Here are two easy ways women can keep from adding pounds: brisk walking and biking. An article in the Archives of Internal Medicine, “Bicycle Riding, Walking, and Weight Gain in Premenopausal Women,” reports that even modest amounts of exercise can be effective. A summary of the findings is in Business Week, June 28, 2010, “A Little Biking May Help Premenopausal Women Stay Slim.” The study found that biking is particularly effective for overweight or obese women. (Sorry, but that casual stroll around the neighborhood at a pace of less than three miles an hour doesn’t have that weight-control effect.)