Branch Chain Amino Acids
By Poliquin Group™ Editorial Staff
One of the most effective ways to be lean and strong for life is to familiarize yourself with the branched-chain amino acids (BCAAs). A few of the most compelling reasons to know about BCAAs include the following:
The Basics of BCAAs
The BCAAs are made up of three essential amino, leucine, isoleucine, and valine. They are essential because the body is unable to make them out of other amino acids, meaning they must be ingested through food or supplements. The BCAAs make up 40 percent of the daily requirement of all nine essential amino acids, indicating their importance.
Are BCAAs Worth It?
A common question is whether BCAA supplementation is “necessary” or “worth it” for athletes and body builders. Despite the fact that there’s boatloads of research showing BCAAs improve protein synthesis both after resistance training and in the absence of exercise, there’s not much evidence that this actually leads to greater muscle mass gains in the long term.
It appears that total protein intake above a threshold roughly defined as 1.5 g/kg is most important for gaining muscle from resistance exercise. Foods with a high BCAA content, such as whey protein, have been shown to produce greater muscle gains with resistance training.
#1: BCAAs Enhance Muscle Protein Synthesis
BCAAs are well known for triggering protein synthesis. Combining BCAAs with resistance exercise results in maximal protein synthesis because they both trigger something called the mTORC1 signaling pathway that is essential for muscle building.
The BCAAs along with alanine, aspartate, and glutamate are all taken into muscle tissue for energy. It is suggested that muscle is designed to burn BCAAs for energy during exercise, making a large pool essential for performance.
Another great benefit of BCAAs is that if you have to take time off from training due to injury, a need for a break, or lack of time, increasing your BCAA intake will minimize muscle loss. In addition, because BCAAs trigger protein synthesis even in the absence of exercise, the preservation of lean muscle tissue can keep metabolism up and help prevent fat gain when inactive.
For example, in a rodent study, giving BCAAs to rats that had their hind-limbs immobilized for six days helped preserve protein synthesis. The BCAAs didn’t completely prevent muscle atrophy in the rats’ hind limbs, but they helped preserve the muscle to a greater extent than a placebo. The BCAA-fed rats also had lower body fat levels following immobilization.
#2: Leucine-Enriched BCAAs Equalize Muscle Building Between Old & Young
The BCAA leucine can increase protein synthesis by as much as 145 percent when you take it after strength training. It’s become popular lately to take leucine alone without valine and isoleucine, however this is not indicated by the literature.
Research shows that when leucine intake is out of balance with the other BCAAs, it can lead to an imbalance in the blood amino acid levels, reducing the anabolic response. A ratio of about 4 to 1 of leucine to the other two BCAs is most effective for muscle development.
For older people, leucine intake with the other BCAAs is paramount. As you age, creating a muscle-building environment in the body is important, but hard to do. Activation of protein synthesis is impaired, dropping off after age 35. This decreased muscle-building effect along with a tendency to eat less dietary protein with aging are the primary contributors to muscle loss and sarcopenia.
Leucine-enriched BCAAs (a BCAA mixture that is 40 percent leucine) are a “cure” for this because they have been shown to elevate and prolong protein synthesis even in older people in a dose dependent manner after resistance training.
#3: BCAAs Increase Fat Burning and Can Support Fat Loss
Surveys show that people with a higher BCAA intake in their diets have less body fat, more muscle, and better body composition. For example, a large study of 4,429 subjects found that those with higher BCAA intake were the slimmest and had significantly less chance of being overweight compared to those with lower BCAA intake.
Researchers think leucine is the magic bullet for leanness, although only in conjunction with the other BCAAs—a leucine-enriched mixture is best. Isoleucine improves glucose tolerance, while leucine increases energy expenditure and fat oxidation. Greater fat mobilization allows for a more flexible metabolism, which can enable fat loss from a combination of training and diet.
#4: BCAAs Support Hormone Balance During Intense Training
For example, a study that tested the effect of “loading” BCAAs with 6 grams of BCCAs for 3 weeks followed by a week of high-intensity resistance training found that compared to a placebo group, the BCAA group had higher testosterone (T) and lower cortisol (C). In addition to a better T:C ratio, the BCAA group had lower biomarkers of inflammation, indicating that they were responding to the training load effectively.
