What Are Amino Acids And Why Are They In So Many Nutrition Supplements?
It seems these days that the building blocks of proteins, affectionately known as "amino acids", are tiny little gold nuggets that bestow superhuman powers upon anyone lucky enough to stumble upon them in a sports gel, capsule, fizzy drink or cocktail. After all, these little guys are starting to get put by nutrition supplement manufacturers into just about everything, from your engineered pre-workout snack, to your during workout beverage, to your post-workout smoothie mix.
But why are amino acids so prevalent now?
And more importantly, do amino acids actually work?
We're about to find out, and have a bit of fun in the process.
Back in biology class, it was convenient to think of a muscle like a big Lego castle (or Lego pirate ship, depending on your tastes), and amino acids as all the little legos that made up the giant Lego structure (your muscle). Convenient, yes. Complete, no. The role of amino acids goes beyond building blocks - they are essential for the synthesis of proteins, enzymes, hormones, neurotransmitters, metabolic pathways, mental stabilization, and just about every function that takes place within the human body. So using the Legos-are-amino-acids example, a more appropriate analogy would be that you dump all the Legos out of the box and they self-assemble in a magic pirate ship, then float into the air and fly around the room shooting miniature cannon balls.
In other words, the function of amino acids goes far beyond simple "building blocks".
In the nutrition supplement industry (when I use that word, it seems to denote big fat guys in black suits sitting around an oak conference table, but in reality, most of these folks are skinny athletes in white shoes and shorts), amino acid supplements fall into two basic categories: Essential Amino Acids (EAA's) and Branched Chain Amino Acids (BCAA's).
Essential Amino Acids
Essential amino acids, as the name implies, are essential because they can't be made by our bodies, like all the other amino acids. Instead, we have to get them from our diet. Have you ever heard of Private Tim Hall, AKA Pvt. Tim Hall? If you're a biology or chemistry geek, you probably have, because he's the pneumonic commonly used to remember the essential amino acids, which are Phenylanine, Valine, Threonine, Tryptophan, Isoleucine, Histidine, Arginine, Leucine and Lysine. Thanks Tim, we'll send you a check if we ever win money in Biology Trivial Pursuit.
Anyways, let's take a look at why the heck Pvt. Tim might do us good during exercise, starting with P.
Phenylalanine is traditionally marketed for it's analgesic (pain-killing) and antidepressant effect, and is a precursor to the synthesis of norepinephrine and dopamine, two "feel-good" brain chemicals. This could be good because elevated brain levels of norepinephrine and dopamine may actually lower your "RPE" or Rating of Perceived Exertion During Exercise, which means you could be happier when you're suffering hallway through a killer workout session or Ironman bike ride.
Valine, along with Isoleucine and Leucine, is a real player, because it is BOTH an Essential Amino Acid and a Branched Chain Amino Acid. Valine is an essential amino acid. It can help to prevent muscle proteins from breaking down during exercise. This means that if you take Valine during exercise, you could recover faster because you'd have less muscle damage. More details on that in the section below on BCAA's.
Threonine research is a bit scant. I personally couldn't find much at all that explained why threonine could assist with exercise performance, but would hazard a guess that it is included in essential amino acid supplements because it is just that: essential. And many of the studies done on EAA's just basically use all of them, rather than isolating one, like Threonine. For example, and this is a bit interesting for people who are masochistic enough to like working out starved, there is a significant muscle-preserving effect of an EAA + Carbohydrate solution ingested during training in a fasted state, and decreased indicators of muscle damage and inflammation. This basically means that if you popped some essential amino acids, even if you did not eat anything, you might not "cannibalize" as much lean muscle during a fasted workout session.
OK, sorry, I got sidetracked there.
Tryptophan is an interesting one. It is a precursor for serotonin, a brain neurotransmitter that can suppress pain, and if you're taking some before bed at night, even induce a bit of sleepiness. The main reason to take tryptophan would be to increase tolerance to pain during hard workouts, games or races. But studies to this point go back and forth on whether or not that actually improves performance.
Isoleucine, another BCAA / EAA combo, has some of the same advantages of Valine. More on BCAA's in a bit.
