The Muscle Geek’s Guide to Amino Acids

Everything you need to know about these muscle-building marvels.

Amino Acids: Fact or Fiction

You’ve heard of amino acids. You have likely heard that they are the building blocks of protein. But do you know what that means, what they really do, and more importantly, why you need them? Read on, and get the all the straight facts you need to help you decide which amino acids are best for you.

Amino acids have been part of training for decades. While their popularity has had a bit of a roller coaster ride, they are now a dominant force in the supplement world and they are here to stay. When used properly, they can have profound effects on your training and thus should be part of every well-designed supplement program. Individually, each amino acid plays a role in various cellular processes and has a unique and specific function, and when combined with other amino acids, or other ingredients, the effect can be quite dramatic at improving muscle building, recovery, immune health, and other important daily cellular functions. More importantly, the timing, the dose size, and the specific combination of amino acids can literally make or break your body’s ability to see the results you are hoping for, so to help you sort out the confusion this discussion is about precision, timing, and efficacious dose size to maximize your muscle growth potential.

Amino Education

A full discussion on every amino acid by function and bioavailability would be exhaustive, boring, and well, quite frankly still won’t help you make the best decisions. Instead we will focus in on a few key educational tidbits, and focus in on the specific amino acids that fuel muscle growth. Of the 20 amino acids in your body, 9 are essential, meaning they cannot be derived on their own and must be consumed by food or supplement. The other 11 (actually to be technically correct there are 10 with the 11th being conditionally essential), can be synthesized by the body in a variety of ways and thus are considered non-essential. “Essentiality” should not be confused with “important”. Several non-essential amino acids are vitally important for body function, however, under normal circumstances, your body knows when and how to make them. So in reality, even with a relatively poor diet overall, you will be fine in the non-essential area. However, to get all of the essential amino acids, you must eat protein or amino acid rich foods and have tight diet to ensure that you get them. Thus, supplementation can play a big role in ensuring you get all the essential amino acids your body needs.

Timing, and efficacious dose size to maximize your muscle growth potential

In theory, since proteins are comprised of amino acid chains, the more protein you consume, the more amino acids your body gets. While simply ingesting more protein sounds simple enough, there are many complicating factors such as absorption and bioavailability which we should take into account. Digestion kinetics are complex, and many unknowns still exist when it comes to the timing and totality of protein breakdown. I don’t need science to back that up because it is the process of scientific inquiry in and of itself that supports it. Why? If we knew how much protein and amino acids your body needed, we’d simply tell you exactly how much and when. To further complicate things, there are many sources of protein, and each type of food source has varying amounts of total protein and amino acid combinations. Despite all the knowledge we appear to have, there is no clear consensus as to the best protein source for a given function and level of bioavailability, and the protein debate continues to get deeper.  That being said, the focus here will remain on the amino acids themselves.

We can eliminate some of the confusion if we go right to the bioactive components. I am not advocating removing or eliminating protein supplements and simply going straight to amino acids altogether, as many other vital nutrients would be lost in the process, I am simply suggesting that if there is a specific need and amino acid can do the trick, why not try it? Thus consuming essential amino acids, especially the branched-chain forms, has a positive and lasting effect on muscle-building, and if that is one of your goals, no matter who you are, you need to add them to your diet and your training program.

Nutrient Timing’s Potential Role in Muscle Growth

Over time, your muscle will grow bigger and stronger

While we can acknowledge the science is still unclear as to all of the benefits and issues surrounding protein, there is one thing that has been well-studied and understood but is also intuitive in terms of thinking. We do know that when muscle is exercised it begins to weaken, and the protein strands and structures that maintain it begin to break down. And we know, without doubt, that muscle needs to be repaired in order to continue building its shape and size. The intuitive part is to make sure that building material is available to begin the repairs and that the needed elements to trigger protein synthesis are present as well. Makes sense right? Since amino acids are the building blocks, if you have enough on hand you should be good to go. Furthermore, since we know certain amino acids are directly connected to the process of muscle protein synthesis (building new protein strands), if we timed our consumption of specific amino acids, we should improve the process. While it is far more complicated than I have made it sound, suffice it to say that you can time your amino acid consumption around your workouts. Even if you don’t know exactly how much or when, you can deduce it should be before, during, and after your workout as that is when muscle is in most distress. You could instead choose to eat protein in the form of regular food or even as a supplement, but again, digestion and timing become an issue. Thus amino acid consumption during this time period, as backed by research, shows marked improvement in muscle recovery and rebuilding. However, research does indicate that consuming protein both before and after exercise in general is far better than nothing at all. Additionally, since it takes days for muscle to fully repair after strenuous workouts, if you continue to consume protein, you will give your body and muscles the vital nutrients that it needs. Over time, your muscle will grow bigger and stronger at a faster rate due to its constant supply of amino acids and protein.

The Amino Acid Difference

Amino acids are classified by their functionality and their availability. As mentioned, essential amino acids must be consumed through the diet, where non-essential aminos are internally constructed. It’s not that non-essential aminos are not important, in fact quite the opposite is true, you absolutely need them, but since your body can produce all the non-essential aminos it needs, it is likely that with a normal diet, you don’t necessarily need to consume any extra. But having said that, there are several non-essential amino acids, like glutamine, glycine, and tyrosine, that when consumed specifically on their own, can improve several other body functions. Within the essential amino acid group there are a small family of uniquely structured amino acids called Branched-Chain Amino Acids or BCAAs for short. Their unique structure of having “two tails” or being branched has specifically classified them in this subgroup, but whether it is their structure itself or not, they play a critical role in enhancing the effects of training and thus should be strongly considered as part of your supplement regime.

