Dwayne N. Jackson, PhD
Amino acids form all the proteins for life and are the building blocks of all muscle; hence, why protein supplementation is so effective for increasing muscularity. Beyond providing the materials for muscle building, many amino acids play several other important cellular and molecular signaling roles in the body, which increase exercise performance and muscular gains. Through capitalizing on these direct cellular and molecular effects, supplement R&D teams have created several safe and effective muscle building amino acid supplements.
Amino acids are classified as essential, non-essential, and conditionally essential. Essential amino acids are those which cannot be produced by the body and must be taken in the diet with food or supplementation. Non-essential aminos are those which can be produced by the body and conditionally essential aminos are those which are produced by the body, but become depleted under certain conditions (e.g., during exercise). From an athletic stand point, there are several essential, non-essential, and conditionally essential amino acids that have been proven as effective ergogenic aids. In this article, we have distilled the science behind 6 key amino acid “must haves” for athletes.
BRANCHED CHAIN AMINO ACIDS
FACTS: Consist of 3 essential amino acids: leucine, isoleucine, valine
SUPPLEMENTAL BENEFITS: Increased strength, focus, energy, muscle building, decreased catabolism
MECHANISMS OF ACTION: BCAAs make up a large proportion of the total amino acid content in skeletal muscle and are readily broken down (catabolized) to produce energy during exercise. Taking BCAAs before and after training ensures that the blood has an abundance of essential aminos necessary to fuel your workout and support recovery, which increases fatigue resistance, protects the body from catabolism, and decreases recovery time. The BCAA leucine also boosts the release of the anabolic hormone insulin. You want insulin levels to be rapidly elevated after your workouts because this hormone carries nutrients such as glucose and amino acids into muscle cells—promoting greater protein synthesis and muscular gains.
DOSING AND TIMING: The BCAA product you choose should have at least twice as much leucine as the other aminos. Take 5-10 g of BCAAs, 3 times daily. Take one dose 30 minutes pre-workout, another immediately post-workout, and one more at any other time of the day.
FACTS: Non-essential amino acid
SUPPLEMENTAL BENEFITS: Mass builder, energy booster, strength booster, pump enhancer
MECHANISMS OF ACTION: In the body, this amino acid is produced by the conversion or combination of other amino acids. Citrulline increases the rate of phosphocreatine and ATP production, which provide the energy that fuels muscle contractions during exercise. In addition to boosting ATP, supplemental citrulline is converted to arginine in your body. Arginine is the precursor to nitric oxide (NO), the gas molecule that optimizes blood flow, nutrient delivery, and waste removal in working muscles— Notably, citrulline supplements increase blood levels of arginine and NO more effectively than arginine supplements.
DOSING AND TIMING: 3-6 grams 30-60 minutes before training.
SUPPLEMENTAL BENEFITS: Promotes immune system support, muscle building, recovery
MECHANISMS OF ACTION: Glutamine is one of the most abundant amino acids in skeletal muscle and is the most prevalent amino acid in the circulation. It is considered a conditionally essential amino acid in athletes, as the body’s supply may not meet demand under conditions of intense training and dieting. Taking glutamine before training has been shown boost training volume and intensity. Loading muscle glutamine levels immediately after training is also important because it is a primary regulator of protein synthesis—which enhances recovery. Glutamine also helps muscle cells load with glycogen, which is critical for muscle size (glycogen pulls water into muscle cells) and energy storage to fuel subsequent workouts.
DOSING AND TIMING: Take 5 grams 30-60 minutes prior to training and immediately post-workout.
FACTS: A non-essential amino acid derivative synthesized in the liver and kidneys from lysine and methionine.
SUPPLEMENTAL BENEFITS: Promotes fat burning, fatigue resistance, anabolism, and enhanced recovery
MECHANISMS OF ACTION: L-carnitine is essential for fat metabolism as it is responsible for transporting fatty acids to the mitochondria to be oxidized and used as fuel by the body. In the world of l-carnitine supplements, the most notable and highly bioavailable forms are acetyl l-carnitine (ALCAR) and l-carnitine tatrate (Carnipure). Scientists developed these forms of l-carnitine to be readily digested, thus boosting the l-carnitine bioavailability and absorption in skeletal muscle and making them more effective than other forms. Carnitine provides antioxidant support, which keeps blood nitric oxide levels elevated, which optimizes blood flow and decreases fatigue in working muscles. Combined with weight training, l-carnitine tartrate boosts anabolism by augmenting testosterone’s effects in skeletal muscle, resulting in enhanced recovery and greater gains. When combined with dieting and cardio, carnitine supplements have been shown to increase fat burning and weight loss without promoting catabolism (muscle breakdown).
DOSING AND TIMING: Take 1-3 g of ALCAR or l-carnitine tartrate, 2 to 3 times per day. Make sure to take a dose of LCLT immediately after training.
FACTS: A Non-essential amino acid synthesized in the body from phenylalanine
SUPPLEMENTAL BENEFITS: Improved mood, focus, and energy
MECHANISMS OF ACTION: Tyrosine is a naturally occurring amino acid that functions as a precursor to the production of many neurotransmitters (e.g., norepinephrine, epinephrine and dopamine). These neurotransmitters are closely involved in fat burning and weight loss, and they play major roles in the brain, controlling motivation, mood, focus, movement and anxiety. Exercise and stress from caloric restriction (while dieting) can severely impact the turnover of these neurotransmitters, making transmitter levels decline. Studies suggest this decline is because the rate of neurotransmitter production is limited by tyrosine. Therefore, taking a tyrosine supplement can combat the adverse effects of severe stress: measures of mental and physical performance, reaction time, mood and fatigue have all been shown to improve greatly.
DOSING AND TIMING: Take 500–1,500 milligrams two times daily, one dose upon waking and the other 30 minutes prior to training.
FACTS: A non-essential amino acid, which reacts with histidine to form carnosine in the body
SUPPLEMENTAL BENEFITS: Increased exercise intensity and volume, strength gains
MECHANISMS OF ACTION: In skeletal muscle, beta-alanine reacts with histidine to produce carnosine. Beta-alanine is the rate-limiting substrate in the formation of carnosine; thus, when it is supplemented adequately, it elevates muscle carnosine levels. Research shows that just 4 weeks of beta-alanine supplementation can increase muscle carnosine levels by more than 60%. Elevated muscle carnosine increases exercise performance through its ability to reduce skeletal muscle acidity during prolonged high intensity exercise. Since fatigue during heavy exercise is exacerbated by the accumulation of acidic metabolic byproducts, it then follows why increased intramuscular carnosine levels would be beneficial to bodybuilders and strength athletes alike.
DOSING AND TIMING: Take 1.6-3 g of beta-alanine 30 minutes before and right after training. On rest days, take 1.6-3 g with breakfast and 1.6-3 g later in the day.