You want to get in shape. Maybe you've made yet another New Year's resolution to do it. So what's stopping you? You've probably read about the long-term benefits of exercise: disease reduction, longevity, weight loss. But as anyone who has tried -- and failed -- to adopt a regular fitness routine realizes, knowing that exercise will benefit you in the distant future isn't the best motivation.

People who successfully maintain a workout regimen learn to shift their focus from distant, external outcomes like losing weight to positive, internal experiences in the here and now. They become what I call "intrinsic exercisers." And you can become one, too.

The philosophy of intrinsic exercise is my own, but it is based on years of scientific research that I have synthesized to create a whole new way of thinking about fitness. A seminal paper on intrinsic motivation by Robert White, Ph.D., for example, was published in the Psychological Review back in 1959. Other parts of the theory are derived from the groundbreaking work of Mihaly Csikszentmihalyi, Ph.D., on the concept of flow. Numerous studies on motivation and physical activity have been published since then, but people remain unaware of their findings. So I have reworked and unified this research to create a more complete picture -- the theory of the intrinsic exerciser.

The core concept behind intrinsic exercise is to exercise for its own sake. Because if you don't get something out of every single run or spinning class you take, you won't keep doing it. You will need to achieve four specific mental states to develop a mind-set powerful enough to motivate you to exercise -- and like it -- under any life condition. They are: personal meaning orientation, mastery, inner synergy and flow.

Personal meaning orientation helps you find exercise rewarding in and of itself. How? First, you use exercise to explore who you are. Intrinsic exercisers articulate why they are working out and what they hope to get from it. Only when exercise becomes personally meaningful will you be motivated to do it regularly.

Next, you learn to monitor improvements in your own performance, a concept known as mastery. Intrinsic exercisers focus on challenging themselves and meeting personal goals, like lifting five more pounds, instead of comparing themselves with other people, which can be frustrating and intimidating. A mastery focus keeps you motivated.

Personal meaning orientation and mastery connect you to your workouts. Inner synergy and flow help you stay connected.

As business guru Stephen Covey once explained, we all have four basic needs--physical, mental, social and spiritual. Inner synergy refers to their integration. By linking exercise to every other area of your life, you'll want to keep doing it. For example, you can use exercise to practice concentration or to socialize by meeting a friend for a jog. Physical activity can also be a way to explore your own spirituality: Running in a charity marathon or simply taking a walk outdoors, for example, can help you meditate on the natural world and forces beyond yourself.