First, what exactly are Branched chain amino acids (BCAAs)? BCAAs consist of the amino acids leucine, isolucine, and valine. BCAAs are important to ingest on a daily basis, but most protein sources already provide BCAAs thus rendering supplementation unnecessary for people with a solid diet.
But BCAAs seem to be in most pre, intra, and post workout supplements these days so clearly there must be a reason, right? You've probably heard that they help to build muscle, improve strength, and speed up recovery among other things, but is this true? Yes, but you aren't being told the entire story.
There are many studies that show the benefits of BCAAs (1, 2, 3), but these studies do not account for the subjects diet or protein consumption in the first place. The truth is that if you eat enough protein daily including pre and post training, then there is no reason to add additional BCAAs to your diet with the exception of fasted training. Fasted training can cause muscle breakdown and in short BCAAs will help prevent that while maintaining your fast.
Furthermore, BCAAs are usually taken to invoke muscle protein synthesis, but studies have shown that muscle protein synthesis is most efficient when the body has access to all of the amino acids, not just the BCAAs. Guess where you can get a majority of amino acids from? Natural food sources such as meat or eggs, or even a whey protein supplement which may be even more effective than BCAAs alone .
So our recommendation is to save your money. If you already have a solid diet and are not doing any fasted training then additional BCAAs really aren't doing anything for you. Instead, take a supplement that is proven to work and can shift your athletic performance into the next gear (as much as a supplement can)!