Final answer:
Adequate protein intake is important for adaptations to resistance exercise training such as increased muscle mass and improved strength. Protein provides the necessary amino acids for muscle repair and growth.
Step-by-step explanation:
Adequate protein intake is important for adaptations that occur after a few months of proper resistance exercise training. These adaptations include increased muscle mass, improved strength, and enhanced muscle recovery. Protein is needed for these changes because it provides the necessary amino acids for muscle repair and growth.