We tend to gain weight as we age because our metabolism slows. Cutting calories is just part of the weight-control equation. Exercise becomes more important than ever as we get older, not just to boost metabolism and burn calories, but also to maintain muscle mass, flexibility, and bone density. The following exercises all do double or triple duty—a blessing for these busy days.

Yoga and Pilates help build muscle, core strength, and flexibility.

Running boosts bone density, muscle mass, and heart health in a time-efficient workout.

Deep-water workouts, offered at many health clubs, help work your aerobic system while building muscles and core strength.

—D.S.B