Amino Acids and Muscle Recovery After Exercise

Amino acids and muscle recovery go hand in hand. You need all 20 amino acids that make up the proteins in your body for optimal muscle recovery. Without amino acid support, your body eats away at its own muscle tissue for energy. We’ve got the scoop.

If you’re a fitness enthusiast, you probably tend to focus much more on the doing—sprinting, lifting, contracting—than on the process of recovery. However, if you don’t allow your muscles to recover, you can’t perform, compete, or train at your best. For just as our brains process information and create and consolidate memories as we sleep, so, too, do our muscles resynthesize, recalibrate, and grow when we rest. But did you know that you can also accelerate muscle growth during recovery by boosting muscle protein synthesis with amino acid nutrition? If you’re interested in increasing both muscle mass and exercise performance, come with us as we explore the fundamental relationship between amino acids and muscle recovery.

What Happens to Muscle During (and After) Exercise?

Every time you engage in exercise your muscles aren’t used to, some muscle damage occurs. And whether you’re an endurance athlete or into strength training, this unfamiliar stress leads to microscopic tears in the muscles. You’ve probably noticed the discomfort this causes a day or two after a high-intensity workout. Known as delayed onset muscle soreness (DOMS), this post-exercise pain is the result of the tension muscles experience during eccentric (lengthening) exercises.

Believe it or not, these microscopic tears and the muscle protein breakdown they lead to have to happen if muscle strength and mass are to increase. When muscle fibers are damaged, satellite cells rush in to fuse the damaged fibers together, and this creates newer, stronger, and larger muscle fibers.

Think of satellite cells as stem cells for your muscles. Not only are these precursors to skeletal muscle cells made of protein—and therefore amino acids, the building blocks of protein—but they’re also essential for muscle repair after a workout. Moreover, they stimulate the production of more durable muscle, and this leads to better muscle function.

Amino Acids and Muscle Recovery

According to a 1995 study, muscle protein synthesis (the process of building muscle) is elevated by 50% 4 hours after high-intensity resistance training and by 109% 24 hours post workout. So for the next 24 to 48 hours after intensive exercise, your body needs plenty of protein-rich foods and the amino acids they contain to supply your muscles with the nutrients they need to grow in size and strength.

In other words, amino acids and muscle recovery go hand in hand. In fact, you need all 20 amino acids that make up the proteins in your body for optimal muscle recovery. Eleven of these amino acids are produced in the body, but nine are essential amino acids (EAAs), which means they must be consumed in the diet because they’re not produced in the body.

Increasing protein intake after a workout with the use of a balanced EAA supplement or even protein supplements, such as protein shakes or whey protein—which contain all the EAAs—is an effective way to activate muscle protein synthesis and aid in muscle recovery.

Increasing consumption of EAAs also stimulates reutilization of the 11 nonessential amino acids (NEAAs) for protein synthesis, thereby decreasing their oxidation and resultant increase in the byproducts ammonia and urea, which further aids muscle recovery.

What all this means is that providing your muscles with the amino acid nutritional intervention they require helps keep your muscles protected. The reason for this is that protein is used by the body for almost every biological process, and the majority of that protein is locked up in muscle tissue. So if the availability of amino acids to rebuild the protein lost during muscle breakdown is limited, not only does muscle protein synthesis suffer, but your body also has no choice but to use its own muscle to keep the rest of the machine running.

Branched-Chain Amino Acids and Muscle Recovery

Branched-chain amino acid supplementation has become popular among bodybuilders and other workout buffs to help increase athletic performance. On the face of it, this makes sense, as branched-chain amino acids (BCAAs)—leucine, valine, and isoleucine—make up nearly 35% of muscle tissue and are a source of fuel for the muscles.

However, while this may accelerate recovery from muscle soreness, BCAAs are limited in their ability to stimulate muscle protein synthesis. This is because all the EAAs are required for a complete protein to be produced. In fact, a recent study demonstrated that taking BCAAs alone has either no effect or only a minor one on the rate of muscle protein synthesis.

Why is this?

