Sure, you know walking is good exercise. But heres something you might not realize: You can give your waistline (and other body parts) a serious trimming by tweaking that walk around the block. The three women on the next pages each walked off at least 35 pounds, much of it around the middle, using one of these secret weaponsplyometrics, hills, or intervals. The strategies also strengthened their legs more quickly than plain old walking sessions, so they could walk longer and faster to burn more calories. After six weeks of walking four to six times a week, you will feel stronger and look slimmer where it counts.