Is there a benefit to drinking BCAAs during a workout?

Is it necessary to supplement with branched-chain amino acids (BCAAs) during exercise or can you just hydrate with water? This is a common question I receive, and the answer is not straightforward. While BCAAs can be enjoyable to drink, the scientific evidence does not support the notion that everyone needs to take them. However, they may be advantageous in specific circumstances.

Amino acids, which are small building blocks that makeup proteins, play an essential role in enzyme activity and molecule synthesis in the body. BCAAs are especially critical for those with muscle-building or muscle-maintenance objectives, as they help regulate protein metabolism by stimulating protein synthesis and suppressing protein breakdown, particularly leucine.*

It’s crucial for everyone to consume sufficient BCAAs, and they can be found in various food sources such as whey protein, casein, eggs, soy, milk, and cheese. BCAA supplementation before exercising can help enhance protein synthesis rates, suppress muscle protein breakdown, decrease markers of muscle damage, and alleviate delayed onset muscle soreness (DOMS).*[1-5]

Muscle Gains

Muscle growth can be facilitated by branched-chain amino acids in various ways, primarily by promoting protein synthesis.*

Upon ingestion, most amino acids are absorbed by the intestines and routed to the liver before being distributed to other body tissues. However, the liver may use them as a source of fuel rather than retaining them for muscle and tissue repair and growth.

In contrast, BCAAs tend to bypass the liver and directly access tissues like muscle, allowing the muscle fibers to determine how to utilize the amino based on their requirements. One of these requirements may involve building up muscle tissue, which is beneficial.

Leucine is the most effective BCAA for stimulating muscle growth in terms of protein synthesis. Similar to how the ignition activates a car engine, leucine triggers the protein synthesis process. Specifically, leucine initiates a complex process called mTOR, which enhances protein synthesis and subsequently supports muscle tissue growth.*[6]

Muscle breakdown recovery

Branched-chain amino acids could potentially exhibit anti-catabolic effects, reducing muscle breakdown (catabolism), and accelerating post-workout recovery.*

Following resistance training, both muscle synthesis and breakdown are heightened, with the latter exceeding the former. This is where amino acid supplements become beneficial. Protein or leucine consumption is required post-workout to overcome muscle loss exceeding growth.

Drinking a solution with 6-10 grams of BCAAs before exercising could result in decreased soreness and faster recovery times.[1]

Enhanced muscle recovery and energy levels

During exercise, BCAAs are catabolized and utilized as a source of energy.[7] A decrease in the levels of circulating BCAAs leads to elevated concentrations of serotonin in the brain, which is believed to partly contribute to exercise-induced fatigue.[8]

Valine is vital in providing energy for workouts. While exercising, a substantial amount of tryptophan is taken up by the brain. The brain utilizes tryptophan to synthesize serotonin.

However, valine competes with tryptophan for access to the brain, and it usually prevails.[9] What this means is that a lesser amount of tryptophan is transformed into serotonin, enabling your muscles to contract with greater force for a longer duration, thereby delaying fatigue.*

The more strenuous and prolonged the workout, the more BCAAs will be utilized as a fuel source. Supplementing with BCAAs can help you work out with greater intensity and for a longer duration, which is crucial for significant improvements in body composition. This benefit is especially pronounced if you exercise in a fasted state.

It’s important to note that consuming BCAAs during fasted training technically means that you’re no longer in a fasted state. Nevertheless, since BCAAs help retain lean muscle mass, it is still beneficial for your metabolism overall.

Better fat loss

Research suggests that supplementing with BCAAs, particularly leucine, may aid weight loss, especially when dieting. Studies have found that BCAAs may regulate satiety, leptin, glucose, adiposity, and body weight. For instance, in a study on competitive wrestlers, those who supplemented with BCAAs while following a low-calorie diet lost more body fat, particularly in the waist, compared to those who took a placebo. Similarly, a study on rats found that leucine supplementation, in combination with a low-calorie diet, led to a significant reduction in body fat.

In another study, mice given isoleucine while eating a high-fat diet gained less fat than mice not given supplemental isoleucine. This effect was due to isoleucine’s ability to activate PPARs, which increase fat burning and inhibit fat storage by increasing the activity of genes that encourage greater fat burning while decreasing the activity of genes that increase fat storage. However, more research is needed to determine the exact impact of BCAA supplementation on weight loss.

When to take BCAAs