How does greater muscle mass affect metabolic rate?

Greater muscle mass increases the resting metabolic rate because muscle tissue is metabolically active. This means that it requires more energy to maintain than fat tissue does, even when at rest. When an individual has more muscle mass, their body utilizes more calories for daily maintenance functions, leading to a higher basal metabolic rate (BMR).

This can contribute to weight management and fat loss, as a higher metabolic rate can make it easier to create a calorie deficit when trying to lose weight. Additionally, the thermic effect of food and energy expenditure during physical activity remain elevated due to increased muscle mass, further supporting its role in overall metabolism.

The other choices do not adequately capture this relationship, as lower metabolism would directly contradict the established link between muscle mass and metabolic rate, while asserting that there is no effect ignores the physiological evidence. Stating that muscle mass only affects metabolism during workouts overlooks the fact that resting metabolic rate is significantly impacted by muscle mass.