Many people set goals and immediately talk about how they'll reward themselves if they achieve them. While such rewards would indeed be deserved, they are not the best way of motivating oneself.
Fear of pain is much greater than desire for gain. Simply put, people will do a lot more to avoid suffering pain than to experience pleasure.
Therefore, a much better means of motivating yourself is to choose not what will give yourself if you achieve your goal, but rather what you'll give away should you fail in your attempts.
Think of one of your most prized possessions. It may be your wide-screen TV, your top-of-the-range mobile phone or perhaps your laptop computer. Whatever possession you choose, it must be something that you'd really hate to lose.
The more pain you associate with it being taken away, the more you'll be motivated and driven to achieve your goal.
Vitally important is that you commit to such a pledge and that you truly feel the fear of such a potential loss. The best way to do this is to set your goals with a friend, together with the failure forfeits involved.
Do this correctly and every decision you make, regarding the foods you eat and exercise you take, will be positively influenced by the thought of pain should you fail to reach your goals.