The Best Amino Acids for Energy

Which aminos help with energy production, muscle building, weight loss, sleep cycles, and more? Find out the difference between nonessential and essential amino acid supplements, plus the science behind how they work in the body.

When people supplement with amino acids, they’re usually looking for some very key boosts: muscle building, weight loss, and energy. Whether it’s energy to get through a workout or bodybuilding session at the gym, or energy that carries you through your daily activities (of which greater muscle strength and less body fat also help), amino acids are effective supplements for improving your health and physical performance. But which are the best amino acids for energy? Let’s explore some of the options.

The best amino acids for energy.

The Best Amino Acids for Energy

Here are some of the amino acids that have been proven to help increase energy, decrease muscle fatigue, and improve athletic performance.

1. Citrulline

Citrulline is a nonessential amino acid, meaning it is naturally produced in your body. However, people often supplement with citrulline to boost their exercise performance, mostly because one of citrulline’s uses is to increase blood flow to your body and muscle tissues. Citrulline does this by revving up your body’s production of nitric oxide, a vasodilator that relaxes the blood vessels and opens them up, allowing more oxygen and other nutrients to move through the body faster, thereby increasing energy and stamina.

This 2015 study found that taking citrulline supplements allowed cyclists to bike 12% longer than the placebo group, while this 2010 study showed that taking citrulline increased the amount of reps bodybuilders could do by 53% over the control group.

Citrulline is also known to help reduce muscles soreness and appears to be totally safe for use, with no adverse side effects reported up to 15 grams.

2. Beta-Alanine

Beta-alanine is another nonessential amino acid that improves muscular endurance, enhances anaerobic exercise capacity, and reduces muscle fatigue. Beta-alanine helps combat the acid buildup in your muscles during intense exercise (especially short bursts of energy like sprints or a single strength-training session). Increasing levels of beta-alanine could help improve your physical performance and prolong your endurance.

A brief yet effective pre-workout supplement, the one reported side effect of beta-alanine supplementation is a feeling of tingling skin if taken in high doses.

3. Branched-Chain Amino Acids (BCAAs)

The branched-chain amino acids are three of the nine essential amino acids: valine, leucine, and isoleucine. BCAAs are so-called because their chemical structures involve branching chains of molecules. Naturally found in high-protein foods like meat, fish, eggs, and plant sources of protein like beans and legumes, BCAAs and the other essential aminos are substances your body needs to consume, if not by food then by supplement.

Many athletes, bodybuilders, and fitness-minded folk will take BCAA capsules or powders to help enhance their workouts because these particular amino acids make up over 30% of our muscle protein. BCAA supplements have been studied and scientifically proven to help improve running endurance, reduce both physical and mental fatigue, and diminish muscle soreness after activities like running and weight training.

The only problem with BCAAs is that they are only a third of the nine essential amino acids needed to create new muscle, and that excessive amounts of BCAA powders taken without the other six essential aminos can lead to counterproductive catabolism—basically the cannibalizing of your muscle tissue to access those other amino acids. Not only does catabolism reduce your lean muscle mass, but it also damages your energy levels, because you’re wasting energy on destructive metabolism instead of the virtuous cycle of only using energy to build, repair, and maintain muscle growth.

4. Essential Amino Acids (EAAs)

Amino acids are the building blocks of protein in your body, and the essential amino acids are the ones you need to import from outside the body, because they cannot be synthesized within. EAA supplements contain not only the three branched-chain amino acids, but the other six as well: histidine, lysine, methionine, phenylalanine, threonine, and tryptophan. They help with everything from hormone creation, immune support, muscle building, metabolism regulation, and energy transport. Here are some of the most vital roles each essential amino plays in your body.

  • Valine: A branched-chain amino that stimulates the growth of new muscle and is actively involved in energy production.
  • Leucine: This branched-chain amino acid is used in both new protein synthesis, muscle repair, wound healing, blood sugar regulation, and the production of growth hormones.
  • Isoleucine: The final branched-chain amino, this isolated form of leucine (hence the name) is heavily concentrated in your muscle tissue where it aids muscle metabolism and energy regulation.
  • Histidine: This neurotransmitter is used to create histamine and is needed in digestion, sexual function, immune response, and for regulating your sleep-wake cycle (circadian rhythm).
  • Lysine: Used in hormone and enzyme synthesis, lysine also plays a major role in new protein creation, energy production, and the generation of elastin and collagen (which keep our joints, skin, and hair supple, making lysine one of the amino acids for anti-aging).
  • Methionine: This amino is important for tissue growth, zinc absorption, detoxification, and metabolism.
  • Phenylalanine: Precursor to the neurotransmitters dopamine, epinephrine, and norepinephrine, this amino also helps produce the other nonessential amino acids.
  • Threonine: Another contributor to elastin and collagen for anti-aging, threonine also aids in fat metabolism for energy usage.
  • Tryptophan: Most often thought of as the chemical in turkey which makes you sleepy, tryptophan regulates sleep, mood, appetite, and is needed to create serotonin (the “happy hormone”).

As you can see, all the essential amino acids are needed to build muscles and produce the fuel needed to use them, making each and every one an important amino acid for energy. The best supplements for improved energy should come with a whole host of EAAs.

The Energy Enhancement of Essential Amino Acids

Energy creation and expenditure is a cycle in the human body, requiring not only the generation of energy from food and body fat, but also the use of it to build and strengthen our muscles. Here is how supplementing with essential amino acids contributes to each aspect of the energy cycle.

Improve Exercise Performance

The branched-chain amino acids have been extensively studied to show they increase physical performance and reduce energy fatigue. A recent 2017 study found that BCAAs significantly improved muscle recovery and decreased the muscle soreness experienced by athletes over the placebo group in a 16-person trial. A 2017 review of eight other studies found that BCAAs across the board helped to promote muscle recovery and reduce delayed onset muscle soreness (DOMS).

Even leucine alone has shown an ability to increase strength performance in untrained, non-athletic men (although this increase is greatly limited by the availability of all the other EAAs)—that means amino acid supplements are a great place to start for those who are new to fitness.

Prevent Muscle Loss

When working out and when getting older, we lose muscle mass to other needs in the body. Though BCAAs alone cannot definitively preserve your muscle, and BCAAs without a balanced amount of the other essential aminos might cause catabolism as they seek the other ingredients they need to synthesize new protein, a more thorough amount of the essential amino acids have been shown to preserve muscle mass and prevent muscle breakdown.

This 2009 study of older adults who were on bed rest and susceptible to muscle atrophy demonstrated that 15 grams of EAAs helped maintain muscle protein synthesis, while the placebo group’s muscle synthesis decreased by 30%. Another 2009 study found equivalent results in older women who were able to preserve and even increase lean body mass with supplemental EAAs. When talking about amino acids for anti-aging, preventing age-related muscle wasting is a huge area of importance.

Promote Weight Loss

EAAs can be effective in stimulating fat loss, significantly decreasing the percentage of body fat in men over an 8-week study (the same effects have been shown in animal studies). While fat is, in a sense, a fuel source (the principle behind the ketogenic diet for example is to train the body to burn fat for energy almost exclusively), an excessive amount of fat, especially around your midsection, is not only dangerous to your cardiovascular health, but it’s also a lot more cumbersome weight to carry throughout your day, requiring extra energy that could be better spent. EAA supplementation can lead to better metabolism performance, greater muscle mass, and lower body fat all at once.

Amino Energizer

The best amino acid supplements should contain all the essential amino acids relevant to building muscle, producing energy, and losing excessive weight. The health benefits derived from the right aminos go beyond sports nutrition and into the realm of optimum nutrition for your longevity and quality of life. Check out Amino Co.’s own blend of balanced essential amino acids to see if it doesn’t boost your energy levels, your fitness performance, and your overall well-being.

Amino Acid Powder: The Top 10 Benefits

Learn about the difference between BCAAs and EAAs, plus the top 10 health benefits of amino acid powders and when it’s best to take them for optimal workout performance. 

Amino acid powders are supplements taken much the same way as protein powders like creatine and whey protein. They are important to muscle building for a very simple reason: they are the bricks and mortar of your muscles, and without them your body cannot synthesize new muscle for repair or growth.

Many people are familiar with branched-chain amino acids (BCAAs), used by bodybuilders and the fitness-minded alike, but BCAAs are only three of the nine essential amino acids (EAAs) required for muscle creation. For more on the difference between BCAA and EAA supplements, plus the benefits you can expect from supplementing with amino acids, read on.

Top 10 benefits of amino acid powders.

BCAAs vs. EAAs

The three BCAAs are valine, leucine, and isoleucine, and they make up about 35% of our muscle protein. They are isolated for supplementation because they reduce the amount of protein breakdown that occurs due to vigorous workouts, and they help preserve the muscle’s stores of glycogen, which is the muscles’ quickest energy source. Leucine is the big player among the three, and it’s also one of the main components of whey protein.

However, the reason people sometimes consume BCAAs instead of whey protein is because when these amino acids aren’t bound up with other components, they can digest and absorb faster, giving them a bigger impact as a workout supplement. The reason some people take complete EAA supplements over BCAAs is similar: you can’t increase your muscle mass without all nine of them, meaning that a full court of EAAs has an even greater positive impact on your fitness goals.

The essential amino acids include:

  • Phenylanine
  • Valine
  • Threonine
  • Tryptophan
  • Methionine
  • Histidine
  • Isoleucine
  • Leucine
  • Lysine

If you ever need a mnemonic device to remember them (taking a biology quiz maybe?), notice that in this order, the first letter of each essential amino acid spells out Pvt. T.M. Hill: good old private T.M. Hill can help you remember your EAAs, just as Roy G. Biv can help you remember the order of the colors in the rainbow (red, orange, yellow, green, blue, indigo, and violet).

Essential amino acids are so called because they’re needed in your body, but your body can’t create them itself, so it’s essential that you gain them by ingesting them.

Essential amino acids are indispensable, and there are six more amino acids that are considered conditionally essential—arginine, cysteine, glycine, glutamine, proline, and tyrosine. Their creation in the body isn’t always possible (like when we are infants). The rest of the amino acids are made in-house by your body.

The Top 10 Benefits of Amino Acid Powder

When your goal is to build lean muscle with your workouts, protein is key, and you can’t have protein without amino acids. Here are the best benefits you can expect from taking amino acid powder as a workout supplement.

1. Balanced Dosages

The great thing about getting your amino acids in powdered supplement form is the same perk you get when using meal replacement shakes for weight loss: it comes pre-measured, guaranteeing that you receive the proper ratio of amino acids every time. Even high-quality protein supplements don’t always take into account the ideal ratio of amino acids that are scientifically required for building new muscles, so when shopping for the right workout aid, be sure to purchase a comprehensive and balanced amino acid powder, one that has exactly what you need in precisely the right amounts.

2. Improved Muscle Growth

Leucine especially shines here, as it has been clinically shown to boost muscle protein synthesis after physical exercise. That window of post-workout recovery is when your muscles are wide open for material to rebuild the cells that were damaged during exercise, and create even more muscle in preparation for the next workout. For more on the best time to take amino acid powder, read (or skip!) to the end of this article.

3. Increased Endurance

Amino acid supplements alter the way your body uses fuel, namely by changing the way you burn carbs and fat. Athletes like sprinters who require short bursts of strong energy have to deal often with glycogen depletion from their muscles. There’s only so much glycogen your muscles can hold, and if you use it up too quickly, you’ll run into fatigue or exhaustion and will have to cut your workout short. With amino acid supplementation, however, glycogen stores are better protected, as was seen in this 2011 study involving 7 men who were put through a workout designed to sap their glycogen supply. Those given amino acids instead of a placebo had a 17.2% increase in how long it took them to hit the wall of exhaustion.

4. Better Fat Burning

Amino acids protect glycogen stores by burning fat instead of glycogen for fuel. Amino acids help to retrain your body’s metabolic processes. For instance, the amino acid L-carnitine has been shown to increase fat loss without any other changes being made to your diet or exercise routine. If you’re on a low-carb diet like the ketogenic diet, even better: your body will learn to access your fat stores for energy as much as possible, because it can’t get the quick energy from carbohydrate intake.

5. Reduced Fatigue

Piggybacking off the above-mentioned benefits, amino acids have the ability to prevent the mental fatigue that can accompany really long workouts. When your amino acids are low, such as during a grueling workout, your body works to produce more, specifically tryptophan. And when the amino acid tryptophan gets too low, its production leads to feelings of mental fatigue and tiredness (it’s why turkey is considered sleep-inducing—the tryptophan in the meat!). If you’re supplementing with the proper amount of amino acids, this process never has to begin, and thus there is no extra tryptophan running around making you feel depleted and tired.

