You will be much more likely to exercise regularly if you set realistic goals for yourself. Set both long-term and short-term goals. You can adjust your long-term goals as the short-term goals are met. For example, if you want to weigh 140 pounds but you weigh 200, set a goal for yourself to lose 20 pounds. Then set another intermediate goal. When you get to 150, you may decide that is really the best weight for you and decide to maintain that. If you want to run a marathon but have never run before, your first goal may be to run a mile without stopping. Small successes motivate you to keep going.