Research has shown that the availability of all the EAAs determines the rate of muscle protein synthesis. So even if you’re consuming a BCAA supplement after your workout, the rate of muscle building is still going to be determined by how many of the other EAAs are present. This is because you can’t make a complete protein out of just three amino acids, so unless you’re also getting enough of the other six EAAs, the effectiveness of BCAAs will be limited.

In addition, an excess of BCAAs has been shown to disrupt levels of neurotransmitters in the brain. In fact, a 2013 study found that BCAA supplementation, when used in isolation, lowers levels of several important neurotransmitters, including catecholamines, which are necessary for enhanced athletic performance. So to get the most out of your exercise routine—and your muscles—you must consume BCAAs as part of a balanced mixture of all the EAAs.

However, even though consuming both protein and amino acid supplements after exercise can provide important benefits, it’s important to realize that they’re merely supplements to your regular diet. If you really want to give your muscles the nutritional support they need, focus on refueling your body after your workouts with foods that are abundant in amino acids.

Consuming between 0.5 and 0.9 grams of protein per pound of body weight should provide you with the right amount of amino acids to help increase your muscle mass and improve your athletic performance.

Foods high in amino acids

BCAA Amino Acids: What You Should Know About These Much-Hyped Muscle Builders 

The acronym “BCAA” stands for branched-chain amino acids. Read on to learn about the science behind the much-hyped beneficial effects of BCAA amino acids, including crucial information on how to maximize the impact of increased BCAA intake.

The acronym “BCAA” stands for branched-chain amino acids, a term used to refer to three essential amino acids:

  • Leucine
  • Isoleucine
  • Valine

The descriptor “branched-chain” refers to the unique molecular structure of the three BCAA amino acids.

Much of the interest in the benefits of BCAA dietary supplements has been driven by athletes who believe these amino acid supplements can help to build muscle mass, accelerate muscle recovery, diminish muscle soreness after intense activity, improve exercise performance, increase energy production, and more. There’s even some evidence that the effects of BCAA supplementation include more balanced blood sugar levels and the facilitation of fat loss.

Read on to learn about the science behind the much-hyped beneficial effects of BCAA amino acids, including crucial information on how to maximize the impact of increased BCAA intake.

What You Should Know About BCAA Amino Acids

Of the 20 amino acids the human body uses as building blocks to make proteins, nine are deemed essential because the body cannot produce them, meaning they must be obtained from the food a person eats or from targeted supplementation. As mentioned above, the three BCAAs, leucine, isoleucine, and valine, are essential amino acids. If you wish to access their remarkable benefits, you must provide your body with an adequate supply from your diet or from supplements.

Many healthy, high-protein foods naturally contain BCAAs, such as:

  • Red meat, poultry, fish and other seafood
  • Eggs, milk, cheese, and other dairy products
  • Nuts and seeds
  • Soybeans and products made from soy such as tofu and tempeh
  • Legumes like beans, peas, and lentils

8 Foods with Naturally High Levels of BCAAs

8 Scientifically Validated Benefits of BCAAs

The popularity of BCAA supplementation is supported at least in part by diligent research into the proposed benefits of these amino acids.

One of the best-known and most agreed-upon benefits of BCAAs is their ability to increase muscle protein synthesis and decrease muscle protein breakdown, thus encouraging increased muscle growth.

However, the benefits of BCAAs are not limited to bodybuilders and those seeking to enhance the effects of their workouts. Read on to learn about the science behind eight effects of BCAA supplementation.

1. Build Muscle Mass

One of the famous uses for BCAAs supplements is as a means to build muscle mass.

Leucine, the most potent of the BCAAs, activates the rapamycin complex (mTOR) signaling pathway, thereby stimulating muscle protein synthesis. According to a study published in the Journal of Nutrition, leucine has an impressive anabolic effect on skeletal muscle, which leads to impressive muscle-building results.

A study published in Frontiers in Physiology found that when people took BCAAs post-workout, they had a 22% increase in muscle protein synthesis compared to those who consumed a placebo drink.

However, even more impressive results ensue when leucine and the other BCAAs are ingested in combination with all the essential amino acids necessary for muscle building. Based on the findings of a study published in the American Journal of Physiology-Cell Physiology, taking BCAAs along with the other essential amino acids can result in at least 18% greater muscle-building activity.

