BCAAs and Muscle Development without the Presence of Protein

Here’s a new study from the Journal of the International Society of Sports Nutrition.

Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?

BCAAs – Branched chain amino acids leucine, valine and isoleucine – are a HUGE staple in the nutritional supplement world and are key to developing and maintaining muscle mass.  Something many gym goers and fitness enthusiasts are guilty of is taking our BCAAs alone during our workouts.  There’s an entire industry around that concept, take your BCAA drink or pills during your workout and it will help you build that muscle mass you’re seeking.  However according to the new study by Robert R. Wolfe, this is not the case.

“An extensive search of the literature has revealed no studies in human subjects in which the response of muscle protein synthesis to orally-ingested BCAAs alone was quantified, and only two studies in which the effect of intravenously infused BCAAs alone was assessed. Both of these intravenous infusion studies found that BCAAs decreased muscle protein synthesis as well as protein breakdown, meaning a decrease in muscle protein turnover”

What does this actually mean? The catabolic process, meaning anything that naturally induces the breakdown of larger molecules into several smaller building blocks like what you do with your muscles during a workout, where the protein breakdown exceeded the synthesis persisted during BCAA infusion.  So when you took your BCAAs alone during that last workout, your muscles were torn down at a rate in which the BCAAs weren’t able to help in the muscle protein synthesis process, which is the opposite of the anabolic state.

The anabolic state generally means when your body is in a circumstance in which the rate of muscle protein synthesis exceeds the rate of muscle protein breakdown. There is an assumption that BCAAs will induce this anabolic state by stimulating the muscle protein synthesis. The article goes on to say that the few studies in human subjects have reported decreases, rather than increases, in muscle protein synthesis after intake of BCAAs and they conclude that BCAA supplements alone do not promote muscle anabolism.

So are you taking your BCAAs needlessly? No, you just need to take them in addition to your protein shake. According to the study, “the addition of 5 g of BCAAs to a beverage containing 6.25 g whey protein increased muscle protein synthesis to a level comparable to that induced by 25 g of whey protein.” This suggests that the BCAAs induced a greater potential for the anabolic response of muscle to whey protein.

So don’t go to the gym and take your BCAAs alone thinking they’re doing everything they can to help you build lean muscle.  You need to use these supplements with your favorite protein shake in order to maximize the results and build muscle!

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