I started using branched-chain amino acids (BCAAs) in high amounts in 1994 after meeting with one of brightest minds in exercise physiology and medicine, Dr. Mauro DiPasquale, who wrote Amino Acids and Proteins for the Athlete: The Anabolic Edge. His contention was that if money was an issue, taking supplements during workouts was most important. I still believe that this holds true after playing with them for 17 years.
I like to keep an eye out for new research on BCAAs since they provide so many training and health benefits, of which not all the physiological mechanisms are yet understood. An abundance of new evidence shows BCAAs can support liver health, prevent diabetes, and are essential for longevity and aging well. Plus, emerging data provides more support that you should take BCAAs to stay lean, get strong, recover faster, and have greater work capacity. Let’s review BCAA basics and take a look at what the new research tells us…or if you don’t have the time, just read MY TAKEAWAYS from each study.
The Basics of BCAAs
The BCAAs include leucine, isoleucine, and valine, and they support everything from anabolic muscle building to high-intensity endurance training to improving mental function and mood. They are among the nine essential amino acids that the body is unable to make, meaning they must be ingested through food or supplements. BCAAs are found in high-protein foods such as meat and whey protein.
As their name suggests, BCAAs have a branched side chain that simplifies the job of converting each amino acid into energy during intense exertion. The more BCAAs that are present in the muscles, the more they will be used for energy, slowing the breakdown of muscles cells and preventing catabolism. At the most basic level, BCAAs trigger protein synthesis, increase energy expenditure and have been shown to improve glucose tolerance (glucose intolerance is a precursor to diabetes). What’s exciting about this is that BCAAs work even when you aren’t working out, meaning that if you have to take time off, BCAAs will help minimize fat gain and muscle loss from inactivity. Equally, on days when you don’t exercise, BCAAs are just as important as during and post-workout.
1) BCAAs Enhance Muscle Protein Synthesis
A study in the journal Medicine and Science in Sports and Exercise found that BCAA supplementation can contribute to an anabolic environment in the body. Leucine-enriched BCAAs (a BCAA mixture that is 40 percent leucine) was shown to elevate and prolong protein synthesis after resistance training. There was evidence of a dose-dependent response to BCAAs, meaning that more is better, which is why I suggest taking them before, during, and after training.
BCAA supplementation results in maximal protein synthesis because it increases the intracellular availability of amino acids and activates something called the mTORC1 signaling pathway that is essential for muscle building. Take note that aging is associated with an impaired ability to activate mTORC1 signaling and protein synthesis. Are you getting this? In older individuals, this pathway is not activated to the same extent as in younger trainees after training unless leucine-enriched EAAs are ingested!
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, they will minimize muscle loss and fat gain. A study in the European Journal of Applied Physiology found that giving BCAAs to rats who had their hind-limbs immobilized for six days helped preserve protein synthesis that regulates cell growth. The BCAAs didn’t completely prevent protein degradation and 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.
MY TAKEAWAY: Leucine-Enriched BCAAs Support Muscle Growth And Fat Loss
2) Higher BCAA Levels Correlate With A Lean Body Composition
Research shows that individuals with a higher BCAA intake in their diets have lower rates of obesity, lower body weight, and better body composition. Researchers suggest that leucine increases energy expenditure and improves glucose tolerance. A review in the journal Aging found that BCAAs, and in particular leucine, “appear to have unique obesity-reducing effects” because they decrease food intake and body weight by increasing the gene signaling of that mTOR pathway that I mentioned in #1.
The benefits of BCAAs for a lean physique are confirmed with a large study of 4429 subjects in which those with greater amounts of BCAAs in their diets were the slimmest and had significantly less chance of being overweight than those with lower BCAA intake. Researchers think leucine is the magic bullet for a slim body comp, although only in conjunction with the other BCAAs—a leucine-enriched mixture is best.
MY TAKEAWAY: BCAAs Increase Fat Burning And Keep You Lean
3) BCAAs Result in a Better Testosterone to Cortisol Ratio and Muscle Building
BCAAs will minimize the cortisol response that comes from the stress of exercise. This is ideal because cortisol degrades the muscles and can lead to greater fat gain. Less cortisol means a more favorable testosterone to cortisol (T:C) ratio that will result in faster recovery and more muscle development.
Two studies highlight the role of BCAAs in decreasing muscle protein degradation. A 2010 study found that taking BCAAs in conjunction with resistance training produces significantly higher testosterone levels than a placebo. Participants who took BCAAs also had a lower cortisol response. This is significant because both strength gains and a decrease in protein degradation are more correlated with a better testosterone to cortisol ratio than total testosterone levels.
