What role does exercise play in weight management?

Maintain weight lost: Exercise has not been shown to contribute much to weight loss, but it is important for maintaining weight loss you have achieved. Being physically active is good for other reasons: it helps lower blood pressure, reduce the risk of heart disease and some cancers, improve mood, and increase stamina. Exercising won't make it harder to lose weight as long as you don't increase your caloric intake.

Be consistent: A wise old doc recently told me of three things that he has seen be helpful to loosing weight and keeping it off. 1) stay active. Not necessarily a lot, just stay active. 2) be aware of what you eat. Not a diet, per se, just awareness. 3) weigh often. That way, you know what your weight is doing and, if you're aware of what you're eating then you can make chances to improve it.

Maintenance: While changing baseline activity/exercise level is important for weight loss.... Regular exercise is even more important to maintain weight loss...

Exercise and Weight : Exercise is a poor tool for weight loss on its own. When you think that an hour of moderate exercise will burn about 300 calories and consuming 1 cookie will add 300 calories to your diet, you can see that you could never exercise enough to compensate for a poor diet. Exercise is useful to increase metabolism but you must reduce calories, especially those from carbs to lose body fat successfully.

Essential: Increased activity is essential to reduce stored caloric intake. Best done is cardio-vascular type - for muscle tone, rather than for muscle bulk.