Weight lifting a great way for middle-aged Americans to lose weight

Chances are, if you're a middle-aged American, your waist is bigger than it was in high school. Our metabolism slows down as we age, increasing our belt size. The resulting weight can lead to heart disease, stroke, diabetes and several forms of cancer that are associated with obesity. But here's the good news: You can do something about it. We've been told that strength training doesn't burn as many calories as aerobic exercise (running, biking, walking, swimming, etc.). So those who want to lose weight tend to focus on aerobic activities. Although cardiovascular exercise is essential to long-term health, it's important to understand it does little to offset the slower metabolism of middle age. Past age 30 or so, most people start losing muscle mass. Because muscle is so metabolically active (which means it requires a lot of calories to do its thing), a drop in muscle weight means your body needs fewer calories. Cardiovascular exercise, although good for burning calories, doesn't beef up muscles the way weight training can. Do it two or three days a week, and work the whole body. It may take several months to see the desired effect. Use a bit more weight than you think you can handle, to make muscle tissue stronger and denser over time. Have a qualified personal trainer evaluate your program. You don't have to join a gym. Trainers are widely available and can set up a home program. Tedd Mitchell, M.D., is medical director of the Wellness Program at the Cooper Clinic.