6. Increased Focus

Without extra tryptophan making you soporific, your mental focus is able to sharpen. Amino acid supplements have been shown to boost your short-term memory and mental processing abilities, and so are particularly valuable in competitive sports or contests, when fast strategizing can help you win.

7. Muscle Sparing

When you workout, you’re causing little micro-tears in your muscles. It’s necessary damage, sort of like how you need to be exposed to viruses to develop an immunity to them (it’s the reasoning behind vaccines, which contain deactivated viral cells).

Usually the muscle damage is minimal, just enough to stimulate your body into sending resources to repair and then rebuild bigger, better, and stronger muscles than ever before. Sometimes, however, muscles are broken down out of desperation for energy. This is catabolism, a destructive form of metabolism, and those who work out hard, especially bodybuilders, know to guard against it.

During the day you can feed your body energy, but what is your body eating while you sleep? In some instances it resorts to cannibalizing itself in a sense, breaking down the muscle you’ve worked so hard to build. Amino acids can help prevent catabolism by protecting your muscle fibers from taking too much damage in the first place; plus you can supplement right before going to bed (but more on when to take amino acid powders below).

8. Improved Post-Workout Recovery

Free amino acids in an amino acid powder are quickly absorbed, which helps increase your muscle protein synthesis rate and shorten your post-workout recovery time. The muscle soreness that used to linger can be dispatched much quicker with proper amino acid supplementation. Quicker recoveries mean you can work out again sooner, putting you in a virtuous cycle (the opposite of a vicious cycle), where workout and recovery revolve around one another in beneficial harmony.

9. Reduced Muscle Soreness

Delayed onset muscle soreness (DOMS) can be a real hinderance to your fitness goals, but because amino acids help protect your muscles better and rebuild them quicker, they’ve been scientifically shown to reduce muscle soreness.

10. Improved Athletic Performance

When you count up all the ways amino acid supplements aid you and your muscles, the finally tally shows that they improve your overall athletic performance in more ways than one. Smarter, better, faster, stronger: amino acid powders can help you be all of these things with just a few scoops a day.

When to Take Amino Acid Powder

The fourth edition of Essentials of Strength Training and Conditioning states that our muscles are particularly receptive to amino acid supplements within the first 48 hours after a workout. Likewise a study published in Frontiers in Physiology asserts that 5.6 grams of just BCAAs ingested after strength training exercise leads to a 22% increase in muscle protein synthesis. Similarly the Journal of the International Society of Sports Nutrition reminds us that you need a healthy supply of all the essential amino acids to stimulate muscle protein synthesis, which is why we recommend a comprehensive EAA blend when seeking to build muscle tissue.

A number of studies have shown that all nine EAAs play important roles in muscle growth and repair, and when it comes to the timing of when you should consume your essential amino acid powder supplement, you almost can’t go wrong: pre-workout, intra-workout, and post-workout, plus another helping before bed if you’re concerned about catabolism. While some forms of workout will require more or less supplementation regarding dosage amounts, pairing amino acid supplementation with a high-protein diet will have you covered.

The Amino Advantage

In your quest to build lean muscle mass through working out and eating right, consider adding a high-quality, gluten free, non-GMO amino acid powder like the one we offer here at Amino Co. Amino acid powders give you an extra advantage in all your workout and sporting goals.

BCAA vs. Creatine: What You Need to Know

BCAA vs. creatine: a comprehensive look to help you decide which you should choose, or whether you’d rather utilize a product that combines the two supplements for better energy, muscle strength, and protein synthesis.

If you spend enough time in the gym, you will eventually run across this question: BCAA vs. creatine, which supplement do you prefer? Before you can answer that question, you’ll need the information behind both BCAAs and creatine: what are they? What are the upsides and downsides to each? How can they help build muscle? Can they both be taken together? You’ll find the answers to all of those questions here, plus learn about the one ultimate supplement that perfectly marries the two together, so you never have to compromise for imbalance in your muscle-building nutrients.

BCAA vs. creatine: a comprehensive look.

What Is BCAA? What Is Creatine?

We’ll start with the definitions, and then move on to the differences between these two supplement options.

BCAA: Branched-Chain Amino Acids

A BCAA supplement is made up of branched-chain amino acids, specifically the three amino acids leucine, isoleucine, and valine. There are a total of nine essential amino acids, essential because you must eat or otherwise consume them to get them (other amino acids are produced in-house by your body). Leucine, valine, and isoleucine are essential amino acids.

“Branched-chain” refers to the molecular structure of these three specific amino acids. The chemical bonds branch off of the main structure.

Studies have shown that BCAAs help reduce muscle damage and soreness in post-workout recovery.

While it’s possible to get a sufficient amount of the BCAAs from your diet, for those who work out intensively, and/or for those on specific diets aimed to lose weight, it might be difficult to get the right amino acid balance, which is why some will chose a BCAA supplement in the hope that it will round out their nutrients. However, it should be noted here that muscle synthesis cannot take place without all nine essential amino acids, so a complete essential amino acid (EAA) supplement is preferable to a BCAA one—you cannot build muscle with only a third of the necessary ingredients.

To cut calories without having a negative impact on protein intake for muscle mass is important, and BCAAs are often taken to try to ensure there’s no interruption to protein synthesis while dieting. Even if weight loss isn’t your goal, the BCAAs gained from taking a complete EAA supplement might still help in that department by contributing to appetite control.

BCAAs have similar benefits to a whey protein shake, but with fewer calories. Moreover, the amino acid leucine is one of the two specifically ketogenic amino acids, another way that BCAA supplements contribute to fat loss (the ketogenic diet is all about burning off fat, and doing it both quickly and safely).

BCAA supplements are perhaps best suited for CrossFitters, bodybuilders, or rowers, but again, they are only a third of the essential amino acids, all of which are necessary for muscle building.

BCAA Quick Facts

  • BCAAs provide three of the nine essential amino acid building blocks of muscle tissue.
  • BCAAs help protect lean muscle and guard against muscle wasting.
  • BCAA supplements are a source of longer-term energy, and can help reduce exercise fatigue.
  • BCAAs help promote fat loss via appetite suppression and increased metabolism for burning calories.
  • BCAA supplements provide higher strength gains than whey protein does.
  • There are no harmful side effects reported from BCAA supplementation.

Creatine: The Energy Protein

Creatine is creatine monohydrate, the protein found in animal sources of meat like fish, poultry, pork, and red meat. Creatine contains two different amino acids, arginine and methionine, of which methionine is essential.

Unlike the weight-loss potential in BCAA supplements, taking creatine can lead to initial weight gain, as it causes some water retention in the muscles. Likewise, if you’re not drinking enough water while taking creatine, cramping can occur, meaning it’s more important than ever to stay hydrated while working out.

Researchers have stated that creatine might help lessen the effects of osteoarthritis, slowing the loss of bone mass as you age. Another unique benefit of creatine is its ability to deliver the rapid energy that is needed during fast muscle contractions (when sprinting, for example). That means creatine gives you longer endurance, which means more reps, which means more muscle growth. This is why creatine is best suggested for powerlifters or sprinters, and why it’s a part of our unique EAA blend (see below for further details).

Creatine Quick Facts

  • Creatine breaks down into phosphocreatine (CP), which provides rapid energy for muscle contractions.
  • Creatine causes the release of the anabolic hormone IGF-1, used in promoting muscle growth.
  • Creatine is a quick source of muscle energy, allowing for more reps.
  • Creatine use aids long-term bone strength for weight trainers.
  • Creatine increases strength during resistance training by up to 20%.
  • Some water retention and cramping is reported with the use of creatine, but the effects are short term.

BCAA vs. Creatine: Which Should You Use?

If you’re here to make a choice, now’s the time to review your fitness goals and how each of these products might influence them. Research suggests that BCAAs help to increase muscle mass for those doing resistance training. If your diet is low on protein intake, say if you’re vegetarian or vegan, BCAA supplements are a great way to promote muscle protein synthesis, but remember that they are also only a partial supply of the amino acids you need for muscle building.

Likewise, a study also showed that muscle strength increased up to 8% for those using a creatine supplement while resistance training. Creatine can provide rapid energy when the usual muscle cell energy supply of adenosine triphosphate (ATP) is slow to regenerate, and it goes a long way towards the kind of strength building and increase to muscular force that might be preferred by powerlifters.

Both supplements aid muscle recovery, both contain at least one essential amino acid, both help drive protein synthesis, both of them are good to take as pre-workout supplements for their benefits, and honestly, unless you have a specific reason to not take one of them, you may be thinking that you want to take both. Well good news for you then, because you can! In fact, we recommend that you do.

BCAA and Creatine Together

You may have noticed that there was no overlap between the amino acids from BCAA supplements and creatine supplements, which means taking both will not overdose you on any one amino acid. Rather than think of them as enemies in some competition for supplement supremacy, BCAAs and creatine can be two valuable players on the same team: your team. Nothing bad will happen to you if you combine them (they’re not baking soda and vinegar in a third grader’s science fair volcano or anything), and since they both aid sports performance, boost muscle building, help with fat loss, and ease muscle recovery, when taken together you may see improved results in all of those categories.

However, if you’re after a full roster of the essential amino acids, there are amino acid supplements that include all three BCAAs, plus the other muscle-building EAAs. Whether you’re looking into supplementation because you’re lifting weights or attempting to lose body fat or both, a protein powder with only partial, unbalanced amounts of amino acids just won’t do the trick.

A Complete EAA Blend

When it comes to muscle-building supplements, our blended EAA formula not only contains eight of the nine essential amino acids, including the BCAAs, but it also supplies them with the energy of creatine and the steady amino acid digestion that comes from whey protein supplements (derived from milk).

This supplement is scientifically proven to increase human muscle growth and can help prevent muscle breakdown in the elderly. It was also designed to contain the exact ratio of amino acids needed to build muscles without overtaxing your body with excessive or unnecessary amounts of any one.

When building muscle, you don’t want to show up with a partial supply of the building blocks of protein. Instead, you want a comprehensive EAA supplement that helps all the work you do weight training at the gym to pay off. Instead of a dose of BCAAs here or a dash of creatine there, we recommend you get the most out of all of the above with our combination of EAAs with creatine and whey protein support. If the question is BCAA vs. creatine, the real answer is the Amino Company’s blends: for balance, for building, for the best of both worlds and more.

Most Popular Supplements for Muscle Growth

Learn the chemistry behind the traditional top supplements for muscle growth, and find out about the newest and most comprehensive supplement that’s about to revolutionize muscle building.

If you’re looking for supplements for muscle growth, you’ve probably already noticed that it’s a pretty crowded field. Different proteins and combinations and timing strategies get discussed, and before you know it you feel like you need about half a degree in chemistry just to build muscle at the gym! We’re streamlining the relevant information on muscle-building supplements, their pros and cons, so you can decide on the best supplements for your own fitness goals. If you’re in a rush, skip to the end, because there’s a new supplemental option that combines the best muscle growth nutrients you’ve ever known, all in one complete, balanced formula that will best all the rest. Read through to learn about the ideal muscle-building combo, a powerful protein trinity.

The First Steps Towards Muscle Building

Getting the most out of your workout involves taking a few first steps before you can start targeting muscle gain specifically. The first steps after taking up regular exercise are:

While supplements are not mandatory to reach these goals, they can be excellent aids to quicken your progress and maximize your protein intake without bringing unpredictable calories to your diet. Next up we’ll discuss the top supplements for muscle growth that you can choose from when attempting to gain muscle mass, and reveal a cutting-edge, scientifically-backed newcomer to the muscle-building supplement world.

Traditional Top Supplements for Muscle Growth

Over and above eating well and lifting weights, here are some protein and muscle-building supplements you can use to augment your workout goals, some of them more effective than others.

Top supplements for muscle growth and bodybuilding.

Carnitine

Carnitine is the general term for a group of amino acid compounds that include L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine. Carnitine is a transporter that moves long-chain fatty acids into mitochondria, where they’re oxidized or burned for energy.

A popular supplement for fat-loss, carnitine can also aid muscle growth by increasing blood flow to muscles, lessening muscle soreness, and increasing nitric oxide production, all of which improve your post-workout recovery. The combination of these benefits makes carnitine a strong asset for energy-boosting while you’re building muscles through exercise, especially when utilized in pre-workout and post-workout shakes. Though it doesn’t directly contribute to muscle building, it does provide valuable energy assistance, and improves performance during endurance athletics.

Pros

  • Aids athletic endurance by providing energy transport.
  • Helps ease muscle soreness and improve post-workout recovery.

Cons

  • Does not directly increase muscle, but instead aids in workout energy.
  • Carnitine is only a peripheral aid to individuals working to build muscle via exercise.
  • Carnitine would need to be taken alongside direct protein or amino acid supplements to be most effective.