A second study found that by combining BCAAs, arginine, and carbs, trainees had better hormone balance and a better T:C ratio after an exhaustive exercise test compared to a placebo. Participants who received the BCAA drink recovered much more quickly than those in the placebo trial and had a lower fatigue score at 120 minutes post-workout.
#5: BCAAs May Improve Strength Development With Training
A study of untrained young men taking 4 g/day of leucine gained more strength than a placebo group after 12 weeks of training. The leucine group increased strength by an average of 31 percent more on all exercises compared to the placebo group.
A recent large-scale analysis of training studies showed that protein supplementation led to greater increases in leg press strength to the tune of an average of 13.5 kg. This review included a variety of protein sources, but all had a high content of BCAAs even though the actual proportions of amino acids varied.
#6: BCAAs Enhance Endurance Performance and Decrease Fatigue
For example, participants who took 300 mg/day of BCAAs for 3 days and then completed in an exhaustive exercise trial had 17.2 percent greater resistance to fatigue compared to a placebo, due at least partly to greater fat oxidation in the BCAA trial.
#7: BCAAs Decrease Muscle Soreness & DOMS for Greater Training Frequency
A series of studies on both trained and untrained individuals show that BCAAs are worth the time and money to reduce (not prevent) DOMS in response to both resistance and endurance exercise.
For example, taking 100 mg/kg of BCAAs reduced muscle soreness at 48 hours and allowed for faster recuperation of strength in untrained women. That BCAAs were effective in an untrained population is noteworthy because DOMS tend to be more severe in untrained muscles.
A second study of trained men found that dosing BCAAs before and after doing 100 muscle-damaging drop jumps reduced muscle soreness significantly. Maximal strength was decreased 33 percent less than a placebo.
The dosing protocol had trainees take BCCAs for 7 days before and for 2 days after training as well as 20 grams before and after the workout for a total of 280 grams. Researchers point to the steady stream of essential amino acids hitting the blood as the reason BCAAs were so effective in this study.
BCAAs are the gem of workout supplements because by preserving the integrity of muscle fibers and reduce post-workout soreness, you can train at a higher intensity more frequently.
#8: BCAAs Prevent Muscle Loss During Long-Duration Exercise
In addition to improving endurance performance, BCAAs prevent muscle loss during ultra-endurance exercise. For example, it was found that trained athletes who performed a 24-hour-long exercise trial that included 12 cycles of running, cycling, and kayaking experienced significant muscle protein degradation and had evidence of metabolic stress linked with muscle damage. There was a pronounced drop in plasma levels of BCAAs over the exercise trial, which is linked with muscle loss.
Scientists suggest that providing “simultaneous nutritional support” with BCAAs or a high-BCAA containing protein will prevent catabolism by improving the overall energy-burning pool so that amino acids aren’t released from muscle tissue.
#9: BCAAs Improve Insulin Health & May Reduce Diabetes Risk
The BCAA isoleucine improves glucose tolerance on its own, and the whole trio of BCAAs can support insulin sensitivity and metabolic rate for improved body composition. For example, a recent study found that the individuals who were in a weight loss trial who lost the most weight had the greatest improvements in insulin sensitivity and the highest BCAA levels.
One thing that should be noted is that diabetics have dysfunctional BCAA metabolism and taking BCAAs elevates insulin, so they should not be used as a treatment for diabetes. Naturally, diabetics should focus on achieving optimal body composition through diet and exercise and work with their doctor to cure diabetes.
#10: BCAAs Correlate With Longevity and Are Therapeutic
BCAAs are used in medicine to treat liver disease, prevent muscle loss with aging, and reduce mortality risk with cancer. In addition to being therapeutic, BCAAs have an anti-aging effect because they increase the formation of new mitochondria.
In rodent studies, BCAAs have been found to extend lifespan in the same way caloric restriction does, while simultaneously supporting cardiac health.
Take Away: BCAAs Improve Health and Keep You Young. Tell Your Parents and Grandparents!
Wondering where you can get your daily dose of BCAAs? Look no further than the juice bar at the front desk. Ask our friendly staff to add some to your favorite smoothie, and enjoy your workout!