Exercising one area will not cause fat to be removed from that area. Men tend to store fat in their abdomens, women store fat more around the hips. Abdominal and hip exercises can strengthen and tone muscle. But those muscles are underneath subcutaneous layer of fat. Only losing weight can reduce the size of that fat layer.
Exercise burns lots of calories.
Many people get discouraged at their slow rate of weight loss and quit exercising. If you stay with exercise you will get more fit and burn more calories. You're one mile walk may increase to five miles, burning 500 calories instead of 100. And since muscle burns significantly more calories than fat, you increase your metabolism even when your body is at rest. If you don't lose weight, there's no point in exercising.