2. Improve Exercise Performance

Yet another benefit of BCAAs many people find appealing is their ability to improve exercise performance.

A study published in the Journal of Exercise Nutrition & Biochemistry found that taking pre-workout BCAA supplements produced significant changes to substances linked to energy metabolism and physical fatigue.

The study authors concluded that, thanks to their demonstrated ability to lower concentrations of serotonin, a neurotransmitter that produces a fatiguing effect, BCAAs can then produce a cascading effect that limits the influence of other substances related to fatigue and energy production. “Therefore, the intake of the BCAA is presumed to help contribute to enhancing exercise performance,” the authors stated.

3. Minimize Mental and Physical Fatigue

As noted above, the physiological basis for BCAAs’ ability to enhance exercise performance has to do with their effect on substances related to fatigue and energy production.

A 2016 study published in the Journal of Sports Science and Medicine showed that when endurance runners took a BCAA supplement, their performance significantly improved.

The researchers who conducted the study attributed this effect to the impact BCAAs have on serotonin, which as discussed in the previous section, is a neurotransmitter that promotes fatigue during exercise. BCAAs inhibit the production of serotonin during exercise, thereby helping to reduce fatigue so endurance athletes can run faster and go longer.

4. Reduce Muscle Damage and Accelerate Muscle Recovery

A study published in the Journal of the International Society of Sports Nutrition also showed that BCAA supplements can reduce muscle damage and accelerate recovery when taken before and after resistance exercise.

“The present study has shown that BCAA administered before and following damaging resistance exercise reduces indices of muscle damage and accelerates recovery in resistance-trained males,” the study authors wrote. “It seems likely that BCAA provided greater bioavailablity of substrate to improve protein synthesis and thereby the extent of secondary muscle damage associated with strenuous resistance exercise.”

A separate study published in The Journal of Sports Medicine and Physical Fitness shed light on the mechanism by which BCAAs are able to reduce the markers of muscle damage. It appears that they can decrease levels of two prominent enzymes that contribute to muscle breakdown—creatine kinase and lactate dehydrogenase.

5. Alleviate Muscle Soreness

BCAA amino acids’ influence on muscle soreness was demonstrated by a study from the International Journal of Sport Nutrition and Exercise Metabolism.

The crossover, double-blind study looked specifically at the effect of BCAAs in delayed-onset muscle soreness (DOMS).

Participants who took BCAAs prior to their workouts experienced significantly lower levels of soreness than those who took a placebo. This translated to improved muscle force on the following day as well.

6. Regulate Blood Sugar Levels

More research needs to be done to confirm this BCAA benefit, but it appears that taking these amino acids can help you maintain balanced, healthy blood sugar levels.

Studies done with rats indicate that isoleucine may have the most pronounced impact on insulin secretion of the three BCAAs, though leucine also seems to play a role in increasing the uptake of sugar by muscle tissue, a process which subsequently lowers blood sugar levels.

At least one study with human participants also indicated a beneficial effect of BCAAs on blood sugar levels.

7. Support Weight-Loss Efforts

The ability of BCAAs to propel lean muscle growth seems to be linked to the encouragement of fat loss.

A 2009 randomized, double-blind study found that BCAA supplementation, paired with a resistance-training program, resulted in a greater decrease in percent body fat and increase in lean muscle mass than either whey protein or a carbohydrate-based sports drink.

Study participants, all of whom had previous strength-training experience, were divided into three groups. The first took 14 grams of BCAAs, the second 28 grams of whey protein, and the third 28 grams of a carbohydrate-based sports drink. All three groups completed the same 8-week training regimen. At the study’s conclusion, participants in the BCAA group gained an average of 4 kilograms of lean mass and lost an average of 2 kilograms of body fat.

8. Improve Liver Function

Last but certainly not least, there’s some evidence indicating that BCAA supplementation can improve liver function.

A 2017 study looked at the effect of BCAAs on the symptoms of patients with advanced liver cirrhosis over the course of 6 months. The results of this nationwide, multi-center, retrospective, observational, cohort study conducted by a preeminent team of Korean researchers showed that the long-term use of BCAAs had pronounced benefits for individuals with liver disease.

