What Is Isoleucine?
Isoleucine is an essential amino acid, meaning it must be obtained through diet as the human body cannot synthesize it. It plays a critical role in muscle metabolism, immune function, haemoglobin production, and energy regulation[1]. Isoleucine is a branched-chain amino acid (BCAA) along with leucine and valine[2], which are important for muscle repair and growth. It is found in protein-rich foods such as meat, fish, dairy products, and legumes. Athletes and bodybuilders often consume the three BCAAs, leucine, valine and isoleucine, to aid in muscle recovery and enhance athletic performance.
Isoleucine and Whey Protein
Isoleucine is prominently featured in whey protein, a popular dietary supplement among athletes and fitness enthusiasts. Whey protein is derived from milk and contains all nine essential amino acids, making it a complete protein source. The high concentration of BCAAs (including isoleucine, leucine, and valine), naturally present in whey protein, makes it particularly effective for promoting muscle synthesis and recovery. Isoleucine, in particular, aids in glucose regulation[2]. Consuming whey protein supplements can help ensure adequate intake of isoleucine, supporting enhanced athletic performance and muscle health.