Building muscle improves metabolic rates by increasing the amount of lean tissue in the body. Muscle is metabolically active, meaning it burns more calories at rest compared to fat. As muscle mass increases, the basal metabolic rate (BMR) rises, allowing individuals to burn more calories throughout the day. This can aid in weight management or loss, as enhanced metabolism facilitates greater efficiency in utilizing energy. Additionally, muscle-building activities often improve overall strength and functionality, contributing to better physical performance and health.