The easiest way to monitor your walking progress is to invest in a basic pedometer, which attaches to your waist-band and keeps track of how many steps you take. (Two RS favorites: the $15 Accusplit AL 1540, www.pedometer.com, shown; and the $18 Acumen 10K Stepper, www.pedometersusa.com.)

Most Americans take 5,000 to 7,500 steps a day, or about 2.5 to 4 miles. But people who average more than 9,000 steps a day are more likely to be at a normal weight for their height, according to a study conducted at the University of South Carolina.