Overview Making exercise a regular habit is the first step on the road to fitness and wellness. Since adherence plays a key role in the success -- or lack of success -- in any fitness program, personal trainers and group exercise instructors dedicate a significant portion of their professional education to learning and understanding the nuances of intrinsic and extrinsic motivation. Intrinsic Motivation Children provide the best example of intrinsic motivation toward physical activity, explains researcher James R. Whitehead, author of a 1993 paper published in the "President's Challenge." They hop, skip, jump and run around the room simply for the fun of it. Intrinsic motivation helps adults adhere to their fitness programs. They exercise for the sheer joy of pumping blood into their heart and muscles, and circulating mood-enhancing endorphins -- the "happiness hormones" -- produced during aerobic exercise. Extrinsic Motivation The extrinsically motivated exerciser is in it for the rewards, says Jay C. Kimiecik, author of "The Intrinsic Exerciser: Discovering the Joy of Exercise." She exercises to lose weight, to prevent the heart disease that runs in her family, or to lower her blood pressure or cholesterol level. "If only I could lose weight, I could get a better job, convince the object of my desire to go out with me and have more friends," is a common statement amongst extrinsically motivated exercisers. Consequences Health, social acceptance, professional growth and advancement and romantic possibilities are worthy reasons to start an exercise program, but if transforming your body does not bring about the expected life transformation, you set yourself up for disappointment, making it likely that you will go back to a sedentary lifestyle. Intrinsically motivated exercisers may also enjoy the health, romantic and social side benefits of being fit, but mastery of the workout is the key source of satisfaction. The ability to lift more weight, run longer, maintain stability on the balance equipment is the reward. Flow State The ability to reach a flow state might determine the difference between an intrinsically and extrinsically motivated exerciser, says Kimiecik. He devotes an entire section of his book to Mihaly Csikszentmihalyi's theories about flow state during exercise and sport. Flow state describes a total absorption in a physical activity. A clear sense of goals, unambiguous feedback from a coach and a balance between skill and challenge contribute to the ability to reach a flow state during a workout. Reaching this state of mind is more likely to inspire an intrinsic motivation to exercise.