The Secret of Leucine

During my college years, I had the chance to attend the Arnold Classic Expo, with the mass of vendors peddling equipment, supplements, pre-made meals and magazine subscriptions. Would-be Olympia competitors wandered the floor and even a glimpse was near impossible through the thickset of bodies hovering around them at all times. Wandering around, I noticed a row devoid of the crowd with a long offshoot of tables. Down the low-rent corridor stood the first ever Mr. Universe and Mr. Olympia, Larry Scott, behind a portable table topped with canisters of a secret blend of branched-chain amino acids (BCAAs).

This was no ordinary supplement. This particular blend had been used by all the champs of the 60’s,  a secret concoction known only to one man, a mixture so powerful that it turned stick-figured geeks into husky, tree stump pulling monsters. Whoever that person was, he unfortunately took his formula to the grave, and one would think, the world’s greatest physiques would have followed (but they didn’t). Somehow Larry Scott rediscovered the secret formula of BCAAs and sold it for a mere 25 dollars per canister.

I couldn’t wait to meet Larry Scott that day. I had bought four canisters of his mixture when I was a senior in high-school, and guess what—I should have flushed it down the toilet. It didn’t even taste good and it was junk (I believe there are still two tubs sitting in a closet at an undisclosed address in Indiana). When I saw Larry Scott, I wanted to shake the hand of the man who stood at the head of an institution I admired—the Mr. O—and who screwed me out of a hundred bucks.

We didn’t talk much, only the standard fare: “I’m honored to get the chance to meet you,” to which he replied, “Would you like an autographed photo? They’re only 20 dollars.” Not what I wanted to hear while shaking the hand of an icon, but we all need to make a buck.

I declined and he smiled from ear to ear telling me about his rediscovered super-blend of BCAAs (sounds like one of the Russian mythologies, doesn’t it). Then I dropped the bomb. My scrawny ass had consumed two of his cans of crap. I didn’t need to say anything else because my lack of size said it all, as did my expression. I saw an instant switch on Larry’s face from jocular to something near shame. He actually stuttered for a response. “Well, do you get my newsletter,” was all he had to say.

Now you have a little insight into why I dislike BCAA products. Like I said, I’ve been screwed several times, and I tenaciously tracked down research to look for answers dealing with BCAAs. Sure BCAA turnover increases during resistance training and some can stimulate insulin release without the presence of glucose, but none of this convinced me that BCAAs were worth the investment.

And now, from a guy who got screwed by the first Mr. Olympia over a crap BCAA product, I’m telling everyone to take copious amounts of the branched-chain amino acid leucine. Have I sold out? Am I getting a kickback? The answer to both is no and the reason I recommend it and so much of it is simple: mTOR.

The word might sound like a character from the next Transformers movie—em • tore′—but mTOR (an acronym of mammalian target of rapamycin) is one of the most important signalers of protein synthesis in the body, triggering reactions via a large number of downstream targets. Instead of taking crazy supplements or other strange ways of triggering individual protein synthesis pathways, one can stimulate the mTOR pathway and activate several avenues at once.

One of the known ways to activate the mTOR signaling pathway requires a rather large time commitment and special equipment. Normally, you’d pay hundreds of thousands of dollars for this information, but I’m going to tell you for free: it’s resistance training. This shouldn’t come as a surprise since this isn’t the first time I’ve written about resistance training remodeling skeletal muscle at the cellular and genetic level in different ways (insulin-independent GLUT4 translocation, GLUT4 upregulation, myostatin downregulation, and manipulation of several other growth and differentiation factors). In general, mTOR phosphorylation (an indicator of protein synthesis signaling) increases by twofold with resistance training. Hormonal factors, such as insulin and IGF-1, can enhance mTOR signaling as well under conditions of adequate nutritional balance.

It’s easy to manipulate insulin levels, but curb the enthusiasm and put down the Gatorade and Oreos. While manipulating insulin and IGF-1 levels seems like a good idea to trigger mTOR signaling, both are upstream regulators, which means they act through intermediaries and can therefore affect limited activation. To be as efficient as possible, we want some way to directly activate mTOR.

