Visualization...it works! When you start exercising, either for the first time or just since slacking off for too long, imagine what you want to achieve for yourself. Picture a healthier body. Imagine what it will feel like when you look better, move better, have more energy and have a more positive attitude (because all of those things occur when you exercise). Picturing these benefits may be the difference between making it to the gym or an exercise class that day and not getting there. Let the visualization help motivate you.
"Writing is like driving a car at night. You can only see as far as the headlights, but you make the whole trip that way." - E.L. Doctorow, writer. The same can be said of working out. You won't see immediate results (although you will feel better right away), but results will come with consistency. Set your fitness goals for the near future and for each and every time you work out - goals which support the long-term goals that you've decided to make happen. In fact, make sure each exercise has a clear objective: How much weight are you going to use? How many repetitions are you going for? What muscles are you focusing on? Actually visualizing the primary muscles doing the work in an exercise is a very helpful tool in getting the most out of the exercise. And visualize how great you will feel after sweating a bit and getting your heart rate up or increasing that weight from last week, knowing that you've earned a well deserved rest.