most people know that exercise keeps muscles strong. but did you know that strong muscles burn more calories? muscle mass is metabolically active tissue. in other words the more muscle mass you have the more calories you burn even when you're not working out. studies estimate that for each pound of muscle you add to your body you will burn an additional 35-50 calories per day. so an extra 5 pounds of muscle will burn about 175-250 calories a day or an extra pound of fat every 14-20 days. because guys have more muscle mass they burn calories faster and lose weight more easily than girls. so girls need to work out daily to stay strong and in shape.
how does exercise affect my muscles?