Whey Protein Powder

A milk protein derived from whey, which is the watery part of milk that separates from the curd, whey protein is an excellent supplement affecting protein synthesis. With a high level of branched-chain amino acids or BCAAs, and including some amount of all nine essential amino acids (EAAs), this protein supplement digests relatively quickly and can help with rapid muscle building.

Whey protein can help increase blood flow due to its content of peptides, and is regularly consumed by bodybuilders immediately after their training sessions (within the hour). When choosing a whey protein, it’s recommended that you find a powder containing whey protein hydrolysates, which are proteins broken down for faster digestion.

Pros

  • Whey protein is a complete protein, containing all nine essential amino acids.
  • Whey protein is high in the branched-chain amino acids (BCAAs).

Cons

  • While whey protein is a fast-absorbing whole protein, free-form amino acids can be absorbed much more quickly.
  • Whey protein’s amino acid content is not optimally balanced, and a properly formulated essential amino acid supplement can have 3 times the effectiveness rate as a whey protein powder supplement alone.

Glutamine

Glutamine is an amino acid that not only helps build muscles by increasing the levels of the essential amino acid leucine in muscle fibers, but it also helps fight against muscle breakdown, and has been shown to play a significant role in protein synthesis.

Incidentally, glutamine can also be recommended for those with digestion issues (diarrhea or constipation), anxiety, cravings for sugar and/or alcohol, and those with poor wound healing.

Pros

  • Valuable as a precursor to the essential amino acid leucine.

Cons

  • Glutamine aids only one of the nine essential amino acids needed for muscle building, and so is far from being the most effective muscle-building supplement.
  • Glutamine is unnecessary if you’re taking a complete blend of essential amino acids.

Casein Protein Powder

Casein is the other milk protein that is derived from the curd of the milk and not the whey. Casein has a slower digestion rate than whey protein does, which makes it an excellent protein to take before bed, as it digests while you sleep and helps to prevent catabolism (which is to say destructive metabolism, a kind of self-cannibalism the body sometimes resorts to for energy).

Because increased calorie intake is also needed to build muscle, casein can help by being less filling than whey, allowing you to consume more alongside it. However, it’s also suggested that taking a combination of whey (or better yet free-form essential amino acids…read on!) and casein after a workout can help with muscle protein synthesis better than taking either one of them alone. Be advised that a casein protein product with micellar casein is the slowest-digesting form of casein readily available, and is your best bet when buying it as a supplement.

Pros

  • Casein protein has a slower digestion rate than whey, which can help prevent catabolism during sleep.

Cons

  • Works best when combined with stronger protein supplements like whey protein or free-form essential amino acids.

Beta-Alanine and Carnosine

Beta-alanine, an amino acid and key component of the dipeptide carnosine, aids in increasing carnosine levels and thus heightening muscle strength and muscle endurance. Higher levels of carnosine also increase the force of muscle contractions, and combining it with creatine (next on the list) has the greatest effect on losing body fat and gaining lean tissue, as was seen when the two were studied during a 10-week resistance training program conducted with collegiate football players.

Pros

  • Carnosine contributes to muscle endurance, leading to more powerful workouts, which can then translate to increased muscle.

Cons

  • Carnosine does not directly build muscle, but instead helps aid in workout endurance.
  • Carnosine is most effective in combination with proteins like creatine or free-form amino acids, and so is best as peripheral support for muscle building.

Creatine

Popularized as a workout supplement in the 1970s, creatine is made up of three amino acids—glycine, arginine, and methionine—and is vital for supplying the energy for muscular contraction. Creatine can be found in the forms reatine alpha-ketoglutarate (AKG), creatine monohydrate, and creatine malate. Creatine has been shown to increase the levels of insulin-like growth factor-1 (IGF-1) in resistance-exercise training, which is essential for stimulating muscle growth.

Creatine is converted to phosphocreatine (CP) in the body, which then provides energy for explosive exertions like heavy weight lifting or sprinting. The creatine-phosphocreatine system provides an increase in energy supplied to muscle cells when your body is using more ATP (adenosine triphosphate) than is being regenerated in the cells’ mitochondria. This increases your athletic endurance.

Pros

  • Provides energy for increased exercise performance, especially when you’re using more ATP than the mitochondria of your muscle cells can regenerate.
  • Creatine helps stimulate muscle growth.

Cons

  • Creatine is not most effective when taken alone, but is instead at its best when paired with an essential amino acid (EAA) supplement, where it will help provide the energy needed for increased muscle protein synthesis.

Nitric Oxide Boosters (Arginine)

Nitric oxide (NO) in the body serves to dilate blood vessels, thus allowing better blood flow to muscles, providing them with energy, nutrients, water, anabolic hormones, and oxygen—everything your muscles need to function, grow, and thrive. Nitric oxide boosters do not contain nitric oxide, but instead provide it via the amino acid arginine, which the body converts into nitric oxide.

Arginine supplements are often marketed based on their association with muscle growth, increased muscle strength, and loss of bodyweight. However, we recommend supplementing with citrulline to increase arginine, as arginine supplements don’t produce significant increases in blood arginine concentrations due to the liver‘s effectiveness at clearing absorbed arginine. Citrulline, on the other hand, is converted into arginine by the kidneys, and the arginine is then released into the bloodstream; this more effectively increases your arginine levels. Additionally, there are no adverse effects associated with citrulline supplementation, while arginine consumption can sometimes lead to gastrointestinal discomfort.

Pros

  • Arginine in the bloodstream leads to more readily available amounts of nitric oxide, essential for muscle functioning.

Cons

  • Counterintuitively, arginine supplements are often ineffective at supplying useable arginine to the bloodstream.
  • Instead citrulline is recommended to supplement for an effective increase in arginine, and can be taken alongside or included in EAA and protein supplements for optimal muscle performance.

ZMA (Zinc, Magnesium Aspartate, Vitamin B6)

Supplementing the minerals zinc and magnesium aspartate along with vitamin B6 is sometimes important to bodybuilders because they become depleted during intense training and need to be specifically replaced. These nutrients are necessary for maintaining proper sleep and hormone levels, as testosterone particularly can be compromised by intensive training.

Athletes who take ZMA have been shown to have increased levels of IGF-1 and testosterone, both of which have an influence on muscle gains. ZMA is recommended to be taken before bed on an empty stomach, to allow for better uptake and to help improve sleep quality and the muscle recovery that sleep provides.

Pros

  • Can help correct vitamin and mineral deficiency caused by intensive weight training.

Cons

  • ZMA supplementation does not lead to direct muscle growth, but can be taken as needed alongside free-form amino acids or traditional protein contributions like whey or creatine, depending on your workout style and your body’s needs.
  • Not everyone will need the extra supplementation of ZMA.

HMB (Beta-hydroxy beta-methylbutyrate)

Beta-hydroxy beta-methylbutyrate or HMB is a molecule derived from the processing of the essential amino acid leucine, and helps protect against muscle protein breakdown. HMB is often recommended only for those who are beginning weight-training exercises, as the scientific results seen in those who are more experienced with muscle training are less significant. This is due to the fact that HMB is heavily reliant on a steady and abundant supply of EAAs to be effective. When the EAA supply dips down, so does the effectiveness of HMB; it cannot work alone.

Pros

  • HMB supplementation can be good for resisting extreme catabolic states, such as in individuals with critical wasting illnesses.

Cons

  • HMB without an excess supply of EAAs is only marginally effective.
  • EAA supplementation is also needed to derive maximum benefits from HMB supplementation.

Branched-Chain Amino Acids (BCAAs)

The branched-chain amino acids are a subcategory of essential amino acids, and are designated by the molecular structure of leucine, isoleucine, and valine. BCAAs make up 14% of the amino acids that reside in your muscles, and it’s been shown that taking a supplement of BCAAs during resistance-training exercise increases muscle strength, fat loss, and lean mass.

However, while research shows that leucine in particular stimulates muscle protein synthesis, and that together these three amino acids diminish cortisol (a catabolic hormone), increase energy, and reduce delayed-onset muscle soreness, BCAAs when consumed alone are not fully effective. All nine essential amino acids are needed to make new muscle, and in fact, the the rate of muscle protein synthesis is directly affected by the availability of all your essential amino acids—the more you have, the faster your rate of muscle synthesis, and the fewer you have, the slower the rate. Because of this, research actually shows that BCAAs when taken alone have little to no effect on the rate of muscle protein synthesis in humans.

Pros

  • BCAAs are valuable amino acids that can be taken to help some aspects of muscle building.

Cons

  • BCAAs are only three of the nine essential amino acids, and all essentials are needed to create new muscle.
  • BCAAs have little to no effect on muscle protein synthesis when taken alone.

An Essential Amino Acid (EAA) Blend: The New Top Muscle Growth Supplement

If BCAAs ever sounded good, you’ll probably be more interested in a complete EAA supplement. Our unique EAA supplement is an ideally proportioned blend that combines the strengths of whey protein, creatine, and the eight essential amino acids that contribute directly to muscle growth. With our EAA blend, you’ll not only get the BCAAs mentioned above, but also a full cocktail essential amino acid supplement. It contains the key factors that make whey protein and creatine effective too, giving you the best of every top effective traditional supplement on the market.

EAAs and Muscle Protein Synthesis

The human body is made up of about 20% protein, and amino acids are used to form our muscles, tissues, and organs (not to mention the hormones needed for cognitive and physiological function). The key to our muscle-building product that helps make it more effective than other supplements, and even some dietary sources of essential amino acids, is its absorption rate and digestibility.

The EAAs derived from dietary proteins have to be digested first and then absorbed, while free-form amino acids are absorbed more quickly and completely. With eight of the nine essential amino acids (minus tryptophan which is not necessary to supplement for muscle protein synthesis), the amounts of EAAs are maximized more than any naturally occurring protein can deliver.

EAAs with Whey Protein’s Support

While free-form EAAs provide faster absorption, an intact protein like whey provides for a longer absorption period, sustaining the supply of EAAs after the rapid absorption of the free-form EAAs. Designed to work in concert with one another, our muscle-growth supplement combines its EAA profile with a balanced inclusion of whey protein for steady, ongoing support of muscle protein synthesis.

EAAs and Creatine’s Energy

Because creatine-phosphate provides the energy for sudden bursts of physical activity like lifting heavy weights or sprinting, it’s included in the Amino Co.’s technology to provide the energy needed to convert EAAs into muscle via muscle protein synthesis. Instead of waiting for the mitochondria of muscle cells to metabolize ATP for energy, creatine covers the time gap when needed, completing the full circle required for ideal muscle building: the rapid essential ingredients, the long-haul supply, and the energy to put them to use.

The Amino Company Advantage

Our product is a unique, patent-pending blend of essential amino acids, whey protein, and creatine that outperforms all other supplements in increasing muscle mass. Good for increasing strength in the elderly and easy to include in drinks or smoothies, Amino Co. supplements are scientifically proven to be effective in muscle protein synthesis over any other supplement, food, or protein choice currently available.

The ABCs of Muscle Growth

On a first glance at muscle growth supplements, it looks like an alphabet soup of vitamins and molecules and chemistry notes, but the more knowledgeable you become about your own body’s strengths and needs, the closer you’ll approach a PhD’s level of understanding when it comes to which supplements best support your goals. Effectiveness is key, bolstered by practical results that can be not only felt, but also scientifically proven. In the end, you can see which supplement brings you the greatest value.

The strongest performers from the traditional list of muscle growth supplements have been brought forward to the new frontier: an EAA blend that brings the best of everything essential to building and maintaining new muscle. The Amino Company provides the full circle of quick, long-lasting, and energized EAAs for muscle building. When you take our unique blend, you’re guaranteed to have an optimally balanced formula designed specifically for human muscle growth (and not lab animals). With the Amino Co. on your team, you can reach higher heights of strength faster and more effectively than ever before!

What Are the Best Muscle Recovery Foods?

Wondering what muscle recovery foods are good for prevention and relief of delayed onset muscle soreness? This comprehensive list of foods full of healthy fats, amino acids, and natural sugars will support your workout and recovery goals.

After starting a new workout, you’re in for some growing pains. Delayed onset muscle soreness or DOMS can affect anyone, from those new to working out to elite athletes incorporating different exercises into their routines. Whenever you push your muscles, either with unfamiliar exercises or longer durations, you’re creating microscopic tears to the muscles, which then cause stiffness, soreness, and pain. Are sore muscles a good sign? Yes, in a sense, because it means you’re using your muscles in new ways that will eventually lead to a better fitness profile. But don’t fret! Eating muscle recovery foods can help ease the discomfort and may even help decrease muscle soreness in the first place.