At the study’s conclusion, the Model for End-Stage Liver Disease (MELD) test scores of participants who took BCAAs had improved considerably in comparison to those in the placebo group. MELD scores determine the degree of severity of a person’s liver disease based on blood levels of substances like creatinine and bilirubin.

8 Top Health Benefits of BCAA Supplementation

In addition to the health benefits mentioned above, medical professionals have used BCAAs to treat:

  • Lou Gehrig’s disease
  • Brain conditions related to liver disease such as chronic hepatic encephalopathy and latent hepatic encephalopathy
  • A genetic disease called McArdle’s disease
  • A movement disorder called tardive dyskinesia
  • Spinocerebellar degeneration
  • Poor appetite in cancer and kidney failure patients
  • Slow muscle wasting in bedridden individuals

How to Get the Best Results from BCAA Supplementation

Though BCAAs are one of the most popular supplements in the fitness community, they are also some of the most misused. BCAA amino acids can, without a doubt, help build muscle and boost performance, but when taken on their own, the much-coveted results associated with their use will be dampened at best and entirely absent at worst.

That’s because taking a BCAA supplement containing solely the three BCAA amino acids (leucine, isoleucine, and valine) will have minimal effect on protein synthesis. In order for your body to build complete proteins it needs an infusion of all the essential amino acids in their appropriate concentrations. Taking only a BCAA supplement disrupts the balance of the amino acid pool. Rather than reaping the benefits known to be associated with an increased intake of leucine, isoleucine, and valine, you’re likely to see only minimal gains, if any at all.

When paired with a complete amino acid complex, however, the results of BCAA supplementation can be quite dramatic. To learn more about best practices for BCAA supplementation, read this article by Dr. Robert Wolfe.

How to Combine EAA Supplements with Aerobic Exercise for Maximum Benefits

Are there any advantages to consuming EAA supplements or BCAA supplements before aerobic exercise? Here’s what you need to know in order to combine essential amino acid (EAA) supplements with aerobic exercise for maximum benefits.

Jogging. Swimming. Cycling. Dancing. What do all these activities have in common? They’re aerobic, which means the heart is pumping oxygen-rich blood to your working muscles. Your heart is beating faster, blood is flowing from your muscles to your lungs, and you’re producing endorphins, those feel-good hormones that naturally put you in a better mood. The benefits of amino acid supplements for bodybuilders striving to increase their muscle growth are quite well-known, but the ways amino acids can enhance the effect of aerobic exercise receive less attention.

Here’s what you need to know in order to combine essential amino acid (EAA) supplements with aerobic exercise for maximum benefits.

What Are Essential Amino Acids (EAAs)?

There are many different types of amino acids as well as a variety of ways to divide them into categories. In terms of dietary supplements, however, two specific groups of amino acids unequivocally reign supreme: essential amino acids (EAAs) and branched-chain amino acids (BCAAs). You can read this article if you’re interested in a more thorough run-down of the differences between the two, but for now, it’s sufficient to understand that the term branched-chain amino acids refers to a subgroup of three essential amino acids: leucine, isoleucine, and valine.

The reason essential amino acids are referred to as essential is that, unlike the other 11 nonessential amino acids, your body cannot synthesize them de novo. Instead, it requires an external supply of these vital amino acids from the food you eat or other sources, such as supplements. There are nine EAAs total:

  1. Histidine
  2. Isoleucine
  3. Leucine
  4. Lysine
  5. Methionine
  6. Phenylalanine
  7. Threonine
  8. Tryptophan
  9. Valine

Each EAA has its own distinct and important functions within the human body. Some of these amino acids, like the three BCAAs, have particularly exciting effects. Valine, for instance, helps prevent the erosion of muscle mass during exercise. This limits muscle damage and post-workout soreness, helping you to recover more quickly and perform at full function again faster.

What many people do not fully grasp, however, in part because of the misleading claims put forth by unethical manufacturers, is that it is impossible to access the benefits of any single EAA without a supplemental, well-balanced dose of the remaining eight EAAs.

