Led by Assistant Professor of Psychiatry and Human Behavior John M. Jakicic, researchers asked 115 overweight women ranging in age from twenty-five to forty-five to do the same amount of brisk walking each day. About a third of the subjects were provided with electronic, motorized treadmills they could use anytime at home. The results, published in the October Journal of the American Medical Association, revealed that the women with the exercise equipment lost more than twice as much weight as those without - 16.3 compared to 8.1 pounds.

"The equipment made the activity easier to adopt because it allowed people more flexibility," says Jakicic. Women could use the treadmills on rainy days or at night, for example, and the equipment served as an inescapable visual reminder of the exercise the subjects needed to do.

Home-exercise equipment also allowed the women to exercise in shorter, more frequent bursts. "The treadmills helped participants accumulate the short sessions of activity," Jakicic says. Women who exercised in the house sustained their regimen throughout the eighteen-month study period, while women who exercised outside the home found themselves slacking off. As a result, the treadmill group not only lost more weight but was able to keep it off longer.