Whey Protein: What It Actually Is, And Who Actually Needs It
The most popular supplement in every gym bag. Here's what it does, and whether you're actually one of the people who needs it.
Branched-chain amino acids (leucine, isoleucine, valine) — three of the essential amino acids found in complete protein sources, isolated and sold separately, often flavored for sipping during workouts.
Early research suggested BCAAs alone could stimulate muscle protein synthesis — but more complete research since has shown that a full spectrum of amino acids (from whole protein or whey) does this more effectively than BCAAs in isolation.
Anyone already meeting their daily protein target through food or a complete protein supplement is already getting more than enough BCAAs as part of that protein — additional isolated BCAAs provide little extra benefit in that context.
Training in a fasted state for an extended period, where a low-calorie way to reduce muscle breakdown is useful, is one of the few scenarios where BCAAs offer a distinct advantage over simply eating enough protein around training.