Protein is the macronutrient primarily responsible for muscle repair and growth. Consuming adequate amounts of protein enables the body to recuperate after workouts and build new muscle tissue, essential for recovery and strength gains. It supports the processes of muscle protein synthesis, particularly during the post-exercise period when muscles are most receptive to nourishment. Athletes should ensure they consume high-quality protein sources, such as lean meats, dairy, legumes, and plants, to meet their recovery and growth needs.