits from taking amino acids during your training sessions. This approach to amino acid supplementation is optimal for improving muscle strength as well as accelerating recovery.