These amino acid supplements are most commonly used around workouts to stimulate muscle protein synthesis and offset the potentially catabolic effects of intense training. Although many people swear by the benefits of BCAA supplements, we are going to look at what the research has to say on the matter.
1. Protection Against Exercise-Induced Muscle Catabolism
Reduction of muscle catabolism during training is probably the most commonly reported benefit of amino acid supplementation, and it definitely seems as if the science supports these claims.
A 2004 study published in the Journal of Nutrition demonstrated that exercise increases the requirement for BCAA, and that supplementing with BCAA can help to reduce exercise-induced muscle breakdown.
The researchers concluded by stating that, "[...] BCAA supplementation before and after exercise has beneficial effects for decreasing exercise-induced muscle damage and promoting muscle-protein synthesis; this suggests the possibility that BCAAs are a useful supplement in relation to exercise and sports."
To further support these claims we will look to an earlier study published in the American Journal of Physiology in 1994.
This study also found that, "[...] increased intramuscular and arterial BCAA levels before and during exercise result in a suppression of endogenous muscle protein breakdown during exercise.” Interestingly, removing BCAA from the EAA compound used in this study appear to lower the overall effectiveness of the formula.
2. Improved Fat Loss and Performance During Cutting Phases
Although BCAA have a clearly demonstrated benefit in the context of reducing muscle catabolism during intense training, they also appear to be able to improve success rates during cutting phases.
A 2007 study published in the International Journal of Sports Medicine set out to assess the combined effects of caloric restriction and branched-chain amino acid supplementation on body composition and exercise performance in elite wrestlers.
The researchers concluded by stating that "[...] the combination of moderate energy restriction and BCAA supplementation induced significant and preferential losses of [visceral adipose tissue], and allowed maintainance of a high level of performance.”
What is interesting here is that although the BCAA supplementation did not impart direct improvements to athletic performance, it did allow the subjects to maintain their existing level of performance.
This is particularly relevant in the context of fat loss and muscle retention because of the importance of maintaining strength and overall training intensity.
3. Enhanced Protein Synthesis
"Our results show that EAA have a specific effect on the synthesis of plasma proteins by cultured hepatocytes, and that BCAA at physiologic concentrations account for the major part of this stimulatory effect. Consequently, EAA and particularly BCAA concentration should be elevated in serum-free nutrient media to sustain maximum plasma protein synthesis.”
So we can see from this study that although overall EAA concentrations are important, it is BCAA which provide the bulk of the benefits attributed to amino acid supplements.
4. Improved Overall Recovery Training
So by now it should be quite obvious that a reduction of muscle breakdown and an overall enhancement to muscle protein synthesis should lend itself to improved recovery from training.
If your muscles are regenerating more rapidly while also not being broken down so much in the first place then of course you are likely to be able to train more frequently.
To back this up we will look to one final study which was published in the Journal of Strength and Conditioning Research in 2010, which suggested that:
"[...] short-term amino acid supplementation, which is high in BCAA, may produce a net anabolic hormonal profile while attenuating training-induced increases in muscle tissue damage.”
Of course we already know this by now, but the researchers did conclude with some sage advice:
"Athletes' nutrient intake, which periodically increases amino acid intake to reflect the increased need for recovery during periods of overreaching, may increase subsequent competitive performance while decreasing the risk of injury or illness."
So if you are training hard on a consistent basis and looking to make gains in size, strength, fat loss, or overall athletic performance, then EAA - and particularly BCAA - are an excellent tool to add to your supplement regimen.
Amino acid supplements will help to improve performance and recovery while potentially helping to reduce the likelihood of injury or illness if you are pushing your body to its limits.