Protein is the most essential nutrient for muscle repair and recovery. When you exercise, especially during strength training or resistance workouts, your muscles experience small tears. Protein provides the amino acids necessary to rebuild and strengthen those muscle fibers, resulting in increased muscle mass, endurance, and recovery. Without adequate protein intake, the body cannot effectively repair or grow new muscle tissue, which can lead to fatigue, soreness, and even muscle loss over time. Good sources of protein include lean meats, eggs, dairy, legumes, tofu, and plant-based protein alternatives. Timing also plays a role — consuming protein soon after exercise helps jumpstart the recovery process. In addition to repairing muscle, protein supports immune function, hormone production, and enzyme activity. While carbohydrates and fats provide energy, protein is the key macronutrient for rebuilding. If your goal is recovery, strength, or lean muscle maintenance, consistent protein intake is non-negotiable.