It sounds like some suspicious promise from a late-night infomercial: feel 15 to 30 years younger by exercising just one hour a week! Yet that's exactly what happens when you lift weights. Strength training has been shown to decrease insulin resistance, decrease resting blood pressure, reduce arthritis pain, even improve memory. Some experts believe it's as essential as aerobic training: "As good as walking is for a variety of things, it does not address the loss of muscle that accompanies the aging process," says Wayne L. Westcott, Ph.D., fitness research director at the South Shore YMCA in Quincy, Massachusetts, and coauthor of Strength Training Past 50 (Human Kinetics, 2007). That loss of muscle—about seven pounds per decade for men and five pounds per decade for women—causes a slowdown in resting metabolism that then translates into a host of health problems.
Much of that age-related decline in muscle mass can be halted—and even reversed—by strength training. Gary Hunter, Ph.D., a professor of human studies and nutrition sciences at the University of Alabama at Birmingham, found that lifting weights for 30 to 40 minutes three times a week increased the muscle strength of women 60 to 77 years old by almost 40 percent—putting them on a par with 35-year-olds. Other studies have found similar benefits from lifting just twice a week.