Maybe you’re interested by now, maybe not, but you’re probably not excited. People who know me know I never get excited. They do and say stupid things, just to be ornery, in a feeble attempt to see some sort of emotional reaction. It never works. I’m an even-keel guy with too much to do. I don’t waste energy on outward displays of excitement. What I do do when something captures my imagination or piques my interest, is talk about it incessantly and write about it. That’s what drove me to write the first Protein 2.0 article: my excitement about leucine.

Leucine appears to be a direct activator of mTOR. Using a leucine enriched formula can stimulate protein synthesis via the mTOR pathway to the same or higher degree as resistance training. Resistance training alone stimulates protein synthesis by roughly 40%; leucine, 50%. Some authors suggest using dietary leucine to fight everything from age-related muscle wasting to disuse atrophy.

I’m not recommending forgoing training in favor of leucine supplementation. Leucine may activate the mTOR pathway, but studies have yet to show hypertrophic gains comparable to resistance training. Studies show a synergism between the two, however. Using leucine as part of post-workout nutrition can increase protein synthesis to 145% above baseline, compared with only 40% or so without leucine enrichment. Not using leucine is the slow-boat to China.

Hypertrophy depends on many factors, including overall nutritional status and mTOR appears to be hypersensitive to energy usage and storage through different signaling pathways. Periods of low-nutritional status (weight-reducing diets) negatively regulate mTOR, as does temporary energy deficit at the cellular level, which is produced during long-duration, high-intensity workouts, either of resistance type or endurance types (mediated by AMPK activation, for those interested). That’s probably why I have yet to meet or see a single CrossFit athlete who increased strength or muscle size—all they seem to accomplish is skill at performing CrossFit workouts and massive exhaustion. (Go CrossFit!)

Nutritional status regulates mTOR activity, but leucine still seems capable of triggering and enhancing muscle growth during periods of mTOR downregulation. As studies have confirmed multiple times, high free amino acid (FAA) levels stimulate muscle anabolism and leucine may be the main trigger for this phenomenon while the remaining FAAs add nutritional support.

Layne Norton did a back-of-the-envelope calculation and came to the reasonable conclusion that a meal needs to provide roughly 3.2 g of leucine to activate growth pathways. Insulin may be an upstream regulator of mTOR, but it also increases the potency of leucine on the downstream side. This is the why behind my recommendations for 5 g of leucine supplementation per protein shake, for usage with meals and post-workout. Leucine, supplemented at this level, in combination with food and the extra protein should produce a highly anabolic state and the nutrients necessary to sustain it.

Supplementing in this way should drive anabolism all day, plus accelerate post-workout gains. Even if you can’t afford to take a protein blend with each meal and only supplement with a fast-acting protein post-workout, I highly recommend investing in leucine to take with each meal and post workout. All of my clients use this protocol to either preserve as much muscle as possible during dieting, recover rapidly from strength training, or pack on lean muscle as quickly as possible.

Someone, after my initial Protein 2.0 article, questioned the safety of leucine supplementation because of a position statement from India, a statement not based on any research, but instead on fear and propaganda. Still, I felt obligated to look into the maximum safe level of leucine ingestion for a healthy individual. Everyone may want to be careful because the maximum safe dosage is over 1000 grams per day (greater than 2 lbs). If you’re eating over two pounds of leucine per day, there may be other issues of greater concern, such as explosive diarrhea, but toxicity is not one of them.

So how do I feel about that 100 bucks Larry Scott owes me now that I know there was a secret in the BCAA mix, one that he didn’t even know? I still want my 100 dollars. The product was junk. I’m not naïve about the supplement industry and magazine ads. I’ve sat and talked with other former Mr. Olympias and they tell how it is: whoever pays you the most, that’s the stuff you say you take. Larry, however, didn’t take money from a company selling crap, he started a company to sell crap with his name on it. Maybe I should be more forgiving because if you can’t find any good products to endorse, you might as well sell your own garbage instead of somebody else’s.