With protein powders having successfully crossed over from niche bodybuilding product to the mainstream, the next supplement being pushed by the fitness industry to the average gym-goer are BCAAs.

These are Branched-Chain Amino Acids, and according to MyProtein, are rapidly growing in popularity amongst more mainstream health and fitness consumers.

Usually consumed in the form of a powder which is added to water to create a translucent liquid, gym-goers can be seen downing BCAAs pre-, during and post-workouts, and also sipping throughout the day.

But what are they for? And do you really need them?