CSSD Practice Exam 2025 – Complete Study Resource

The nutrient leucine plays a crucial role in the regulation of muscle protein synthesis (MPS). Research indicates that an intake of approximately 2-3 grams of leucine is generally considered optimal for effectively stimulating MPS. This amount is significant because leucine acts as a key signaling molecule that activates the mTOR pathway, which is essential for muscle growth and repair.

Consuming leucine in the range of 2-3 grams provides the necessary threshold to trigger this anabolic response without unnecessarily exceeding what the body can utilize at one time. The body has a limited capacity to utilize leucine for muscle protein synthesis, so consuming excessively high amounts does not contribute to a proportional increase in MPS.

This understanding stems from various studies that have highlighted the importance of leucine as the primary branched-chain amino acid involved in muscle anabolism. Ensuring an adequate intake of leucine, therefore, is vital for anyone looking to promote muscle recovery, growth, and overall protein metabolism.