Exercise helps preserve muscle, and the more muscular you are, the more calories your body will use
up, even at rest.
If you “diet off” about 8 percent of your body weight over the course of several months without exercising, as much as 40 percent of the weight you lose comes from lean muscle tissue. But if you cut calories and add exercise, only 23 percent of your weight loss will be lean body mass. That means you’ll trim more inches from your figure (since fat is less compact than muscle) while also boosting your metabolism (so you’ll be able to enjoy an occasional snack or sweet without having it automatically stored on your hips).
Researchers at the University of Alabama found that middle-aged adults who worked out with weights three times a week for six months built enough muscle to raise their resting metabolism by 80 to 150 calories a day — about the equivalent of a 20- to 40-minute workout.
You don’t have to pump a lot of iron to reach your goal. Using elastic resistance bands, working out in a pool, or climbing hills can provide the resistance you need to build muscle strength. But for the most benefit, do one or two sets of 8 to 12 repetitions for each major muscle group at least twice a week, and try to lift progressively heavier weights.