Quick Facts About the 9 Essential Amino Acids

Why EAA Supplements Outperform BCAA Supplements

Much of the research on the benefits of amino acid supplements for improving exercise performance has been focused on the use of BCAAs rather than on essential amino acid supplements. As we explained in the previous section, however, solely increasing your intake of BCAAs will not allow you to obtain the full benefits associated with those amino acids. In order to bring about the positive changes you desire, you must provide your body with an optimally balanced dose of all the EAAs.

To illuminate why that is, let’s look at a specific amino acid: leucine, one of three branched-chain amino acids (BCAAs) and the most abundant essential amino acid in muscle.

Leucine promotes muscle recovery after vigorous workouts, boosts stamina and endurance, and enhances anabolism (the muscle-building component of the muscle protein synthesis process). But, unlike other essential amino acids, leucine (and its BCAA comrades isoleucine and valine) undergoes oxidative degradation during aerobic exercise.

Given that the body can use leucine for energy during aerobic exercise, it may seem reasonable to supply extra leucine to offset the oxidation that transpires during the muscle protein breakdown process. Here’s where things get muddled.

When you introduce more leucine or BCAAs into the bloodstream, a greater percentage is oxidized. That’s because the body is designed to keep a balanced composition of amino acids available in the blood, so mechanisms kick in to reduce the leucine you’ve ingested.

To avoid that dilemma, it’s best to take a supplement containing all nine essential amino acids.

A 2018 study conducted by researchers from the University of Texas looked at the effect of EAAs and aerobic exercise on skeletal muscle protein anabolism. The goal of the Phase 1, double-blind, placebo-controlled, randomized clinical trial was to determine if ongoing EAA supplementation with 15 grams taken daily, supervised aerobic training 3 days weekly, or a combination of the two interventions could increase muscle mass and function by stimulating muscle protein synthesis.

The researchers measured muscle strength, physical function, body weight and composition, and muscle protein synthesis both before and after the 24-week trial. Only participants who took the EAA supplement showed improvements to muscle strength and muscle protein synthesis.

Timing Your EAA Supplement Doses for Maximum Impact

Though the study cited above did not specify the times at which participants took their EAA supplements, scientists have found that due to the oxidation of BCAAs that transpires during aerobic exercise, the time at which you take your supplements can markedly impact the extent of the benefits you experience.

Pre-Workout EAA Supplements: The Bottom Line

The efficiency of the supplement is considerably reduced when taken pre-workout or during aerobic exercise when the metabolic pathways of BCAA oxidation are already revved up. Consequently, the supplemental leucine or BCAAs will not be available to promote muscle protein turnover.

Nonetheless, ingesting leucine or BCAAs before or during exercise will offset to some extent the accelerated oxidation of these amino acids, as long as all the EAAs are provided. Perhaps more importantly, increasing BCAAs and phenylalanine during exercise encourages the synthesis of the excitatory neurotransmitter dopamine relative to the depressant neurotransmitter serotonin. This can improve mental focus and delay the perception of fatigue.

While it won’t impede your progress or cause any adverse effects if you take an EAA supplement before your workout, the post-exercise use of EAAs can provide far more significant benefits.

Post-Workout EAA Supplements: The Bottom Line

Replenishing your body’s stores of EAAs after an aerobic workout can help to maximize the positive impact of your hard work. The post-workout benefits of EAA supplements are especially pronounced when taken the first hour after aerobic exercise.

EAAs produce a potent anabolic effect, serving as the key precursors for increased protein turnover. An increase in muscle protein turnover is the metabolic basis for improved muscle fiber functioning. In addition, EAAs increase the production and functioning of the mitochondria, the site in each cell where energy production takes place These responses can only be achieved with a formulation containing all of the EAAs, since all EAAs function as building blocks from which new proteins are formed.

While BCAAs alone are not effective, the optimal EAA formulation for post-aerobic-exercise supplementation should have a higher proportion of BCAAs in the total mixture than is represented in the composition of muscle protein in order to restore the BCAAS that were metabolized during exercise.

How to Use EAA Supplements to Boost the Effects of Aerobic Exercise