The only way to remove stored fat is to burn it off. Exercise increases caloric expenditure and the rate of expenditure is related to both intensity and duration of activity. As exercise/running becomes more intense, the duration of participation becomes limited. One may be able to expand 125 calories in one all out mile, but if you run at a comfortable pace for several miles you triple the caloric expenditure without becoming exhausted. This is why it is recommended one do moderate activity instead of high-intensity exercise for weight control.
The effect of exercise does not stop when the individual stops exercising. Often caloric expenditure remains elevated for 30 minutes after you stop. Vigorous long running will elevate body temperature and increases metabolism. When the individual stops, there is a long, slow period when caloric expenditure remains well above resting levels. This post exercise increase in energy expenditure is often neglected when considering the benefits of exercise.
Many think diet is better than exercise for controlling ones weight. It is easier to reduce caloric intake by not eating a piece of cake than it is to burn off the cake after you eat it (2 miles at 120 calories/mile).
“Is diet a better method of weight control?” Studies have clearly indicated the need for exercise in a program of weight control. Diet or caloric restriction can lead to the loss of weight but the loss is often only temporary or the individual goes back to old habits and gain the weight back. Exercise with dieting produced greater weight loss over a shorter time. It not only helps one lose weight but produces other benefits especially for the obese person.