Muscle mass contributes to an increased metabolism as it requires more energy to maintain than fat tissue. The higher the muscle mass, the more calories are burned at rest, leading to an elevated resting metabolic rate (RMR). This increased caloric expenditure, even during sedentary activities, supports weight management and overall metabolic health. Furthermore, engaging in resistance training helps build and preserve muscle, especially important during weight loss, as it minimizes muscle loss while promoting fat loss. Therefore, maintaining or increasing muscle mass is key for enhancing metabolism and achieving fitness goals.