A new study in the Chinese Journal of Physiology tested the effect of a drink of BCAAs, arginine, and carbs (BCAA drink) on hormone response and psychological state after a single bout of exhaustive exercise. Testosterone was up significantly and the testosterone to cortisol ratio was much more favorable with the BCAA drink than with a placebo. Testosterone was highest at the 120-minute recovery point, indicating a prolonged anabolic effect. Also, participants were given a mood states profile test to measure psychological condition after the extremely intense workout. Participants who received the BCAA drink recovered much more quickly than the placebo trial the decrease in fatigue score at 120 minutes post-workout was significant only in the BCAA trial.
Additional research compared taking 10 grams of protein that was 18 percent leucine with a similar drink that was 35 percent leucine. The higher leucine concentration resulted in greater anabolic protein signaling, which means less muscle breakdown from the degrading effects of cortisol.
MY TAKEAWAY: BCAAs Result In Higher Testosterone And Lower Cortisol Meaning a Better T:C Ratio. Leucine Is Key To This Equation. Hence the high content of leucine in the formula I developed.
4) Greater Strength Gains from Taking Leucine with Training
A British study showed that taking the leucine actually translates into greater strength in addition to the protein synthesis effects I’ve already mentioned. Previously untrained participants ingested 4 grams of leucine a day in conjunction with a 12-week resistance training program and increased strength by 41 percent. A placebo training group had strength increases of 31 percent after completing the same training program.
MY TAKEAWAY: BCAAs Enhance Strength Gains From Training Because They Allow You To Train Harder And Longer.
5) BCAAs Result in Lower RPE and Greater Endurance Performance
Researchers from Sacred Heart University compared taking a BCAA supplement with consuming a carbohydrate beverage prior to a 90-minute endurance cycling trial at 55 percent of maximal oxygen uptake. The BCAA supplement significantly lowered participants’ rating of perceived exertion during the exercise trial in comparison to a placebo group and the carb-supplement group. Additionally, BCAA supplementation raised blood amino acid levels during exercise, a factor that likely has the effect of reducing muscle damage. Researchers suggest that BCAAs can be added to a carb supplement to help lower RPE and allow for more intense training at the same relative level of exertion.
A new study in the Journal of the International Society of Sports Nutrition produced even more impressive results by adding caffeine to the BCAA drink. Endurance-trained men who received the BCAAs had a 2 percent increase in performance during a 2-hour treadmill run over a placebo group. Central fatigue was also lower, which indicates lower RPE during a debilitating endurance trial.
MY TAKEAWAY: Take BCAAs To Stay Strong Longer. BCAAs Are Crucial For Strength And Endurance Athletes.
6) BCAAs Can Decrease Muscle Soreness, Particularly DOMS
A University of Birmingham study found that taking BCAAs at strategic points throughout the day will significantly reduce delayed onset muscle soreness (DOMS) from high-intensity eccentric training. Researchers found a 64 percent decrease in muscle soreness at 72 hours following exercise from BCAAs compared to a placebo. The exercise consisted of 12 sets of 10 eccentric repetitions at 120% of 1RM. If those loading parameters don't produce insanely nasty levels of muscle soreness, nothing will!
A well known Japanese study confirmed that BCAAs decrease DOMS where the exercise consisted of squats for 7 sets of 20 reps with 3 minute rest intervals—my kind of researchers. The subjects were either given a placebo or 100mg/kg of BCAAs (about 9 grams for a 200lb person), with significantly less soreness at 48 and 72 hours after training.
MY TAKEAWAY: Take BCAAs Throughout The Day To Reduce Muscle Soreness From Training.
7) Take BCAAs to Improve Mental Function and Reaction Time
Reaction time, which is virtually untrainable—you’re either born with it or you aren’t, has been shown to improve if you have higher BCAA blood levels. A new study found that a high-protein diet improves mental function and reaction time. Participants who ate a high-protein diet (3 grams per kg of bodyweight of protein a day) performed significantly better on verbal fluency tests and had faster reaction time than participants who only ate 1.5 grams of protein per kg of bodyweight a day. At the end of the study period, the high-protein group had elevated levels of BCAAs, which researchers suggest are the source of the improvements because BCAAs have been shown to reduce fatigue and heighten brain function after heavy training, highlighting their value in post-workout nutrition.
MY TAKEAWAY: BCAAs Are Essential For Brain Nutrition. Boost Your Brain, Especially When Fatigued, With BCAAs. Quick Timing Athletes (Baseball, Basketball, Hockey) Need BCAAs For Peak Performance.
