Protein is the essential nutrient required for building muscle. It plays a critical role in muscle repair, growth, and recovery after exercise. Protein is made up of amino acids, which serve as the building blocks for muscle fibers. Consuming an adequate amount of protein, particularly after workouts, aids in the synthesis of new muscle tissue and helps prevent muscle breakdown. Common sources of protein include animal products like meat, dairy, and eggs, as well as plant-based options such as legumes, nuts, and tofu. A balanced diet with sufficient protein is crucial for individuals engaging in strength training.