Using food as your method of recovery and prevention may truly be the best road to take. The other suggestions to help muscle recovery either take extra time or come with other risks, and none of them can get in front of DOMS before it starts. Getting a massage after every workout would be great, but do you have the time, the money? Rest and ice packs are perfectly reasonable options too, but it’s the rest that might bother you if you’re really excited about a new workout and seeing results. Do you really want to take a couple of days off after every workout to let your muscles recover? It might not be a bad idea, but with the right foods pre- and post-workout, it might not be necessary either.

The last refuge to treat the ache and pain of muscle soreness is to use painkillers. Whether it’s over the counter fare you’d take for any pains (a wincing headache for example, or to relieve menstrual cramps), or prescription painkillers meant for more serious pains (a wrenched back or dental surgery). And these pain killers come with health-compromising side effects that are best avoided.

So what can you eat that will make a difference? Here are some foods you might want to include on the menu on gym days.

 Muscle recovery foods for prevention and relief.

Muscle Recovery Foods

Whether for their protein content, iron content, anti-inflammatory properties, or amino acids, these foods can help your muscles heal faster.

Cottage Cheese

Cottage cheese has around 27 grams of protein per cup, and is often a regular food in the fitness community for those without any dietary restrictions surrounding milk products. In fact, the casein protein found in cottage cheese curds (as opposed to the whey protein found in watery milk) are often isolated and used as a workout protein supplement. As a slow-digesting protein, casein can help build and rebuild muscle while you sleep if it’s your last snack before bed.

The essential amino acid leucine is also present in cottage cheese, and comprises around 23% of the essential amino acids in muscle protein (the most abundant percentage of them all). Foods with leucine can help you build muscle by activating protein synthesis, and the faster you rebuild your muscle, the faster your muscle repair and workout recovery!

Eat it plain, or combine cottage cheese with some of the other recovery foods on this list to stack the benefits. Cottage cheese can even be used in baked goods and pancakes or included in protein shakes—don’t be afraid to get creative.

Sweet Potatoes

Adding sweet potatoes to your post-workout meal can help replenish your glycogen stores after a tough workout. Sweet potatoes are a great source of vitamin C and beta-carotene as well, and are loaded with fiber which helps to control appetite and maintain healthy digestion and build muscle.

Sweet potatoes can be baked whole in the oven or on a grill, cut into fries, spiced with cinnamon, or made savory with garlic powder and pepper. Enjoy them at the dinner table or on the go: a baked potato wrapped in foil can join you just about anywhere.

Baking Spices

Speaking of what you can put on sweet potatoes, it turns out some baking spices are good for post-workout recovery as well. Not so much in the form of gingerbread cookies or cinnamon rolls, but a study showed that cinnamon or ginger given to 60 trained young women (between the ages of 13 and 25) significantly reduced their muscle soreness post-exercise. If you’re already having a sweet potato, make it a little sweeter with some cinnamon, add it to oatmeal, or put some in your coffee for the extra boost.

Coffee

Did we just mention coffee? Good news: coffee’s on the list too. Research suggests that about 2 cups of caffeinated coffee can reduce post-workout pain by 48%, and another study showed that pairing caffeine with painkilling pharmaceuticals resulted in a 40% reduction of the drugs taken. If you do need pharmaceutical pain relief, maybe coffee can help you minimize just how much you take—caffeine is a much less dangerous stimulant than pain pills.

Turmeric

Another spice on the list, turmeric contains the compound curcumin, which is an anti-inflammatory and an antioxidant, and has been shown to be a proven and reliable pain reliever. Whether it’s helping you with delayed onset muscle soreness or pain from an injury (workout-related or otherwise), turmeric eases both pain and swelling by blocking chemical pain messengers and pro-inflammatory enzymes.

As with the other spices, it can be easily added to baked goods, to coffee, and to oatmeal. With its beautiful golden color, you can even make what’s called “golden milk” or a turmeric latte by combining 2 cups of warm cow’s or almond milk with 1 teaspoon of turmeric and another teaspoon of ginger, and then sip your muscle soreness away.

Oatmeal

Speaking of oatmeal (and isn’t it nice that so many of these ingredients can be easily combined?), it, too, can help relieve muscle soreness. This complex carb gives you a slow and steady release of sugar, along with iron needed to carry oxygen through your blood, and vitamin B1 (thiamin), which can reduce stress and improve alertness. This is why oatmeal is a great way to start the day, but since it also includes selenium, a mineral that protects cells from free-radical damage and lowers the potential for joint inflammation, it’s a great food for those in high-intensity workout training as well (like, up to Olympic level training).

Use oatmeal as a daily vehicle for other healthy ingredients, including the spices on this list, and enjoy its reliable benefits.

Bananas

Easily sliced into oatmeal, included in smoothies, or eaten alone, not only are bananas a healthy way to replace sweets (frozen and blended they can even make a delicious ice cream alternative), bananas are also a great way to get much-needed potassium. Research suggests potassium helps reduce muscle soreness and muscle cramps like the dreaded “Charley horse” spasm that contracts your muscle against your will and might not let up until it causes enough damage to last for days. A banana a day could keep the Charley horse away, and is particularly delicious (and helpful) when paired with its classic mate: peanut butter.

Peanut Butter

The healthy fats and protein found in nut butters like peanut or almond butter can help repair sore muscles. A reliable source of protein for muscle building, with fiber for blood pressure aid, vitamin E for antioxidant properties, and phytosterols for heart health, peanut butter offers up a ton of benefit and is easy to eat anywhere. Make a sandwich, use it to help bind together portable protein balls filled with other ingredients, add it into smoothies, or just eat it from the jar with a spoon (no one’s judging).

Nuts and Seeds

If you’re a fan of protein balls, then you’re well acquainted with nuts and seeds, which are great additions to these protein-rich foods. While providing essential omega-3 fatty acids to fight inflammation, various nuts and seeds can provide you protein for muscle protein synthesis, electrolytes for hydration, and zinc for an immune system boost. Something as simple as a baggie full of almonds, walnuts, pumpkin, and cashews can help maximize your muscles. Mixing in seeds (sunflower, chia, pumpkin) adds a healthy density that can curb your hunger and satisfy your appetite for longer. They’re small but powerful assets in quick muscle recovery.

Manuka Honey

This is not your grocery store honey in its little bear- or hive-shaped bottle. Manuka honey comes from the Manuka bush in New Zealand, with a milder flavor than that of bee honey and a much thicker texture. It’s anti-inflammatory and rich in the carbs needed to replenish glycogen stores and deliver protein to your muscles. Drizzle it over yogurt or stir it into tea to gain its benefits.

Green Tea

Green tea is particularly helpful for muscle recovery purposes. With anti-inflammatory antioxidants, it makes an excellent pre- or post-workout drink to prevent muscle damage related to exercise, and also helps you stay hydrated.

Cacao

Cacao has high levels of magnesium, antioxidants, and B-vitamins, which reduce exercise stress, balance electrolytes, and boost immunity and energy levels. The antioxidant flavanols in cacao also help up the production of nitric oxide in your body, which allows your blood vessel walls to relax, lowering blood pressure and promoting healthy blood flow. Adding cacao powder to your high-quality protein shakes or a glass of cow/almond/coconut milk post-workout will bring you its benefits.

Tart Cherries

Tart cherry juice has been shown to minimize post-run muscle pain, reduce muscle damage, and improve recovery time in professional athletes like lifters, according to the Journal of the International Society of Sports Nutrition. Enjoy tart cherry juice as a drink, or include the dried fruit as a part of your own muscle-building trail mix with the nuts and seeds discussed above. It’s not the only fruit or fruit juice you might include either. The nutrients in fruits like oranges, pineapples, and raspberries can also help speed up your recovery.

Salmon

Rich with anti-inflammatory omega-3 fats, muscle-building protein, and antioxidants, salmon is an extremely efficient post-workout food. Not an option if you are vegan or vegetarian, of course, but for the meat eaters among us, or those on the Paleo diet, salmon can specifically help prevent delayed onset muscle soreness, reduce inflammation, and provide you with an abundance of the protein needed for muscle growth. Eat this protein within 45 minutes after working out for maximum effect, either grilled, cooked up in salmon cakes, or raw in the form of sushi or sashimi. All of the above goes for tuna as well, by the way—reasons you might become a pescatarian.

Eggs

If you are an omnivore or ovo-vegetarian, eggs are great way to gain protein first thing in the morning, and an even more effective food to have immediately post-workout to help prevent DOMS. Like cottage cheese, eggs are a rich provider of leucine, and like salmon, eggs contain vitamin D (in their yolks). For your convenience, eggs can be boiled and brought along for immediate consumption after your training. Boil a dozen at the start of each week during your meal prep, and have an easy protein source in the palm of your hand every other day of the week.

Spinach

Did we really get all the way to the end of the list without a vegetable? So sorry! Let’s fix that with spinach. A powerhouse of antioxidants, not only can spinach help prevent diseases like heart disease and various cancers, but it also helps you recover quickly from intense exercise. Spinach’s nitrates help to strengthen your muscles, and its magnesium content helps maintain nerve function. Spinach helps to regulate your blood sugar (in case you worry about the spikes you might get from the sweeter items on this list), and can be added to many dinners, snuck into smoothies, or eaten on its own either raw or sautéed in olive oil.

Resist Damage and Recovery Quickly

These foods help with recovery from DOMS and reduce the amount of soreness you get in the first place by providing your body with the proteins and nutrients it craves when you’re working out to the best of your ability.

A quick note before you go. In your quest for pain-free muscles, you’ll want to avoid:

  • Refined sugar: Just one sugary soda a day can increase your inflammatory markers, as can white bread and other products with refined sugar. Natural sugars don’t bring that kind of adverse effect, so get your sugar from whole foods instead.
  • Alcohol: The dehydration caused by alcohol requires its own special recovery, and will deplete many of your vitamins (especially B vitamins). Some research suggests that alcohol can interfere with how your body breaks down lactic acid, which would increase muscle soreness. If you’re on a mission to build muscle, it’s best to avoid alcohol.

If you’re eating pretty well and avoiding what you shouldn’t eat, but still find muscle soreness a burden after working out, there is always the option to supplement.

What is the best supplement for muscle recovery? Evidence shows that getting all your body’s essential amino acids in balance will help specifically with muscle sprains and pulls, so when supplementing, just make sure you cover the waterfront (rather than choosing one or two essentials and neglecting the rest). Other than that, a diverse diet can be had in choosing natural preventions and remedies for healthy muscle recovery.

How Amino Acids Support Female Muscle Growth

Is it truly more challenging for women to build muscle? To answer that question, we first separate the myths about gender differences and muscle growth from the actual science. Then, we offer tips everyone can use to get serious muscle growth results.

Female muscle growth. It’s not a phrase you hear too often. However, whether you’re a man or a woman, muscle building benefits your overall health and well-being. Strong scientific evidence shows that increasing your lean muscle mass can help you stay healthy as you age, support fat loss by keeping your metabolism running at full capacity and prevent the development of chronic diseases.

If you’re born male, you’re coached from a young age to want to grow up to be big and strong. But if you’re born female, you receive the opposite message. With the emergence of ripped and toned female fitness influencers taking social media by storm, the tides appear to be shifting. Nonetheless, society still tends to instruct girls to train themselves to be as dainty as possible—in part, so they can grow up to be women who attract big, strong men.

But the health benefits of muscle mass apply to everyone, regardless of gender. However, it can be more challenging for women to build muscle for a variety of reasons.

In this article, we’ll explore the scientific realities behind the common belief that muscle building comes more naturally to men than to women. Plus, we’ll offer tips that everyone can use to increase their physical strength and get serious muscle growth results.

Do Men Build Muscle More Easily Than Women?

If you’re at all familiar with the resources out there for people interested in muscle building, you’ve probably noticed that the vast majority of it is written by male authors for male audiences. While that has begun to shift somewhat as more women get into powerlifting, bodybuilding, and sports science, these realms are still dominated by men.

In those realms, a concept that many take for granted is that muscle gains come more easily for men than for women. This concept is propped up by claims that men and women have significant physiological differences that give men an advantage when it comes to physical strength and performance.

 

How amino acids can maximize female muscle growth.

What Science Tells Us About the Differences Between Men and Women

Let’s begin by comparing the average metabolic rates—the calories you burn just by going about your day—for men and women. According to a study published in the American Journal of Clinical Nutrition, about 90% of the variations researchers identified in the baseline number of calories participants expended over a 24-hour period came down to differences in fat mass and muscle mass. Your age has a measurable impact too. Researchers found that participants between 50 and 65 years of age had baseline metabolic rates that were 4.6% lower than participants between the ages of 20 and 30.

Fascinatingly, they reported: “No sex difference in any energy expenditure measurement could be found.” However, women do tend to have slower metabolisms than men, but it’s not because they’re women, it’s because on average, women are smaller and have less muscle mass.

