1. Friends and Family. Find a friend or family member that has the same resolution as you do. You can get together to compare results, exercise together and rely on each other for motivation. Sometimes it can be easier to quit if no one is relying on you.
2. Write. Write your goals down. If you just make mental notes about your goals you are much more likely to modify them (for the worse) when you original bar is set to high. If you write them down, there's no turning back. You should also keep a journal to track your progress.
3. Include Time Frames. Goals without time frames aren't goals, they're wishes. Give yourgoal a reasonable time frame and stick to it. Don't postpone it and don't give yourself less time than necessary.
4. Expect Problems. Everyone experiences a bad day but quitting after one isn't necessary. If you don't feel like exercising for a day then don't and start back as soon as possible. Changing something major in your life isn't going to happen overnight. Don't let a bad day ruin everything you've worked hard for.
5. Rewards. Reward yourself. Have a cheat day in your diet and take a day off from exercising. Only reward yourself when you reach a milestone such as losing your first 5-10 pounds or getting your mile time under a certain level. You want your reward to motivate you. If you do it too often, it won't have the same effect.