Step 4: Monitor your progress
Make the first item on your list your first experiment. "Say the problem is that you're sedentary, and your first solution is to work out with a friend after work," says Duncan Neuhauser, Ph.D., a professor of health management at Case Western Reserve University School of Medicine in Cleveland and another of Alemi's research colleagues. "You might experiment with using your noon hour to make exercise 'dates.' "

After a few weeks, add up the number of times you exercised. If your first solution didn't work, try an evening exercise class or find a park where people walk or run after work. Win or lose, keep notes. "Measure your progress every day," Neuhauser says, "and put the results in chart or graph form. Visual aids are helpful."

The data you gather will also make you aware of your normal variations. You may be more active on certain days of your menstrual cycle, for example, or you may always gain 2 pounds when you spend weekends with certain friends. "The data gathering is not just about keeping track of your weight," Norman says. "It's about tracking the process that affects your weight."