So, let’s look into muscle mass differences. Findings published in the Journal of Applied Physiology reveal that women have, on average, about 67% of the muscle mass men do.

Women lag further behind when it comes to the muscle groups of the upper body than those of the lower body. A research team from the departments of Physical Education and Medicine at McMaster University in Hamilton, Canada set out to determine how gender differences influence strength and muscle fiber characteristics. They found that female participants had approximately 52% of the upper body strength and 66% of the lower body strength of men.

These differences appear to have more to do with the likelihood that men will have larger muscles than with innate sex-based differences, though. A study published in Ergonomics sought to measure the extent to which differences in strength between men and women can be explained by muscle size. Researchers found that when they adjusted their findings to take into account overall muscle mass as well as the size of specific muscle groups, 97% of sex-related differences were in strength. The researchers state that their findings suggest muscle size “almost entirely” accounts for the differences we expect to see between a man’s physical strength and a woman’s. In other words, if a man and woman have comparable muscle mass, they should be equally strong.

It appears that the vast majority of the differences we attribute to sex actually have to do with body composition. A woman and man with similar previous experience in terms of physical activity and comparative amounts of muscle and fat will perform similarly on standard measures of strength.

However, there are some differences between the ways men’s bodies and women’s bodies tend to respond to strength-training regimens and individual workout plans.

How Hormones Affect Female Muscle Growth

Hormones tend to be the first factor people point to when talking about physiological differences between women and men. It’s only logical, given that men’s increased muscle mass results from higher testosterone levels. Hormone levels fluctuate from person to person and over time, but on average, women produce far less testosterone than men do—between 15 and 20 times less, according to data sourced from the U.S. National Library of Medicine.

However, the question of testosterone levels isn’t as clear cut as we tend to think. In fact, some men have lower testosterone levels than some women do. After a team of researchers from the U.K. analyzed the hormone levels of elite athletes, they found significant overlap between testosterone levels for male competitors and female competitors. It’s worth noting that the hormone profiles of elite athletes differ from those of average individuals. It’s also highly likely that women with naturally higher levels of testosterone are more likely to excel at the elite level in certain physical disciplines. The main takeaway is that the idea that men have higher testosterone levels and therefore build new muscle more easily doesn’t entirely hold up.

Furthermore, did you know that testosterone is not the only hormone involved in building muscle mass? Estrogen, which as you may know, women typically produce at higher levels than men do, has also been shown to have significant benefits for muscle growth.

Studies done with animal subjects and well-controlled studies with human subjects support the idea that estrogen can help to prevent the breakdown of muscle tissue that often accompanies the aging process. It appears that estrogen has an overall positive impact when it comes to maintaining and increasing your lean muscle mass.

And an article published in Exercise and Sport Sciences Reviews presented experimental findings suggesting that estrogen may have an anabolic effect on muscles, meaning it supports muscle gain. It appears to do this primarily by lowering protein turnover, which slows the rate of catabolism (muscle breakdown), and enhancing the sensitivity of muscle tissue to resistance training.

Estrogen also boosts your metabolism, making it easier to cut your body fat percentage. While that doesn’t directly contribute to muscle growth, it does mean the new muscles you build will be more visible.

Women and Men Build Different Types of Muscles

We all have two general types of skeletal muscle fibers: slow-twitch, or Type 1, and fast-twitch, or Type 2. Type 1 muscles help power you through feats of endurance, like marathons. And the more Type 2 muscles you have, the better you perform on tests of explosive strength, like Olympic weight training.

There’s a clear divide between the average percentages of Type 1 and Type 2 muscle fibers that women and men typically have. According to Greg Nuckols, an experienced fitness writer who holds a BS in Exercise and Sports Science and three all-time world records for powerlifting, women typically have more Type 1 muscle fibers than men do, about 27% to 35% more. Women also tend to have greater capillary density.

Both give women an advantage in many ways. Greater capillary density means an increased ability to circulate blood through your muscle tissue to bring in fresh oxygen and clear out waste products. And having a higher percentage of Type 1 muscle fibers gives you an improved capacity for glucose and fatty acid oxidation, which translates to a decreased risk of chronic conditions linked to metabolic health, like diabetes and heart disease.

However, Type 2 muscle fibers are thicker, quicker to contract, and engage when your body nears maximum exertion. If you’re looking to increase your muscle mass and build strength so you can lift heavier and heavier weights, you need to recruit your Type 2 muscles. There’s no evidence that Type 1 muscle fibers can be transformed into Type 2 muscle fibers (or vice versa), which means there may always be a gap between the level of explosive strength an experienced female weight lifter can generate and the amount a male lifter at the same level can generate.

Maximizing Muscle Growth as a Woman

While men may have some innate advantages when it comes to building muscle mass, studies show that both men and women gain muscle at the same rate when they commit to workout routines like resistance training, weight training, and high-intensity interval training (HIIT).

Researchers from the University of Maryland Exercise Science and Wellness Research Laboratories conducted a study in which participants committed to a 6-month, whole-body strength-training program that worked for all the major muscle groups in both the upper and lower bodies.

They used MRI images to assess thigh and quadriceps muscle volume as well as mid-thigh muscle cross-sectional area before and after the strength-training program. Their findings showed that the thigh and quadriceps muscle volume increased significantly for all age and gender groups as a result of the strength-training program. The researchers found no significant differences related to either participant age or gender.

In some cases, women can make more significant strength and muscle gains than men. A study published in the International Journal of Sports Medicine examined how men and women responded to weight-training and resistance-training approaches. The researchers found that after following the same short-term training program, female participants made more significant strength increases than male participants did.

For women interested in optimizing their body composition by decreasing their body fat percentages and increasing their muscle mass, there are certain strategies you can put in place to maximize your muscle-building potential.

Train Strategically

When it comes to building muscle, the first step is to institute a strength-training regimen. For those seeking to rapidly increase muscle growth who are comfortable and able to perform high-intensity workouts, the most effective strength-training approach will involve lifting increasingly heavy weights. That might mean using barbell, kettlebells, dumbbells, or other types of weights.

Incorporating weightlifting into your training sessions encourages muscle growth because of the strain it places on your muscles. This wear and tear breaks down the muscle tissues. Then, during the recovery process that takes place while you sleep and on rest days, your muscles rebuild themselves. Each time this process takes place, your muscles grow bigger and stronger.

Adding high-intensity interval training to your exercise routine can also increase your muscle gains. This method of training involves short burst of intense exertion—a great tactic for recruiting your Type 2 muscles.

Increase Your Protein Intake

As you know, your muscles are made up of proteins. In order for your muscles to successfully rebuild themselves after workouts, you need to provide them with an adequate supply of dietary protein.

There’s no one-size-fits-all answer to the question of how much protein your muscles need to properly build and repair themselves. Factors like age, weight, activity level, and training goals will all influence the amount of protein an individual needs to consume.

Federal guidelines set the minimum recommended amount of protein consumption for adults at 17% to 21% of your daily calories, and that’s without taking weight training into consideration.

As Jim White, RD, ACSM, explained, resistance training increases the process of protein turnover. By eating proteins laden with all the essential amino acids, you’re providing your body with the raw materials it needs to build muscle.

According to the American College of Sports Medicine, if you’re looking to build muscle mass, you should aim to consume between 0.5 and 0.8 grams of protein per pound of body weight. That means a 150-pound woman, for example, should set a protein intake target of 75-120 grams of protein each day. It’s also important to consider the percentage of your overall calorie intake that comes from protein.

White, as well as other experts, recommends prioritizing the post-workout window for protein consumption as this has the biggest impact on muscle growth. Findings published in the Journal of the International Society of Sports Nutrition indicate that protein consumption before workouts can also be a key factor. Eating protein both before and after workouts can boost your performance, speed your recovery time, and increase your lean muscle mass.

Amino Acids Can Boost Female Muscle Growth

While it’s entirely possible to meet your body’s protein needs through diet alone, it can be helpful to add in high-quality supplements, including protein powders. Especially if you have a busy schedule that makes it challenging to consume enough protein during meal or snack times, it can be highly beneficial to provide your body with amino acids from other sources.

Researchers have found that certain supplements can be particularly helpful when it comes to building and maintaining muscle mass. If you’re wondering about the best amino acids for muscle growth, here are three to consider.

How amino acids can maximize female muscle growth.

1. Creatine

Creatine, an amino acid compound found naturally in the human body as well as in foods like red meat, has been the subject of hundreds of studies. If you’re lifting weights and looking to amplify your results, you may want to consider supplementing with creatine.

Media reports may have lead you to believe that creatine supplementation can adversely impact the health of your kidneys, but scientists have repeatedly and conclusively found that not to be the case.

After going over all available data on the short-, medium-, and long-term effects of creatine supplementation, researchers from the Higher Institute of Physical Education and Readaptation in Brussels, Belgium found no evidence that creatine causes liver dysfunction in healthy individuals (individuals with pre-existing kidney disease should avoid creatine). The researchers concluded that individuals who take creatine “do not report any adverse effects, but body mass increases.” They also noted that creatine may benefit the health of your heart and help reduce your risk of neurological diseases.

Studies show that supplementing with creatine can increase your lean body mass, enhance your anaerobic working capacity, and minimize the muscle damage caused by extreme exertion.

2. Beta-Alanine

This naturally occurring amino acid has also been the subject of extensive research.

One reason for this is that beta-alanine is the rate-limiting precursor of carnosine, an amino acid found in high concentrations in human skeletal muscle. One study on the effects of beta-alanine supplementation found that it can increase concentrations of carnosine in your muscles, which in turn helps to prevent muscular fatigue.

A separate study published in the Journal of the International Society of Sports Nutrition found pairing beta-alanine supplementation with high-intensity interval training (HIIT) can substantially increase both endurance and aerobic metabolism. It also showed a clear and impressive impact on subjects’ lean muscle mass.

Plus, a third study that examined how beta-alanine impacted anaerobic power output by using tests of physical strength such as timed sprints and a 90° bent-arm hang found that supplementing with beta-alanine improved participants’ results across all categories. Participants who supplemented with beta-alanine were able to achieve simultaneous weight loss and lean body mass increases.

3. Citrulline

Supplementing with citrulline can significantly increase your blood levels of not only this important amino acid, but two other crucial amino acids as well: ornithine and arginine. This can have a wide range of health benefits.

According to findings published in the The Journal of Strength & Conditioning Research, even a single dose of citrulline can improve your physical performance as measured by a flat barbell bench press. It can also reduce post-exercise muscle soreness. Participants were able to complete approximately 53% more repetitions and reported 40% less muscle soreness at both 24 and 48 hours afterward.

A separate study published in the British Journal of Sports Medicine showed that citrulline reduced muscular fatigue and improved muscle metabolism as measured by oxidative ATP production and the rate of phosphocreatine recovery after exercise.

All in all, it appears that this amino acid can improve endurance and speed up recovery time.

Greater Than the Sum of the Parts

Your muscles aren’t composed of single amino acids, but rather 20 separate amino acids. Building muscle mass requires a steady supply of all those amino acids. Nine of those are essential amino acids, meaning you must get them from the foods you eat or supplements you take.

While certain amino acids have been shown to have more dramatic results when it comes to muscle growth, your rate of muscle protein synthesis will be limited by whichever essential amino acid is in the shortest supply. That’s why some of the foremost experts on amino acids believe that taking an essential amino acid (EAA) blend is ultimately the most effective way to build your muscle mass. Using a supplement formulated to include all the required amino acid building blocks stimulates the production of new muscle tissue more effectively than any single amino acid could.

Best Amino Acids for Muscle Growth

The best amino acids for muscle growth tip the balance in favor of muscle protein synthesis. And making a complete protein requires adequate availability of each of the amino acids. Read on to find out the formulation of amino acids that is best for building muscle.

Before we get into the best amino acids for muscle growth, let’s first review the makeup of muscle. Muscle tissue is composed of a variety of proteins that are in a constant state of turnover—proteins that are no longer functioning well are being broken down and new ones are being produced. Muscle growth occurs when the rate of synthesis of new muscle protein exceeds the rate of breakdown.

Muscle protein is composed of 20 different amino acids hooked together in a specific order. Nine of the amino acids are essential amino acids (EAAs) and cannot be produced in the body. The other 11 are nonessential (NEAAs) and can be produced in adequate amounts within the body.

Muscle protein synthesis (the building of new muscle protein) involves a series of molecular events that result in the component amino acids being linked together in a specific order. For this reason, amino acids are often called the building blocks of protein. Making a complete protein, therefore, requires adequate availability of each of the amino acids. In that sense, there is no individual best amino acids for muscle growth, because they are all required to produce muscle protein. Rather, there are formulations of amino acids that are “best” for specific circumstances, such as building muscle.