8) Improve Mood and Decrease Depression with BCAAs
Taking BCAAs for the brain is especially important as you age. And I bet that if you ask your parents and grandparents, they aren’t taking BCAAs or even eating a high-protein diet (3 g of protein per kg of body weight). Researchers note that for older individuals who sometimes have difficultly eating enough high-quality protein, BCAA supplementation is essential.
Supplementing with BCAAs will improve production of the neurotransmitters, boosting cognitive function. BCAAs have been shown to play a role in the synthesis of the neurotransmitters glutamate and GABA, which will help you generate energy and drive when you need it and calm you when you don’t.
Additionally, taking 10 grams of essential amino acids, which include BCAAs, has been shown to improve depressive symptoms and overall physical performance in an elderly population. BCAAs likely increased brain serotonin synthesis, improving mood and decreasing depression. BCAAs were thought to have improved participants’ nutritional status by inducing protein building and increasing insulin sensitivity. Researchers point to the importance of leucine (the supplement used contained 2.5 grams), because it is the most important BCAA for protein building.
MY TAKEAWAY: BCAAs Can Make You Feel Better And Get Rid Of Depression. BCAAs Are Essential For The Elderly.
9) Take BCAAs To Protect the Liver and Prevent Liver Disease
Perhaps the most interesting emerging evidence shows that BCAAs will help the liver regenerate after removal of part of the liver. They can also protect the liver from cancer in patients with cirrhosis. Plus, BCAAs improve insulin sensitivity and when improved insulin health is combined with the protective effects in the liver, BCAAs can help prevent fat gain in the liver and avoid non-alcoholic fatty liver disease.
MY TAKEAWAY: BCAAs Protect Liver Health And Prevent Cirrhosis.
10) BCAAs Prevent Diabetes and Improve Insulin Sensitivity
A primary way BCAAs prevent aging and support a lean body composition is by how they improve insulin sensitivity and glucose tolerance. High insulin levels cause accelerated aging along with nerve and cell damage, making it essential to control this hormone. Luckily, it’s the one hormone you can manage and BCAAs will help. Researchers are using BCAAs as a treatment for diabetes and there’s ample data that they lead to weight loss.
A new study in the journal Diabetologia found that the individuals who were in a weight loss study who lost the most weight had the highest BCAA levels—not surprising based on previous evidence. But there was an even stronger correlation between improvements in insulin sensitivity and BCAA levels than weight loss, indicating that the participants overall health and metabolism had improved.
Another study found that rats that were given BCAAs in conjunction with a high-glucose solution, had improved glucose tolerance compared to a placebo group. Glucose tolerance means that once the rats ingested a large amount of glucose and their blood sugar was elevated and insulin was secreted, their bodies managed to process the glucose for energy more effectively than the less tolerant placebo rats.
MY TAKEAWAY: TAKE BCAAs To Prevent Diabetes And Improve Insulin Health. Stay Young And Lean!
11) Live Longer and Improve Your Health with BCAAs
Recent evidence shows that BCAAs have an anti-aging effect and increase the formation of new mitochondria, which can increase energy production. Giving a BCAA supplement to mice resulted in extended life spans and supported cardiac health.
Indirectly, there are other ways that BCAA supplementation can prolong life. As mentioned above, BCAAs promote liver health, and there’s evidence that individuals with chronic liver disease may have better insulin sensitivity with BCAA supplementation. Plus, taking leucine with fish oil and a high protein diet can reduce muscle loss associated with cancer.
MY TAKEAWAY: BCAAs Improve Health And Keep You Young!
12) How and When to Take BCAAs
The critical nature of an organized nutrition protocol is indicated with evidence that protein synthesis is enhanced by BCAA supplementation for up to 24 hours after weight lifting to the point of muscle failure. Training to failure with both 30 percent and 90 percent of the 1RM load will sensitize the muscle to protein feeding for 24 hours after the workout. The key is maximal fiber recruitment versus submaximal—achieving failure primes the body for protein feeding, which should be consumed with BCAAs throughout the day.
For a 90 kg/198 lb man, I would recommend 5 to 10 BCAA capsules 45 minutes before training, and 20 to 30 capsules spaced out evenly during the training session. If you have done plenty of heavy eccentrics or plyometrics, you may want to take an addition of 5 to 10 capsules three times a day with meals for faster recovery. All my students report greater gains from BCAAs paired with as many as 20 capsules of Beta-Alanine Supreme. Some trainees need only a small amount of Beta-Alanine for a muscle-building effect, while those with primarily fast-twitch fibers will get the greatest benefits from 20 capsules.
MY TAKEAWAY: You Must Take BCAAs During Training—Try To Take Them Before And After As Well.