By now we’ve all heard of branched chain amino acids and know they are fundamental in the building and maintenance of lean muscle mass but what could be so special about them? We’ve heard the same spill about other aminos, in particular Glutamine and Arginine – which I’ve written about in a previous article. What sets these particular aminos apart from the others and why should you pay extra attention to them? Well if you’ve ever had to diet down for a fitness competition, photo shoot, or if you simply wanted to look good while at the beach, you’ve probably experienced the lethargic effects that dieting can cause and this ‘effect’ usually doesn’t subside until one resumes their normal high protein/carb diet. During this transitional period however, the muscles are experiencing a catabolic state (muscle destroying) and to compensate for the loss of fat storage, carb depletion, and potential muscular atrophy (muscle wasting), it’s highly recommended that the branched chain amino acids be incorporated into your dieting or supplement regimen and here’s why.
Branched Chain Amino Acids, (BCAA’s) make up about 1/3 of muscle protein and are made up of three essential amino acids; Leucine, Isoleucine, and Valine. They are essential because the body is unable to make them out of other essential amino acids, meaning they must be ingested with food or supplements. The other 6 amino acids that are also essential but I most likely won’t discuss in a future article are: Lysine, Methionine, Phenylalanine, Threonine, & Tryptophan. As you probably noticed, most amino acids end in ‘ine’ so you can recognize them easier. Two more amino acids are ‘sometimes’ considered essential and they include Arginine and Histidine – these are especially important for the children because their rapidly growing bodies can’t absorb them fast enough so they will need to acquire these necessary aminos elsewhere.
Of the 3 BCAA’s, leucine is the most heavily researched and appears to offer the biggest physiological benefit and is the primary BCAA for muscle protein synthesis – while isoleucine induces glucose uptake into cells which assist in the regulation of blood, the production of hemoglobin, and assist in the blood clotting effects. Valine is used mostly for muscle recovery, tissue repair, and nitrogen balance.
The BCAA’s make up about 40% of the daily requirement of all 9 essential amino acids. Naturally, the BCAA’s are found in protein with their highest concentrations being in foods like: chicken, beef, salmon, eggs, dairy products, soy products, beans/legumes, & whey protein. In addition to food, BCAA’s can be supplemented, which can be useful for athletes and fitness enthusiast because BCAA’s bypasses the liver and flows directly to the blood stream for immediate uptake into the muscles. BCAA’s supplementation may also lower lactate levels after resistance training and improve muscular oxidation, which provides peak performance. BCAA’s also prevents a serum decline, which normally causes a tryptophan influx into the brain, followed by serotonin production, which causes fatigue.
BCAA’s reduce muscle fatigue, expedite muscle recovery, and help to regulate other amino acid intake from the muscles during intense exercise as BCAA’s are rapidly depleted from the muscles when training. In addition, they help the body absorb protein; a deficiency in any one of these aminos will cause muscle loss. Taking BCAA’s immediately after or with a post work out meal will lower cortisol (destroys muscle), levels and replace BCAA’s levels in the muscles faster.
BCAA’s are both anabolic and anti-catabolic because of their ability to significantly increase protein synthesis, facilitate the release of hormones such as growth hormone (GH), IGF-1, and insulin, and helps maintain a better testosterone to cortisol ratio. BCAA’s are also excellent anti-catabolic because they can help prevent protein breakdown and muscle loss, which is significantly important to those who are pre-contest diets. During these times of low caloric intake, the use of BCAA’s is strongly recommended because there is a greater risk of muscle atrophy.
Consuming a carbohydrate, protein, and amino acid beverage during and after training can induce an insulin response, which helps transport BCAA’s into cells. However, availability of leucine is more important than insulin. Within the muscle cell there’s one particular regulatory pathway for protein synthesis that’s stimulated by insulin, but dependent on leucine (Anthony, Mantell 2000). All in all, protein synthesis depends on how much leucine is readily available.
Because it’s so important to have leucine available for protein synthesis, if you train in a fasted state, or don’t eat after physical activity, you’re going to lose more protein than you gain. However, if you consume sufficient amounts of BCAA’s during this time, especially leucine, you’ll enhance protein synthesis. Serving size of leucine alone can range from 4 grams per day (on the low end) to 12 grams per day for bodybuilders. Keep in mind a 6 oz piece of chicken has approx. 2 grams of the BCAA’s leucine so don’t feel so inclined to get it all from a supplement. Conversely, supplements are there to provide additional nourishment due to inadequacies in food intake and are considerably lower in calories than a full meal. I ‘strongly’ recommend (pardon the pun) you check out the supplement section of Fitness RX for Men for an extended selection of products that contain the ‘essential’ branched chain amino acids.