Most people are motivated to exercise when they achieve noticable goals (like losing weight and looking better in the mirror), when someone else compliments them (especially someone they don't know), or when they can visually see progress (like the changes since they started their exercise program). It helps to keep a journal too (like Weightmania Pro), track progress on a calendar, view it on a graph, and take regular progress photos. U.S. government studies have proven when you keep a journal, you're twice as likely to reach goals and typically reach them in less time.