BCAAs Specifically For Muscle Growth

While all of the essential aminos are needed for your body to develop efficiently, it appears that the BCAAs are the most successful at stimulating Muscle Protein Synthesis (MPS); the process of rebuilding new protein strands which further thicken and strengthen the muscle cell. Individually Leucine, Iso-Leucine and Valine, the only aminos with branched tail structures, compile the BCAA profile. Fortunately, the three of them combined, seem to have powerful effect on muscle building, not because of their shape necessarily but because of where they are utilized (in the muscle itself) and their function. The BCAAs, and in particular, Leucine, trigger various functions in the muscle building pathway that force a series of steps to take place which ultimately cause the rebuilding of new protein strands. This process, while not completely understood, is downstream (meaning there are other functions and processes that still occur and support cell function) from main cellular activity and is perpetuated by the activation of a conduit known as the mTorr Pathway. While the science is complicated, the result is not. Increased mTorr activation means increased protein synthesis, which means building bigger, stronger muscles. For me, that simply means that I need to add them to my training program. Thus, when it comes to muscle growth and structural development of cells, the Branched Chained Amino Acids (BCAAs) rule the strength and sports performance world.

The BCAA Edge

Having a combination of three BCAAs appears to be an effective strategy in improving MPS, improving recovery and reducing fatigue while maintaining adequate blood amino acid levels. When isolating muscle growth, all aminos take a step back from the power of Leucine. However, both Iso-Leucine, and Valine bring a few other potent characteristics to the show. Both have an effect on protein synthesis but also aid in providing energy by sparing glucose, possibly improving the fat burning process, reducing internal tissue stress, and giving support to other processes within the muscle cell. So knowing the benefit of each of the individual BCAAs, has given rise to the idea that a specific ratio of each is needed to maximize your muscle-building potential.

The Science Behind The Ratios

Often, in BCAA based products, supplement companies have touted some ratio that is supposedly better than another and has furthered muddied the water for consumers. The truth behind the BCAA ratio most commonly cited as 2:1:1 (Leucine: Isoleucine: Valine), is a bit of mystery but stems back to research done in the late 70s by a group out of Italy. The reason behind the selection of that specific ratio at the time was due to the absorption profile of leucine versus the other amino acids, and thus the famous 2:1:1 ratio was created. In reality, this ratio may be correct or it may not, as the specific functioning behind each amino acid has not been tested against others in varying ratios. Thus most studies that have shown the superiority of the 2:1:1 ratio have done so on its own and not in comparison to other studies. In other words, most BCAA studies have compared BCAAs in the 2:1:1 ratio to either protein or some other compounds instead of against one another. That being said, a body of research did show that a 2 gram dose of leucine on its own is less effective than 2g of leucine and 1g each of isoleucine and valine combined. Newer research, however, has not only suggested that much higher concentrations of Leucine (in excess of 3g to as much as 10g) are better at stimulating the protein synthesis pathway, but also that  the ratio of Iso-Leucine and Valine to Leucine may not be as important as once thought. This trend towards higher Leucine ratios (more Leucine, less Iso-Leucine and Valine) has led to the belief that more Leucine is likely a better approach. For that reason, it has even been suggested that neither isoleucine or valine is needed, and while that may be true specifically for pure activation of the mTorr pathway and MPS functioning, the jury is still out, as each BCAA has functions necessary for overall development.

2:1:1 ratio should be considered as the basis

Since no research exists comparing 2:1:1 to other ratios (such as 4:1:1 or 8:1:1 or 3:2:1), it is not truly possible to suggest that any ratio is better than another. However, it is well understood that at least 2g of Leucine is needed and that the other BCAAs may add some other benefits to overall training and recovery processes. Thus the 2:1:1 ratio should be considered as the basis for your amino acid products. Further evidence has shown that specific bonds of each of the BCAAs with either themselves or other amino acids may be even more effective at improving absorption and utilization. Di-Peptide (2 amino acids bound together) and Tri-Peptide (three amino acids) bonds are becoming increasingly more studied within the research world and more utilized in products in the supplement world. While again, the ratios and specific bonds have not been compared across all possibilities, the theoretical possibilities seem very positive, and the anecdotal and practically applied evidence would lend strong support to the fact that peptide bonds may be the wave of the future.

Choose Appropriately

Rather than give you an exact recommendation, the take-home message here is that you need to add BCAAs to your training program, and that the choice of ratio should be grounded in your end goal. First, you need to get adequate supplies of all essential amino acids. Second, the extra consumption of non-essential amino acids could be beneficial. Third, BCAAs without doubt help improve performance. Increasing Leucine consumption will help increase muscle size, density, and strength, as well as improve recovery. Adding Isoleucine and Valine may help further improve recovery, speed up metabolism, and improve overall cell functioning. For that reason, they too should be considered. While the exact ratio may not be as important, if you take leucine alone, you may be leaving a valuable aspect of training on the table by not taking a more complete BCAA. Those of you who have more muscle or want more muscle should certainly consider getting 3g or more of Leucine before, during, or after your workout, but also should consider taking as much as 10g throughout the day. If you have the other BCAAs, then shoot for 5g or more total BCAAs per serving. No matter how you cut it, if you are not using BCAAs and amino acids in general, you should be. While the exact process of MPS is still unclear and the BCAA optimal ratio is unknown, the evidence strongly supports BCAAs for improving every aspect of both weight room and on-field performance, and thus should be a staple in every supplement program.

Check out our list of Amino Acids and BCAAs

By David Sandler, MS, CISSN, CSCS*D, RSCC*D, HFD, HFI, FNSCA, FISSN

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