Where Do Amino Acids Come from for Muscle Protein Synthesis?

When protein is broken down during muscle protein turnover, amino acids are released into muscle cells. Most of these amino acids become the precursors for the synthesis of new muscle protein. However, some of the amino acids from protein breakdown are released into the blood and delivered to other tissues and organs, and still other amino acids from protein breakdown are irreversibly oxidized/damaged. Therefore, the rate of reincorporation of amino acids from protein breakdown into newly synthesized muscle protein will always be less than the rate of protein breakdown. Without other sources of amino acids, a reduction of muscle protein and subsequent muscle loss occurs.

There are two ways to get the additional amino acids you need for muscle protein synthesis.

  1. They are produced in the body. (NEAAs can be produced in the body, so only a minimal amount must be consumed in the diet to meet all demands.)
  2. EAAs, on the other hand, cannot be produced in the body and must be consumed in the diet.

Research shows that consuming EAAs stimulates muscle protein synthesis and helps build muscle, but eating more NEAAs doesn’t add any further stimulus. When EAAs are consumed, the additional NEAAs required for the production of complete proteins are produced in the body. Ingesting EAAs, either as dietary protein or as amino acid supplements, shifts the balance between synthesis and breakdown of muscle protein to favor the net production of new muscle protein, which defines muscle gain.

What Are the Best Amino Acids for Muscle Growth?

Muscle protein is composed of a specific amount of each amino acid, hooked together in a specific order. In that sense, all the amino acids are equally important, as a shortage of any of them will stop the process of synthesis.

The EAA in shortest supply is called the limiting EAA. The availability of the limiting EAA will limit the rate of muscle protein synthesis, regardless of the availability of all the other EAAs and NEAAs. Therefore, you could say that the limiting amino acid in any formulation of EAAs is the most important.

This is the major problem with supplements that only have the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine. Since the other essential amino acids are not provided, the rate of muscle protein synthesis is not improved. Because of this, BCAA supplements have been proven to provide a far smaller effect on muscle growth than a complete EAA formulation.

It is possible to gain insight into the amount of each EAA that is needed to avoid that EAA being the limiting EAA by looking at the requirements for the individual EAAs. By definition, NEAAs are not required in the diet, so when we talk about dietary requirements we are talking only about EAA requirements. The dietary requirement for each EAA differs. Here are the daily requirements for EAAs for adults as published by the Food and Agriculture Organization of the World Health Organization (FAO/WHO).

Best Amino Acids for muscle growth

The requirements are based on a number of factors, including the composition of total body protein. From the requirements shown above, it is clear that all EAAs are not “equal.” The requirements for leucine and lysine are the highest, while the requirement for tryptophan is quite low.

It could be argued that the best amino acids for muscle building parallel the individual requirements of the EAAs. Indeed, that is the basis for the official FAO/WHO grading of protein quality, called the Digestible Indispensable Amino Acid Score (DIAAS). Indeed, an EAA supplement that closely parallels this distribution will be an effective stimulant of muscle protein synthesis in any circumstance. The bottom line is that you need all the essential amino acids to have any effect on muscle mass, and any nonessential amino acid need not be included in a dietary supplement.

Leucine for Muscle Growth

There has been considerable research over the past 15 years that indicates that alternative mixtures of EAAs may be more beneficial in particular circumstances. Most of the research has centered on the EAA leucine. In addition to being the most abundant EAA in body protein, under certain circumstances, leucine can function to regulate molecular processes within the muscle cell. In those circumstances, it can be called a “nutraceutical.”

Leucine can activate the molecule called mTOR, which gets muscle protein synthesis started. Various conditions associated with progressive muscle breakdown and loss of muscle strength, such as cancer, heart failure, and aging, can suppress the activity of mTOR and associated molecules. When mTOR activity is limited, it may be preferable to increase the proportion of leucine to as high as 35% to activate mTOR. At the same time, activation of mTOR and associated molecules in the muscle cell is not sufficient to increase muscle protein synthesis. You also need an abundance of all EAAs to produce complete proteins. Therefore it is necessary to limit the proportion of leucine in an effective dietary supplement to below 40% so that sufficient amounts of the other EAAs can be included.

If extra leucine is added to a dietary supplement such as whey protein powder to capitalize on its action as a nutraceutical, then the remainder of the supplement should provide the other EAAs in proportion to their contribution to the composition of muscle protein. It seems logical that this would be dictated entirely by the composition of muscle protein, but it is not quite so straightforward.

The absorbed ratios of the different EAAs will not be directly reflected in the EAAs inside the muscle cells because some amino acids are transported into the cell faster than others. Lysine, in particular, is transported sluggishly into the muscle. When lysine is consumed, less lysine will enter the muscle cell than would be expected from the profile of the consumed EAAs. Consequently, to increase the lysine concentration inside the muscle cell in proportion to the lysine content of muscle protein it is necessary that lysine comprise 20% or more of the total EAAs consumed to achieve the maximal muscle-building effect.

Different Strokes for Different Folks

The most effective EAA supplement for muscle growth will have all the EAAs and roughly parallel the requirements cited above. However, alternative formulations may be “best” in different situations. For example, while a high proportion of leucine may be best for older individuals with heart failure, a disproportionate amount of leucine may not be needed by a young athlete after a resistance workout. This is because the resistance workout will activate mTOR and associated molecules, and if the proportion of leucine is in line with the composition of muscle protein (around 23%), then relatively more of all the other EAAs needed to produce complete protein can be included in the supplement.

Even the optimal formulation for exercise might vary, depending on when the supplement is consumed and the type of exercise. For example, endurance training causes a selective increase in leucine oxidation, in which case a supplement high in leucine would be optimal as a post-workout supplement following exercise to speed up muscle recovery.

If the EAA supplement is meant to be consumed as a pre-workout supplement for exercise performance, it may be formulated to optimize the concentrations of neurotransmitter precursor availability in addition to providing EAAs for muscle protein synthesis.

Regardless of the specific circumstance it is meant for, the “best” formulation will include all the EAAs and not just the BCAAs or specific amino acids like beta-alanine or arginine. A complete formulation will more effectively stimulate the production of new muscle protein than any individual or sub-group of EAAs possibly can.

How to Use Amino Acids for Bodybuilding

Amino acids have become some of the most popular types of bodybuilding supplements across multiple disciplines. Both BCAAs and EAAs can be used on their own or in the form of “stacks”—specialized blends of multiple supplements that work together synergistically to provide even greater benefits than when taken on their own.

Bodybuilding usually refers to increasing and sculpting muscle mass for appearance as well as strength. In a more general sense, bodybuilding can refer to increasing muscle mass and function for the purpose of competing in sports such as football or power sports (e.qg., shot putting, discus throwing, etc.). It is a given that bodybuilding requires resistance training. If bodybuilding is for the purpose of improving competitive performance in a specific sport there are likely to be training requirements unique to that sport. This discussion on amino acids for bodybuilding will, therefore, not focus on the specific aspects of training. Regardless of the goal of training, amino acids play a key role in bodybuilding.

The Impact of Nutrition on Bodybuilding

Training tends to be the first factor most consider when seeking to build lean muscle, however, the nutrients we provide our bodies with can be equally influential—or more so—in determining how quickly we progress toward our goals. No matter how intensely you train, you will not be able to achieve the results you desire if you’re lacking certain crucial nutritional elements.

Obtaining all the nutrients you need from your diet alone in the quantities necessary for maximal bodybuilding results can be challenging. That’s where workout supplements come in.

By taking targeted sports nutrition supplements, you can ensure you get all the nutrients you need to build muscle, speed recovery time, decrease muscle soreness, amp up energy levels, and more.

Bodybuilding Supplements Then and Now

Depending on how broadly you interpret the idea of dietary supplementation, the idea of bodybuilding supplements can be traced back to ancient Greece.

According to Professor Andrew Dalby and other experts, Greek and Roman athletes consumed large quantities of meat and wine as well as herbal concoctions and tonics with the goal of increasing their strength and stamina.

In the early 1900s, Eugen Sandow, a pioneering German bodybuilder whose legacy earned him the honorific “father of modern bodybuilding,” advised all who wished to maximize their muscle growth to adhere to the dietary rules he himself followed. Bodybuilder Earle Liederman, who rose to prominence in the 1920s, recommended drinking what he called “beef juice” or “beef extract” (a substance the luminaries of today’s wellness landscape call “bone broth” and chefs simply refer to as “consommé) in order to speed muscle recovery.

In the 1950s, protein powders entered the picture as recreational and competitive bodybuilding became ever more popular with ever-broader audiences in the United States and elsewhere. Irvin P. Johnson, who operated a bodybuilding gym in Chicago, was one of the first to market egg-based protein powder. According to an article he published in Iron Man with the title “Build Bigger Biceps Faster with Food Supplements,” his specialized line of protein powders fueled serious strength gains. According to the article, he went from only being able to leg press 165 pounds for 10 repetitions to 660 pounds for 12 repetitions!

The bodybuilding supplement industry grew at an exponential rate throughout the 1970s and 1980s, fueled both by increased interest in recreational bodybuilding as well as advancements in advertising. Then, in October of 1994, Congress passed the Dietary Supplement Health and Education Act, a piece of legislation that transferred responsibility for determining the safety of dietary supplements such as protein powders and other mainstays of sports nutrition from the government to the manufacturers of the products. Unless they added a new dietary ingredient, manufacturers were no longer required to provide the U.S. Food and Drug Administration (FDA) with evidence to substantiate the safety or efficacy of their products. Legal experts believe this opened the door for the supplement industry to sell even more of their products. According to a Consumer Reports publication, annual sales of sports nutrition supplements hit $2.7 billion in 2010. And according to the “Sports Nutrition and High Energy Supplements – Global Market Outlook (2017-2026)” report sports nutrition and high energy supplements made $44.58 billion in 2017 with an outlook of $124.85 billion by 2026.

Defining the Term “Bodybuilding Supplements”

Just as the term bodybuilding can encompass both physique-focused and performance-focused endeavors, so too can the term “bodybuilding supplements” encompass a multitude of dietary supplements utilized by individuals engaged in bodybuilding as well as weight lifting, mixed martial arts, and other athletic pursuits to increase lean body mass as well as bring about other desirable outcomes such as:

  • Decreased body fat
  • Sharper muscle definition
  • Enhanced athletic performance

Amino acids have become some of the most popular types of bodybuilding supplements across multiple disciplines. Both branched-chain amino acid supplements (BCAA supplements) and essential amino acids (EAAs) can be used on their own or in the form of “stacks”—specialized blends of multiple supplements that work together synergistically to provide even greater benefits than when taken on their own.

Making the Most of the Building Blocks of Protein

Amino acids have earned the nickname “the building blocks protein” because of the vital role they play in creating muscle tissue. While it’s certainly possible to obtain all the amino acids you need simply by eating high-protein foods like eggs, lean meats, legumes, vegetables, and pseudo-grains like quinoa, amino acid supplements can be a convenient and efficient way to maximize the benefits of amino acids.

One of the most compelling reasons to use supplements can be captured in a single word: bioavailability. Bioavailability refers to how efficiently a substance can be metabolized and the percentage of what’s ingested that’s utilized for its intended purpose inside the body.

Several factors determine the bioavailability of each amino acid. For example, when taking in amino acids from a food source, the amount of fat contained in that food influences the length of time it takes for amino acids to be put to use. The way you cook food can also impact the amino acids it contains. Some heat-sensitive amino acids can even decompose when cooked. And not all amino acid supplements are metabolized at the same rate. The physical nature of the supplement will have the most significant influence on its bioavailability. A BCAA powder, for instance, will be digested differently than a supplement in pill or liquid form. The extent to which a supplement is pre-digested as well as whether it contains any fillers or binders impact its overall bioavailability.

Understanding Muscle Protein Turnover

Muscle protein turnover is the metabolic basis that powers increased muscle mass, strength, and function.

Muscle protein turnover refers to the constant breakdown of older muscle proteins that are no longer operating at peak efficiency and their replacement with newly synthesized, more efficient muscle protein fibers. The balance between protein synthesis and breakdown determines whether a muscle is growing or shrinking.

Muscle function is accomplished by the contraction of muscle protein fibers. Muscle strength and function are determined by how many muscle protein fibers you have and the efficiency with which they contract. Increasing muscle protein mass and contractile efficiency is accomplished by optimizing muscle protein turnover.

For bodybuilding, the goal is to make the rate of muscle protein synthesis exceed the rate of protein breakdown. Further, the increased balance between muscle protein synthesis and breakdown should optimally be accomplished mainly by stimulating synthesis, not lessening breakdown—protein breakdown gets rid of muscle proteins that are not functioning efficiently, so it is good to keep that process functioning at full speed.

