There are 20 different amino acids in the human body that make thousands of different proteins.
Nine out of the 20 are essential amino acids, so your body cannot produce them.
The branched-chain amino acids (BCAAs) are three of the nine essential amino acids, such as leucine, isoleucine, and valine.
Branched-chain also refers to the chemical structure found in foods rich in proteins.
Can Prevent Muscle Loss
BCAA supplements can help prevent muscle loss. The amount of protein in the muscle is determined by the balance between muscle protein breakdown and synthesis (1).
Muscle waste or breakdown occurs when the breakdown of protein exceeds the synthesis of muscle protein. Muscle wasting is a symptom of malnutrition and occurs as a natural part of the aging process for people with chronic conditions.
In fact, BCAAs make up 35% of the essential amino acids found in muscle proteins in the human body (2).
They contain 40% of the total amino acids the body needs. Thus, it is necessary to add BCAA dietary supplements and other essential amino acids to your diet during muscle-wasting times to prevent or delay muscle wasting.
Several studies have confirmed the use of BCAA supplements to prevent muscle protein breakdown (3, 4, 5).
This can improve health conditions and quality of life for older people and those with chronic diseases.
Can Increase Lean Muscle
Muscle growth is one of the most common elements of branched-chain amino acid supplements. The BCAA leucine stimulates a certain muscle protein synthesis in the body, which is the mechanism of lean muscle building (6).
In one study, people who consumed 5.6 grams of BCAAs after resistance exercise had a 22% higher increase in muscle protein synthesis than those who took a placebo (7).
That said, this increase in muscle protein synthesis is about 50 percent lower than in other studies where people consumed whey protein containing a similar amount of BCAAs (8, 9).
Whey protein contains all the essential amino acids required for muscle building.
Therefore, BCAAs can increase muscle protein synthesis without the other essential amino acids, such as those contained in whey protein or other complete protein sources (10, 11).
Can Reduce Exercise-Induced Muscle Soreness
Some research suggests that, after a workout, branched-chain amino acid supplements can help reduce muscle soreness.
If you are new to exercise, it is common for your muscles to get sore. Such soreness is called “delayed onset muscle soreness” (DOMS), and it occurs after exercise for up to 72 hours (12).
While we do not understand the exact cause of DOMS, researchers believe that after exercise, it results from small-scale tears in the muscles (13).
BCAAs have been shown to decrease muscle soreness, which may lead to reducing DOMS duration and severity.
Several studies show BCAAs decrease protein breakdown during exercise and decrease levels of creatine kinase, a manifestation of muscle soreness (14, 15).
In one study, people who took BCAAs before squat exercise reported decreased DOMS and muscle fatigue compared to those who took a placebo (16).
Supplementing with BCAAs can speed up recovery time.
Can Reduce Exercise-Induced Fatigue
While branched-chain amino acids can help you reduce exercise-induced muscle soreness, they can also help reduce exercise-induced fatigue. Everyone gets tired after exercise at some point.
How quickly your muscles get fatigued depends on several factors, including the intensity and duration of exercise, environmental factors, nutrition, and fitness level (17).
During exercise, the muscles use branched-chain amino acids, causing blood pressure to decrease. The levels of the essential amino acid tryptophan in your brain increase as blood levels of BCAAs decrease (18).
It transforms tryptophan into serotonin in your brain, a change in brain chemistry that is thought to contribute to fatigue during exercise (19, 20).
Participants who supplemented with BCAAs enhanced their mental focus during exercise, which is because of the fatigue-reducing effect (21, 22).
A decline in fatigue, however, is unlikely to result in an improvement in exercise performance (23, 24).
You may also like: 10 Health Benefits of Regular Exercise
Conclusion
The three essential amino acids are leucine, isoleucine, and valine.
Your body cannot produce branched-chain amino acids on its own. Therefore, you must consume foods high in protein.
BCAA supplements can help build muscle, reduce muscle tiredness, and relieve muscle soreness.
In patients, BCAAs can stop or delay muscle loss and reduce chronic disease symptoms.
Since most people get a satisfactory amount of BCAAs from their diet, adding BCAA supplements to your diet will not benefit you.