Histidine, as the name implies, is a precursor to histamine, and actually has some antioxidant properties and plays a key role in carnosine synthesis. Looking back, that sentence I just wrote is not very user-friendly, and is pretty much just geek speak. Here's a clarification: histamine could help you fight off the cell damaging free radicals you produce during exercise, and carnosine helps you get rid of muscle burn more quickly, and helps turn lactic acid back into useable muscle fuel. So hooray for histidine, it gets a gold star sticker.
Next is arginine, and if you're reading this and you're an old man who has relied on a little blue sill to have a happier time in the sac, you can thank arginine. Arginine helps with nitric oxide synthesis, and nitric oxide is a vasodilator that increases blood flow and could help with exercise capacity (in the case of the blue pill, for one specific body part). Most of the studies on arginine show that it really helps folks with cardiovascular disease improve exercise capacity, and like tryptophan, the studies go back and forth on whether it really helps with the athletic population - but it has a great deal of promise.
Leucine is yet another BCAA / EAA combo. We'll get to BCAA's in about 30 seconds, depending on how fast you read.
Lysine is something my Mom used to take to help cold sores that she got from eating citrusy foods. That's basically because it helps heal mouth tissue. But more importantly for exercising individuals, lysine may actual assist with growth-hormone release, which could vastly improve muscle repair and recovery, although if you take lysine in it's isolated form, the amount you'd have to take to increase growth hormone release would cause gastrointestinal distress, or as I like to it, sad poopies. But combined with all the other essential amino acids, there may be a growth hormone response in smaller doses, and there is some clinical evidence that essential amino acid supplementation could stimulate growth hormone releasing factors.
That about wraps it up for essential amino acids. The only thing I did not mention is that they may have a bit of an insulin and cortisol increasing effect. Before you draw back in shock and go flush all your essential amino acids down the toilet because you heard insulin and cortisol make you fat, remember that both insulin and cortisol are crucial (in smaller amounts) for the "anabolic process", or the growth , repair and recovery of lean muscle tissue. The amount you get in essential amino acids is far different than the stress and insulin / cortisol response you get from eating a pint of ice cream while you drink whiskey and work on an all-night project for work.
Branched Chain Amino Acids
BCAA's include leucine, isoleucine, and valine. They're interesting (at least to people in white lab coats) they are metabolized in the muscle, rather than in the liver. This means that BCAA's can be relied on as an actual energy source during exercise, and could therefore prevent premature muscle breakdown. There was actually one compelling study done by a guy named Ohtani that showed exercising individuals who got BCAA's had better exercise efficiency and exercise capacity compared to a group that did not get BCAA's.
Other studies have found that BCAA's could increase a ton of factors that are really useful for an exercising athlete, like red blood cell count, hemoglobin, hematocrit and serum albumin, and could also lower fasting blood glucose and decrease creatine phophokinase, which means less inflammation , better red blood cell formation, and better formation of storage carbohydrate. BCAA supplementation after exercise has been shown to cause faster recovery of muscle strength, and even more interestingly, the ability to slow down muscle breakdown even during intense training and "overreaching" (getting very close to overtraining). Just Google the branched chain amino acid studies by Sugita and Kraemer for more on that (yes, shocker, this is a newsletter article, and not a peer reviewed scientific journal report with full citations, because if it was the latter, you'd be asleep by now - so if you're a science nazi, then go get busy on Google scholar).
OK, so continuing onto with the many cool things that BCAA's can do: when you supplement with them, they decrease the blood indicators of muscle tissue damage after long periods of exercise, thus indicating reduced muscle damage, and they also help maintain higher blood levels of amino acids, which, if you recall, can make you feel happier even when you're suffering during exercise. Logically, low blood levels of BCAA's are correlated with increased fatigue and reduced physical performance.
Heck, they even use BCAA's in medicine. They could help people recover from liver disease, could assist with improvements in patients with lateral sclerosis, and could help recover in patients who have gone through trauma, extreme physical stress (can you say "Ironman triathlon"?), Kidney failure, and burns .
Summary
So if you've stayed with me so far, here's the take-away message (and thanks to Dr. David Minkoff for helping me with this nice summation):
If all 8 essential amino acids are present, muscle repair and recovery can start before you're even done with your workout - and when you're mentally stretched toward the end of a tough workout, game or race, high blood levels of amino acids can allow the body and brain to continue to work hard instead of shutting down.
Based on all this, do I take BCAA's and EAA's? You bet I do. I personally use http://tinyurl.com/RecEase for BCAA's and Master Amino Acid Pattern (MAP) for EAA's.