The Mechanics of Muscle Protein Synthesis

Muscle proteins are composed of a series of amino acids hooked together in a specific order determined by the messenger RNA (mRNA) in the cell for each specific muscle protein. The sequence of the mRNA is dictated by the DNA in the cell. There is a specific molecule for each amino acid (tRNA) that delivers it to the mRNA as required for incorporation into the protein that is being produced.

A simple, conceptual way to think about the process of muscle protein synthesis is to compare it to the construction of a building. The DNA is basically the idea for the design of the building. The RNA is the written plan or blueprint, and transcription of the mRNA from the DNA is the process of writing up the plan. The tRNA molecules that bring the amino acids to the mRNA for incorporation into protein are like trucks that bring bricks to the building site, and the hooking of amino acids together in the proper order on the mRNA corresponds to the builder putting the bricks together according to the blueprint. The protein is the final product, or completed building, ready to serve its function.

The details of how muscle protein is made are important only so that it is clear why all the amino acids must be available in abundance. If the mRNA dictates that the next amino acid in the chain making up the protein is a particular amino acid that is deficient, then the process is halted and no muscle protein is produced.

How Amino Acids Impact Muscle Protein Synthesis

We must derive certain amino acids, as I touched on earlier, from dietary protein. However, the human body can synthesize other amino acids through chemical reactions that occur in the liver and select sites throughout the body.

The amino acids that must be obtained from the diet are called essential amino acids, or EAAs, while the amino acids that can be made in the body are called nonessential amino acids, or NEAAS.

The nine essential amino acids are leucine, isoleucine, valine, phenylalanine, lysine, methionine, phenylalanine, threonine, and tryptophan. Three of the EAAs, leucine, isoleucine, and valine, have been subcategorized as branched-chain amino acids (BCAAs), a descriptor which refers to their chemical structure. We typically put the number of nonessential amino acids at 11, as that’s how many NEAAs can be found in human protein, though other NEAAs like citrulline and ornithine can be found elsewhere in the body.

Since your body can produce NEAAS and they are available in abundance, the availability of EAAs serves as the limiting factor for setting the rate of muscle protein synthesis.

Using Essential Amino Acids to Stimulate Muscle Growth

Consuming essential amino acids, either as dietary protein or supplements, is the most potent stimulus of muscle protein synthesis. Consuming nonessential amino acids, either alone or with EAAs, has no impact.

EAA supplements have been shown to trigger muscle protein synthesis and increase muscle mass, strength, and physical function in at least 25 clinical trials. The muscle-building response to EAAs is 2 to 4 times greater than the muscle-building response to the same amount of a whey protein supplement. The muscle-building response to EAAs is even greater than the response to hormonal treatment with testosterone, growth hormone, or insulin.

There is one very big must when it comes to EAA supplementation, however. In order to be effective, all the EAAs are required. That being said, there are varying degrees of importance among the EAAs.

Leucine, which is both an EAA and a BCAA, is particularly important. Leucine is the most abundant EAA in muscle protein, so it should comprise the highest proportion of an EAA supplement. Beyond its role as a component of muscle protein, leucine can signal the molecular mechanisms within the cell to initiate the process of protein synthesis. Important as leucine may be, however, it cannot function alone. All the other EAAs are required as well, roughly in proportion to their relative content in muscle. It is not possible to make muscle protein from leucine alone.

The Role of Essential Amino Acids for Bodybuilding

It is clear from the above discussion that making sure you consume enough essential amino acids is an important part of bodybuilding. Even when using EAA supplements, the main source for your essential amino acids intake will likely be dietary protein. Therefore, the place to start is with your diet.

Protein is the key dietary component of the basic bodybuilding diet. It will increase your muscle mass. You should set a goal of eating approximately 30% of your caloric intake as high-quality protein.

When I say high-quality protein, I mean a protein that contains a high abundance of essential amino acids. High-quality proteins are generally animal-based proteins. These protein food sources also have a significant amount of non-protein calories. Therefore, eating a sufficient amount of high-quality protein to supply all the EAAs you need is difficult through normal diet alone.

You will most likely run into issues with the flexibility of your diet when eating this amount of high-quality protein food sources because of the non-protein calories. Therefore, EAA supplements can play a vital role in helping you meet your dietary goal for EAA intake.

While the focus of your basic diet should be high-quality protein, you must remember that energy substrates (carbohydrates and fat) are important too. As an example, in a tightly controlled study, subjects drank the same amount of protein in the form of milk. In one case, it was skim milk, and in the other case whole milk. The stimulation of muscle protein synthesis was greater with the whole milk. Under these study conditions, the additional calories provided by the fat in the whole milk helped to fuel muscle building.

You must be in a positive energy balance to gain a significant amount of muscle mass. Carbohydrate is of less importance for resistance training than it is for endurance training, but you should eat enough fruit and vegetables to meet the RDAs for micronutrients. Also, carbohydrate intake will stimulate insulin release, and insulin is an anabolic hormone that will increase the amount of muscle protein made from your EAA intake.

Fat intake will also amplify the anabolic effect of EAAs, and therefore you can eat animal-based, high-quality protein foods without worrying about eating too much fat.

What you do want to keep in mind with your bodybuilding diet is that the more you eat, the bigger you will get. If you do eat a lot while lifting heavy weights and consuming EAA supplements as recommended, a significant part of the weight gain will be muscle.

You will also gain fat with this dietary approach, so you need to carefully monitor your body composition to be sure that the extra fat you put on does not counteract the benefits of the muscle gain. In a sport like powerlifting, that is not likely to be the case, but if you are bodybuilding for appearance, you must reach a balance between muscle and fat gains. This can be accomplished by incorporating aerobic exercise into your training program.

How to Use Essential Amino Acids for Optimal Bodybuilding Results

amino acids for bodybuilding

The research documenting the optimal use of amino acids for bodybuilding is extensive. Experts can provide precise guidance on the effects of taking EAAs both pre-workout and post-workout.

Consuming 15 grams of EAAs 30 minutes before starting your workout will elevate blood concentrations of essential amino acids throughout your workout and stop the muscle breakdown that would otherwise occur. A 15-gram dose of EAAs achieves a greater response on muscle protein synthesis than either casein or whey protein can, without creating the fullness that can hinder a workout.

Then immediately after your workout, take another 15 grams of EAAs. One hour later, take another 15-gram dose.

These recommendations stem from the assumption that you will be working out every day. When you do take off days, you should still consume the same amount of EAAs. Instead of using your workouts to determine the timing, however, take your EAAs between meals.

Between the completion of dinner and breakfast the next morning, you may go for 12 hours or more without food. During this post-absorptive time, muscle tissue breakdown transpires in order to supply amino acids to tissues and organs that have no protein reserve. Therefore, to fuel maximal muscle-building response around the clock, you should consume another 15 grams of EAAs before bedtime. If you have wholly committed to maximizing muscle gain, you can even set your alarm for a final dose at about 4 am.

Alternatively, you can take 20 grams of casein protein at bedtime. Because casein coagulates in the stomach, your body digests it at a slower rate, meaning the amino acids it contains are then absorbed over many hours. While the anabolic effect will be less than if you take the EAAs, this approach will save you the trouble of getting up in the middle of the night.

The total amount of supplemental EAAs you ingest should be in the range of 60 grams per day. Consuming this amount of EAAs will stimulate the production of new muscle protein without you having to also take in a significant amount of non-protein calories. The result will be a lean body with increased muscle mass and minimal increase in fat mass. Sixty grams of EAAs in addition to what you eat as part of your bodybuilding diet is needed to drive protein synthesis past what may be your normal genetic limit.

Do EAA Supplements Have Side Effects?

This a reasonable question, because bodybuilding requires a much higher than average EAA intake. An important caveat to state up front is that I am focusing exclusively on side effects from EAA supplements.

When your EAAs come from an unusually high amount of dietary protein intake, that will increase the rate of amino acid oxidation and as a result, burden the kidneys to excrete the ammonia and urea that are natural byproducts of NEAA oxidation.

The great thing about EAA supplements, however, is that there is no such increased oxidation of NEAAs when EAAs are consumed. This is because NEAAs are not also being consumed but are rather being produced in the body. In fact, the oxidation of the NEAAs actually goes down, since they are being incorporated into protein at an increased rate.

Consequently, there is no reason to worry about the side effects of EAA supplements. The FDA has determined EAA supplements to be Generally Regarded as Safe (GRAS), while the Food and Nutrition Board of the National Academy of Science has determined that there is no upper limit of consumption beyond which would not be safe.

Amino Acid Infusion: Is There an Advantage Over Oral Ingestion of Amino Acids?

Amino acids can be delivered either by intravenous infusion or oral ingestion. Both routes support protein metabolism in the body, as well as provide amino acids for other purposes. But what are the advantages and disadvantages of each?

The use of amino acid infusions to provide nutritional support to individuals incapable of eating a sufficient amount of dietary protein to meet nutritional requirements dates back to the 1960s. An amino acid infusion can either provide partial nutritional support or may be given as part of total parenteral nutrition (TPN). TPN provides all nutrition, including amino acids, carbohydrate, fat, and vitamin and minerals via intravenous infusion, or amino acid injections. But is there a significant advantage to taking amino acids intravenously over taking amino acids orally as a supplement?

Intravenous Amino Acids and TPN

Intravenous amino acids can provide nutritional therapy for protein metabolism (the breaking down and building up of proteins).

An amino acid infusion contains the amino acids with the greatest protein-stimulating effect. These include the essential amino acids leucine, isoleucine, lysine, valine, phenylalanine, histidine, threonine, methionine, and tryptophan, as well as the nonessential amino acids alanine, arginine, glycine, proline, serine, and tyrosine. These amino acids act as protein-building blocks, encouraging protein synthesis in muscle cells and preventing protein breakdown.

An amino acid injection is the administration of amino acids and other nutrients by way of parenteral nutrition. Parenteral administration utilizes routes outside the gastrointestinal (GI tract), such as intravenous routes. Enteral nutrition, on the other hand, is food or drug administered by way of the GI tract, such as with tube feeding.

Intravenous infusion of amino acids is used for patients who cannot take in food or nutrients through the enteral route (GI Tract). For instance, if gastrointestinal absorption is disrupted by inflammatory disease or obstruction, or if tube feeding is not providing adequate nutritional support.

Aminosyn® II is a popular amino acid injection given by way of peripheral vein or central vein infusion and used as a source of nitrogen in the short-term nutritional therapy of patients with adequate body fat who are unable to sustain oral nutrition. This type of amino acid infusion is also administered to help prevent or reverse negative nitrogen balance in patients who cannot take in nutrients via the enteral route.

Individuals who have had large portions of their intestines removed surgically can live indefinitely on total parenteral nutrition (TPN). A 15% amino acid injection can be administered by use of a central venous catheter or by peripheral vein. This amino acid infusion is coupled with vitamins, trace elements, electrolytes, and energy nutrients to provide the necessary nutritional support for weight maintenance or weight gain. In order for the amino acids from TPN to be adequately absorbed and utilized, energy requirements must be met. Energy is typically provided as a combination of dextrose to support carbohydrate metabolism and an intravenous fat emulsion that offers up essential fatty acids to protect against essential fatty acid deficiency and fulfill the dietary balance of fat and carbs.

TPN using amino acid injections can promote muscle protein synthesis, as well as meet other requirements for amino acids, including immune function and brain neurotransmitter synthesis.

The primary drawback to amino acid infusion as the sole source of amino acids from the physiological perspective is that the intestine atrophies. This is because some of the amino acid requirements of the gut are satisfied by direct uptake of amino acids from the digestion of orally ingested protein or amino acids. Atrophy makes the intestines more permeable to diffusion of bacteria and bacterial products from the gut into the body. Of course, if TPN is used because of the removal of the gut, this point is moot. If the intravenous infusion of amino acids is used alongside orally ingested protein, gut integrity will be maintained so long as the oral intake is sufficient.

Benefits of Amino Acid Infusion

The clinical benefits of amino acid infusion in patients who are incapable of ingesting adequate nutrition orally are well established. In addition, intravenous infusion of amino acids in individuals fully capable of ingesting amino acids orally is gaining popularity. The “selling point” of this therapy is that the exact concentrations of individual amino acids in the blood can be precisely controlled. This is promoted as particularly important to the relative concentrations of amino acid precursors of specific brain neurotransmitters. This approach is used in recovery from addiction, as well as for general support of protein metabolism in the body.

The premise of intravenous amino acid therapy is that the individual cannot get the full benefit from orally ingested amino acids, or that the intravenous infusion somehow confers special beneficial effects.

Advantages of Oral Ingestion of Amino Acids

The oral ingestion of amino acid solutions has advantages over amino acid infusion. There is no risk associated with oral ingestion, whereas intravenous infusion carries with it the risk of vein irritation. A health care provider is needed to perform the intravenous infusion, whereas free amino acids for oral consumption are relatively cheap and readily available.

It is possible to obtain a mixture of essential amino acids for oral consumption specifically designed for a particular condition, such as reaching your ideal body weight, whereas the options for intravenous infusion are much more limited due to the arduous procedure to obtain approval from the FDA.

There are also physiological advantages to the oral ingestion of amino acids over peripheral infusions. Most important of these is that the uptake and utilization of amino acid solutions by the intestines provides a direct source of essential nutrition.

Orally ingested amino acids are directly absorbed by the intestines and require no digestion. The amount of amino acids provided to the body by the two routes (oral and intravenous) are thus similar. Since orally ingested amino acids pass through the intestines, liver, and other organs before reaching the peripheral circulation, the peripheral plasma concentrations of amino acids reach higher levels when infused intravenously. Conversely, orally ingested amino acids provide more direct support of the internal organs.

Orally ingested and intravenously infused amino acids both stimulate muscle protein synthesis, which is the metabolic basis for muscle growth and strengthening. A clinical study of older individuals showed that muscle protein synthesis was stimulated in response to both intravenously infused as well as orally ingested amino acids. In addition, the profile of amino acid concentrations in the blood reflected the profile of the orally ingested amino acids, so there is no advantage to intravenous infusion in terms of supplying the proper balance of amino acids needed to synthesize neurotransmitters in the brain. Further, a clinical response was observed at dosage levels that are able to be consumed orally without much difficulty.

Side Effects of Amino Acid Injections

Amino acid infusions are now being marketed as a way to boost athletic endurance, protect against muscle loss, and even improve the health of the central nervous system. While amino acid solutions can indeed impart these benefits, amino acid injections were not originally developed for healthy individuals tackling body weight goals. Oral amino acid supplements, however, can help build muscle, sharpen cognitive function, and enhance athletic endurance, and there are no needles or doctors involved. It’s as easy as mixing an amino acid powder with water.

One of the biggest advantages of taking an oral amino acid supplement over an amino acid injection is that no special care is needed and there are no side effects to contend with.

Amino acid injections can cause the following adverse reactions:

  • Inflammation/redness at the injection site
  • Irritation
  • Nausea
  • Flushing
  • Fever
  • Allergic reactions
  • Weight gain
  • Jaundice
  • Urine changes
  • Weakness

Contraindications for amino acid injections are indicated for individuals in hepatic coma, with hepatic insufficiency, severely impaired kidney function or renal failure, or suffering from metabolic disorders due to compromised nitrogen utilization or hypersensitivity to one or more amino acids.

The Verdict

Amino acids can be delivered either by intravenous infusion or oral ingestion of amino acid solutions. Both routes support protein metabolism in the body, as well as provide amino acids for other purposes.

The intravenous infusion procedure has risks and costs that are avoided by oral ingestion, and the amino acid profiles in available intravenous infusion mixtures are limited. For these reasons, amino acid infusion should be used only in individuals who are incapable of ingesting amino acids or who have a limited capacity for absorption. Oral ingestion is the preferred route of delivery of amino acids in most circumstances.

Leucine Muscle Building and Performance: The Magic Bullet?

Leucine has received special attention for its role in muscle building, not only because it is the most abundant EAA in muscle protein, but also because of its nutraceutical role as a regulator of muscle protein synthesis. Is leucine the “magic bullet” of muscle building?

Leucine is one of the nine essential amino acids (EAAs). EAAs are considered “essential” because the body can’t make them, and they must be consumed as part of the diet. Among the EAAs, leucine has received special attention for its role in muscle building, not only because it’s the most abundant EAA in muscle protein, but also because of its nutraceutical role as a regulator of muscle protein synthesis—the process of muscle building. But are these leucine muscle building benefits the “magic bullet,” or is leucine no more or less important than any of the other EAAs? The truth is that it falls somewhere in between.

What Is Leucine?

Leucine is one of the three branched-chain amino acids (BCAAs), the other two being isoleucine and valine. The term branched-chain refers to the chemical structure of these EAAs, which consists of branched side chains—the shorter chains of atoms attached to the main chain, or backbone, of the molecule.

Leucine is the best known of the BCAAs and is, as already mentioned, the most abundant EAA in muscle tissue. In addition, leucine acts as a signal to activate various cellular functions, including the process of protein synthesis.

How Muscle Protein Synthesis Works

Muscle protein is in a constant state of turnover, being continuously broken down and resynthesized. Muscle building takes place when the rate of muscle protein synthesis exceeds the rate of muscle protein breakdown. This can occur when there’s a stimulated rate of muscle protein synthesis, a suppression of muscle protein breakdown, or a combination of the two.

The process of muscle protein synthesis itself involves the hooking together of a series of amino acids in a very specific sequence and amount. Under normal conditions, most of the amino acids that hook together to form new muscle protein are those released during protein breakdown.

However, about 15% to 20% of the amino acids released during protein breakdown are not available to build new muscle protein. Some are irreversibly oxidized, while others are released into the bloodstream and taken up by other tissues and organs. For this reason, an additional source of amino acids is needed so that the rate of protein synthesis can catch up with, or exceed, the rate of protein breakdown.

Eleven of the amino acids in body protein are nonessential, which means the body produces them on its own to meet the demands of protein synthesis rates. By contrast, EAAs such as leucine must be consumed in the diet since they can’t be produced in the body. For this reason, consuming sufficient EAAs is mandatory for increasing the rate of muscle protein synthesis.

Leucine Muscle Building Supplements

Muscle protein can’t be built with leucine alone. In fact, for new muscle protein to be produced, all of the EAAs must be available in proportion to their respective contributions to the composition of that protein.

Since leucine is the most abundant EAA in muscle protein, comprising about 23% of the total EAAs, high leucine intake is essential for the production of muscle protein. Consequently, the profile of EAAs consumed for the purpose of stimulating muscle protein synthesis—whether in a natural protein food source or an amino acid supplement—must contain a relatively high proportion of leucine.

There’s no debate about the importance of leucine as a building block of muscle protein. Neither is there any controversy regarding the need for leucine to make up at least 20% to 25% of consumed EAAs to maximally stimulate muscle protein synthesis.

The question is, rather, whether the effects of leucine are so unique that this one substance should constitute a disproportionately greater amount of a dietary amino acid supplement compared with the other EAAs. In other words, is leucine supplementation alone beneficial for building muscle?

Keep in mind that this question is relevant only to amino acid supplements, as there is no natural protein source made up of more than 23% leucine, and there is no natural protein source that contains only leucine. So, in order to answer this, we must first understand leucine’s role as a nutraceutical.

Leucine has been called a nutraceutical because it has the ability to stimulate muscle protein synthesis on its own and is more than just one of the components of muscle protein. In fact, leucine can actually initiate the process of protein synthesis by activating a group of intracellular compounds known collectively as initiation factors.

The key initiation factor activated by leucine is a protein called mammalian target of rapamycin (mTOR), which acts as a sensor within the cell. When leucine concentrations are low, mTOR receives the signal that there’s not enough dietary protein present to build new skeletal muscle protein and is deactivated. But when the concentration of leucine within the cell increases, mTOR is activated.

Activation of mTOR can increase the amount of muscle protein produced, provided there are enough of the other EAAs (in addition to leucine) available to make complete proteins.

Muscle Protein Synthesis and mTOR

In normal, healthy adults, mTOR can be activated and muscle protein synthesis stimulated with a balanced EAA supplement, so there’s no need for extra leucine. However, in many clinical states, muscle protein synthesis is just not as responsive when EAAs are consumed, either as food or as supplements.

When this happens, it’s referred to as anabolic resistance—the reduced stimulation of muscle protein synthesis in response to protein intake. Anabolic resistance often occurs alongside conditions such as cancer or severe trauma or illness or during the regular process of aging.

During a state of anabolic resistance, an EAA supplement containing a disproportionately high amount of leucine (35% to 40%) may be needed to activate mTOR and overcome the resistance.

My team and I actually discovered this in 2006, when we studied the beneficial effects of an EAA mixture with leucine on muscle protein metabolism in elderly and young individuals. You can read about the study, published in the American Journal of Physiology, Endocrinology, and Metabolism, here.

But leucine is not the only way to activate mTOR. Resistance exercise can also further elevate mTOR, providing the potential for increased muscle protein synthesis. However, when engaged in resistance training, sufficient EAAs must be available for the further activation of mTOR to translate into increased protein synthesis.

Put simply, you can’t make something out of nothing. And that’s because a shortage of even one EAA will limit the stimulation of muscle protein synthesis, even after a heavy resistance workout. So while mTOR activation isn’t always linked to increased protein synthesis, it is an anabolic signal when all the necessary components are present.

Leucine Alone Isn’t Enough

The best way to envision the role of leucine in protein synthesis is to think of the EAAs as a football team, where leucine is the quarterback and the other positions are filled with other EAAs, each with their own specific role. Just as a team of only quarterbacks wouldn’t have much success in a game, a nutritional supplement wouldn’t have much success if it contained only leucine.

There have been a number of studies examining the effectiveness of leucine as a nutritional supplement. And as predicted by the analogy above, leucine alone has been shown to have little effect on muscle building—according to a 2011 study published in the Journal of Nutrition.

Compare these findings with a study we published in the journal Clinical Nutrition that showed how a formulation of EAAs with a high proportion of leucine (35% to 40%) helped overcome anabolic resistance and improve muscle mass, strength, and physical function in the elderly.

Leucine is important, but it can’t do the job alone!

Leucine and Muscle Protein Breakdown

The role of leucine in stimulating muscle protein synthesis has been studied extensively, but the building of muscle is determined not only by the rate of protein synthesis but also by the balance between the rates of synthesis and breakdown.

With this in mind, it’s interesting to note that leucine also has the ability to reduce the rate of muscle protein breakdown and, thus, muscle loss. One reason for this is that leucine can stimulate the release of the hormone insulin, and the suppression of muscle protein breakdown by insulin is well known.

As one of the BCAAs, leucine can also suppress protein breakdown directly. However, suppressing muscle protein breakdown only helps build new muscle if the rate of muscle protein synthesis is greater than the rate of breakdown, and this may not occur when consuming just leucine or BCAAs.

In fact, a reduction in muscle protein breakdown caused by leucine or BCAAs alone is accompanied by a corresponding reduction in the rate of muscle protein synthesis. This reflects the fact that the major source of EAAs for building new muscle protein is the EAAs that are released by protein breakdown. Therefore, if muscle protein breakdown is suppressed, the availability of EAAs for protein synthesis is also reduced.

As in the case of muscle protein synthesis, leucine can play a potentially important role in building muscle by inhibiting the rate of muscle protein breakdown, but to increase the anabolic response—meaning synthesis is greater than breakdown—all the EAAs must be consumed.

Leucine and Performance

Leucine is oxidized at an increased rate during endurance sports. This is evidenced in a study published in the Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology. Although a large portion of total energy production isn’t derived from leucine oxidation during exercise, the amount of leucine oxidized is significant in terms of the amount available for incorporation into protein.

In other words, the increased oxidation of leucine during exercise can make its availability—or lack thereof—limiting for the production of new muscle protein.

This is why it’s necessary to consume EAAs in general, and leucine in particular, post exercise. Consuming protein shakes, whey protein, or EAAs after exercise will not only prevent the loss in muscle protein that would occur otherwise (because of the oxidation of leucine) but will also increase muscle protein synthesis and increase muscle strength and function.

Leucine and Type 2 Diabetes

We’ve known for 50 years that blood concentrations of leucine (and the other BCAAs) are elevated in individuals with type 2 diabetes. This knowledge has spurred theories that the BCAAs, and leucine in particular, are somehow involved in the development of insulin resistance and, ultimately, type 2 diabetes.

A recently proposed theory that’s been gaining popularity is based on the premise that the activation of mTOR may be involved in causing insulin resistance. However, this theory is contradicted by studies that have shown that increasing leucine concentrations in dietary supplements not only doesn’t cause insulin resistance but may also, in some circumstances, actually improve blood sugar control.

Studies have also shown that supplementing with all the BCAAs can improve insulin sensitivity in a variety of insulin-resistant states.

Additional Benefits of Leucine

Leucine serves other functions as well. For example, it:

  • Increases the number of muscle mitochondria—the organelles where adenosine triphosphate (ATP) is generated to fuel muscle contraction during exercise
  • Promotes the growth and repair of bone tissue
  • Stimulates growth hormone production
  • Speeds wound healing

Perhaps the most important takeaway here is that leucine—like most things in life—can’t do what it does alone. It needs the help of all the EAAs to be the magic bullet of muscle building the body needs.

Is leucine the “magic bullet” of muscle building?